Vibrational Strong Light–Matter Coupling Using a Wavelength

Jul 26, 2017 - Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan 5920002, Israel. ABSTRACT: An open microcavity (OMC)...
1 downloads 0 Views 892KB Size
Subscriber access provided by UNIV OF NEWCASTLE

Article

Vibrational Strong Light-Matter Coupling Using a Wavelength Tunable Mid-Infrared Open Microcavity Omree Kapon, Rena Yitzhari, Alexander Palatnik, and Yaakov R. Tischler J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.7b06999 • Publication Date (Web): 26 Jul 2017 Downloaded from http://pubs.acs.org on July 30, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

The Journal of Physical Chemistry C is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Vibrational Strong Light-Matter Coupling Using a Wavelength Tunable Mid-Infrared Open Microcavity Omree Kapon,1,2 Rena Yitzhari,1,2 Alexander Palatnik1,2 and Yaakov R. Tischler*,1,2 1 Department of Chemistry, Bar-Ilan University, Ramat-Gan 5920002, Israel 2 Bar-Ilan University Institute for Nanotechnology and Advanced Materials, Ramat-Gan 5920002, Israel

Abstract An open microcavity (OMC) is an optical system that is composed of two mirrors, where one is fixed and the second is on a movable stage. OMC's enable tuning the optical resonances of the system and insertion of different materials between the mirrors, and are therefore of large scientific interest due to their many potential applications. Strong light-matter coupling of the vibrational transitions of organic molecules with the optical modes of a microcavity generates new polaritonic states in the mid-infrared (mid-IR) spectral region. Here, we achieve strong light-matter coupling in the mid-IR using a low optical-loss OMC, that is, wavelength tunable via a piezoelectric actuator. A thin film of Polymethyl methacrylate (PMMA) was deposited on to one of the mirrors to couple the narrow and intense absorption peak of the carbonyl stretch mode at 1731 cm-1 to the OMC. Polaritonic states are observed in FTIR transmission measurements when an OMC resonance is matched to the carbonyl stretch. By dynamically varying the cavity photon mode around the resonance condition, we determine the normal mode polariton dispersion relation and obtain a maximum Rabi-splitting ħΩR = 7.0 ± 0.18 meV. Different cavity linewidths and Rabi-splittings can be achieved by changing the mirror separation, thus providing control of the coupling strength relative to dephasing. The ability to insert multiple materials inside an OMC and generate strong light-matter coupling over a large range of wavelengths can open new paths toward chemical reaction modification and energy transfer studies in the mid-IR.

Introduction

1 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The strong coupling limit of light-matter interactions occurs when energy is transferred back and forth between the light and matter components of a coupled system at a rate, that is, faster than dephasing and loss processes1. In the strong coupling limit, new eigenstates that are superpositions of the initially uncoupled states are formed which have an energy difference known as the Rabi-splitting, ћΩR. The new states, known as polaritons, can be formed by coupling an electronic dipolar excitation in a material to electromagnetic field. The higher energy polariton state is referred to as the upper polariton (UP) and lower energy polariton state as the lower polariton (LP). Prominent examples that have been extensively studied are the coupling of: (1) excitons to photons in a bulk crystal2–4 (exciton-polaritons) or in an optical microcavity (microcavity exciton-polaritons), (2) surface-plasmons to waveguide modes (surface-plasmon polaritons) or to an optical microcavity5–8 (microcavity surface-plasmon polaritons) (3) excitons to surfaceplasmon polaritons7–9 (plexitons), (4) phonons to photons in a crystal10,11 (phonon-polaritons), (5) molecular vibrations to microcavity photons12–15 (molecular vibration-polaritons), and (6) molecular vibrations to surface plasmon-polaritons16–19 (vibrational surface-plasmon polaritons). Polaritons are characterized by an anti-crossing in their dispersion relation at the energy where the material excitation and the photon components of the system are resonant. Polaritonic states are studied in a numerous fields ranging from quantum optics and quantum computing, condensate physics20–23, single molecule spectroscopy, electrochemistry, Raman spectroscopy24– 31

, light-harvesting, and work function engineering32. Polaritons find applications in a broad

range of contexts including lasers33–40, optical switches41–46, light-emitting diodes47–58, chemical sensors, and solar cells. Microcavity exciton-polaritons are generated when excitonic material is situated inside an optical microcavity and the conditions for strong light-matter coupling are satisfied. The material containing excitons can be inorganic quantum wells59, colloidal quantum dots, and quantum dot platelets, monolayers of transition metal di-chalcogenides, a thin film of organic dye, polymer, organic semiconductor, J-aggregate layer or a combination of organic and inorganic materials. For microcavity polariton systems, the Rabi-splitting ћΩR is determined by the coupling strength and is given by: 

(1) ћ = 2 ∗   −   − 

Where NTLS represents the number two level systems, µ is the transition dipole of a single two level system, EVAC, is the vacuum field strength, and the linewidth of the cavity and ensemble of 2 ACS Paragon Plus Environment

Page 2 of 21

Page 3 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

the two level systems (TLS) are κ and γ, respectively. The vacuum field strength depends on the cavity mode volume as described by the equation: ℏ

(2)  =  

 !

Where ωph is the frequency of photons associated with the particular cavity mode and Vm is the cavity modal volume. The splitting is largest when the linewidths of the cavity and the material are matched. A wide range of studies on microcavity exciton-polaritons has resulted in room temperature polariton Bose-Einstein Condensation, polariton lasers, LEDs, and spin-valves, spanning the visible and near-Infrared spectral ranges

60,61

. Coupling of microcavities to organic

exciton layers using J-aggregates and small molecules has led to polariton OLEDs and giant Rabi-splitting62. Recent studies have demonstrated that strong light-matter coupling can be achieved in the mid-IR using the remarkably narrow molecular vibrational modes of organic materials. Organic materials in the solid or liquid63 phase have been utilized, for example, the carbonyl stretch mode of PVAc and PMMA, the cyanide stretch mode of benzonitrile solution and organometallics complexes64 and the metal carbonyl bond of W(CO)6 and Fe(CO)565,66. The resulting mid-IR vibrational-polaritons have been shown to influence chemical reaction kinetics and visible Raman scattering67,68 and have the potential to yield new sources of infrared coherent light.

They have been shown to induce hybridization of molecular vibrations as well as

hybridization amongst photonic modes and are being investigated for their ability to modify coherent energy exchange dynamics69,70 One of the drawbacks of a traditional microcavity is the fixed cavity resonance structure it possesses. Usually, once a cavity device is grown, the only means to tune its resonance is by adjusting the angle of incident radiation71,72. Performing angleresolved transmission, reflection, and emission measurements, does not allow tuning of the microcavity through a large range of wavelengths and limits investigation to a specific cavity mode. In contrast, an open microcavity (OMC) gives the ability to change the resonant wavelength of the cavity after it has been assembled and to control the parallelism between the cavity mirrors. Changing the cavity length is typically performed by scanning a piezoelectric actuator to which one of the cavity mirrors is mounted. Previous studies have demonstrated

3 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

tunable OMC's in the visible and near-infrared spectral range and there have been several demonstrations of exciton polaritons using OMC's73,74. Here we show a tunable OMC suitable for the mid-IR spectral range and use it to achieve strong light-matter coupling between the vacuum field in a cavity and carbonyl stretch at 1731 cm-1 from a thin film of PMMA. The thin film of PMMA was spin coated onto one of the two mirrors that comprised the OMC. The OMC itself consisted of two separate Ge/ZnS dielectric Bragg Reflector (DBR) mirrors on CaF2 substrates. The DBR's provide high reflectivity compared to metal mirrors, which leads to higher transmission peaks and more signal for optimizing the cavity resonance. Both DBRs were placed onto 3-axis mirror mounts for precise alignment of the mirrors. One of the mirror mounts was placed on a moveable piezo-actuated linear-stage while the second mirror mount was fixed on to an optical post holder. The OMC provides high spectral resolution of the cavity photon resonance over a wide mid-IR range. Leveraging this capability, we can tune the vibrational-polariton states by dynamically changing the cavity resonance. As mentioned previously, in prior works, vibrational-polariton dispersion relations were derived by performing angularly resolved transmission measurements or by fabricating a series of samples with different active layer thicknesses. Here, we obtain the polariton dispersion in the normal direction for a single film by directly varying the OMC resonance and therefore we can tune the polariton ground state energy by changing the mirror distance, which is not possible by angle tuning a fixed mirror spacing microcavity. This consideration could be instrumental in investigating the conditions for achieving vibrational polariton Bose-Einstein Condensation, and chemical reaction modifications. We can also use the OMC to change the number of transverse modes in the cavity, m, and therefore the photonic density of states. Spectrally, the number of cavity modes is determined by measuring the spacing among cavity resonances, νm, namely: (3) m =

ν!#$ ν! %ν!#$

Where m is the number of cavity modes and νm-1 > νm. From the number of cavity modes, we can calculate the optical path, Lop, between the mirrors by the following equation:

4 ACS Paragon Plus Environment

Page 4 of 21

Page 5 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

&

(4) ν = '() !

This affects the Rabi-splitting ћΩR given in Eq. 1 by altering the cavity mode volume, Vm, and hence the vacuum field strength, Evac, as described in Eq. 2. By changing the separation between the cavity mirrors, we can also match the linewidth of the molecular vibrational transition to the cavity resonance to satisfy the impedance matching condition (κ = γ), and therefore generate a more optimized Rabi-splitting relative to polariton dephasing (ћΩR/Γ). It should be noted that the position of the PMMA layer relative to the electric field distribution in the cavity will influence the effective number of two level systems, NTLS, which contribute to the Rabi-splitting in Eq. 1. Since the PMMA film used in these experiments was deposited directly on to one of the OMC substrates, an anti-node of the Electromagnetic (EM) field is essentially fixed at the PMMA/DBR interface. Therefore, for any of the multiple distances between the two mirrors that correspond to the cavity being resonantly tuned to the carbonyl stretch at 1731 cm-1, the EM distribution relative to the PMMA layer will be the same. Hence, whenever the cavity possesses a resonance at 1731 cm-1, the number of molecules coupled to the mode will be a constant NTLS, and the only influences to the Rabi-splitting will come from changes in the cavity mode volume and the degree of linewidth matching. The OMC provides the capability in a single setup to study the vibrational strong light-matter coupling behavior of different materials and combinations thereof, while dynamically controlling the light and matter transitions that are coupled and their coupling strengths. Ultimately, the application of OMC's to generate vibrational-polaritons can pave the way towards modifying chemical reactions and studying energy transfer dynamics in the mid-IR. In the future, it may be possible to use OMC’s to investigate how strong coupling of one vibrational transition can influence the oscillator strength of other vibrational transitions in the material.

Methods DBR mirrors were prepared as described elsewhere13. From profilometer measurements the thickness of the PMMA is 3 µm.

5 ACS Paragon Plus Environment

The Journal of Physical Chemistry

Microcavity Assembly and Optical Characterization. The OMC was formed by mounting the DBR coated substrates onto 3 Hex Adjusters XYZ (POLARIS-K1S5, Thorlabs) that were positioned a set distance away from each other using a piezoelectric actuator driven linear stage (HR-1, Nanomotion,). The stage provided long travel (10 mm) and high position accuracy (10 nm in closed loop), and a software interface (X-Commander). The optical components were fixed onto an optical breadboard. The OMC apparatus was situated in a FTIR system (Magna 550, Nicolet) to perform the IR transmission measurements. The spacing between the OMC mirrors was varied between 20 and 130 µm. Attempts to bring the mirrors closer did not succeed in producing repeatable transmission spectra with distinct resonances. Evidently, irregularities in the substrate or imperfections in the mirror alignment are limiting tuning these OMC's.

Results and Discussion A tunable low-loss OMC was assembled for the mid-IR range using two Ge\ZnS DBR's as the mirror layers. The position of one of the mirrors was fixed while other mirror was mounted on a

300

130 µm 36 µm 20 µm

(a) 250 200 150 100 50 0 1000

1500

2000

2500

3000

-1

Wavenumber(cm )

Normalized transmission[%]

movable piezoelectric stage that provided a step-resolution of 10 nm. By controlling the distance

Normalized transmission[%]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 21

300

(b) 250

130 µm 36 µm 20 µm

200 150 100 50 0 1500

2000

2500 -1

Wavenumber(cm )

Figure 1. (a) Normalized transmission spectra of the OMC structure, which includes the PMMA layer and air gap, indicate the change in the optical mode density as a function of mirror separation. (b) Zoom in of the Fabry-Perot resonances in the region of the DBR stopband. For the mirror separation of 130µm, the spectral spacing among cavity resonances has decreased to the extent that two of the resonances overlap with the absorption spectrum of the carbonyl stretch of the PMMA film. Subsequent transmission spectra are offset by 100%.

6 ACS Paragon Plus Environment

Page 7 of 21

between the two DBR's, we tuned the cavity resonances and changed the separation among adjacent modes, i.e. the free spectral range (FSR), as function of the distance between two mirrors as shown in Figure 1. The transmission spectra were normalized each one relative to its own peak transmission value. As described in the methods section, a PMMA layer was incorporated in the OMC by spin-casting a thin film of the polymer on top of one of the DBR coatings. From the spectra shown in Figure 1 and the spectral separation among the transmission peaks, using Eq. 4 we calculated the optical path length and deduced the actual distance between the mirrors, taking into account the different refractive indexes of the PMMA film and the air gap (nPMMA = 1.49)13. From the optical path-length, Lop, we then determined the actual distance between the mirrors according to the following equation: 5 +,--. ',--. + +01 '01 = '() Where n is the refractive index of a given region. For Lop = 21.5 µm, and accounting for the PMMA thickness of LPMMA = 3 µm and PMMA refractive index of nPMMA = 1.49, then Lair = 17 µm, and so the real distance between the mirrors is 20 µm.

We note that because the microcavity contains both PMMA and air, the effective refractive index of the OMC region contained between the mirrors varies between neff = 1.07 for the smallest separation to neff = 1.04 for the largest gap studied because the air gap fills 85%-92% as a function of the distance between the mirrors. A change in neff can influence how deeply the EM field penetrates into the DBR’s and therefore the cavity modal volume Vm. However, changes in neff will have a negligible effect on Vm compared to the direct change in cavity volume that is brought about by changing the mirror separation.

80

For the three spectra of Figure 1, the real distances between the mirrors were 20 µm, 36 µm, 130 µm, respectively. For the case of 130 µm separation, the spectral

spacing

among

100

%T% T

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

γ=3.85 ± 0.12 meV

60

γ=3.85 µeV

40 20

cavity

resonances has decreased to the extent

0 1600

1800

2000

-1

Wavenumber(cm )

2200

Figure 2. The transmission spectrum of a thin film of PMMA spin-cast on an undoped silicon 7 substrate shows an intense absorption dip at ACS Paragon Plus Environment 1731 cm-1 with a linewidth of 3.85 ± 0.12 meV, corresponding to the stretching mode of the carbonyl bond.

The Journal of Physical Chemistry

that two of the resonances overlap with the absorption spectrum of the carbonyl stretch of the PMMA film (See Figure 2) and consequently the percent transmission through these peaks is lower. The PMMA layer, which has a pronounced absorption peak at 0.214 eV (1731 cm-1), also 100

(a) 80 60 40

Κ=2.32 ± 0.12 meV

κ=2.32 meV

20 0 1000

1500

2000

-1

2500

Normalized transmission[%]

Normalized transmission[%]

has a spectral linewidth of γ = 3.85 ± 0.12 meV (FWHM) and therefore 100

(b) 80 60 40

Κ=2.16 ± 0.12 meV

κ=2.16 meV

20 0 1000

when

(c) 80 60 40 Κ=1.98 ± 0.12 meV κ=1.98 meV

0 1000

1500

2000

-1

2500

Normalized transmission[%]

100

20

1500

2000

-1

2500

Wavenumber(cm )

Wavenumber(cm ) Normalized transmission[%]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 21

100

(d) 80 60 40 Κ=1.92 ± 0.12 meV

20

k=1.92 meV

0 1000

1500

2000

-1

2500

Wavenumber(cm )

Wavenumber(cm )

the

Figure 3. Transmission spectra for different cavity thicknesses show that cavities with larger mode density between the mirrors possess narrower cavity resonance linewidths, κ with (a-d) corresponding to different cavity separations of 20, 26, 30, and 32 µm, and cavity linewidths of κ = -1

2.32, 2.16, 1.98, and 1.92 meV, respectively, each with an error of ± 0.12 meV based on 1 cm

distance between the mirrors is 130 µm, two cavity resonances are affected by this absorption. In addition to affecting the mode density, increasing the distance between the DBR's reduced the linewidths of the cavity resonances. Figure 3 shows that for the mirror distances of 20, 26, 30, and 32 µm, the linewidth for the cavity resonance near 1700 cm-1 varied from κ = 2.32 ± 0.12 meV to 1.92 ± 0.12 meV. This is expected because the trapped photons must

8 ACS Paragon Plus Environment

Page 9 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

9 ACS Paragon Plus Environment

The Journal of Physical Chemistry

100

100

(a) 80 60 40 20 0 1500

2000

2500 -1

Normalized transmission[%]

Normalized transmission[%]

travel a greater path length and therefore their lifetime is longer. The results of Figure 3

(b) 80 60 40 20 0 1500

(c) 80 60 40 20 0 2000

-1

2500

Normalized transmission[%]

100

1500

2000

-1

2500

Wavenumber(cm )

Wavenumber(cm ) Normalized transmission[%]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 21

Wavenumber(cm )

100

(d) 80 60 40 20 0 1500

2000

2500 -1

Wavenumber(cm )

Figure 4. Normalized transmission spectra for the cavity resonantly tuned to the carbonyl transition show new polaritonic states split-off from the uncoupled vibrational energy (indicated by a vertical red dashed line), with (a-d) corresponding to the photonic mode densities of Fig. 3.

demonstrate that the OMC's DBR's are aligned and that their alignment is maintained over the range of travel of the piezoelectric stage. Thus, with a single DBR based OMC structure, it is possible to change the photon lifetime in the mid-IR spectral range in a low optical-loss cavity. When the resonance of the OMC was tuned to the absorption line of the carbonyl stretch, the spectroscopic signatures of strong light-matter coupling became manifest. Figure 4a-d shows the transmission spectra obtained for four different photonic mode densities, where in each case one of the cavity resonances was matched to the carbonyl stretch. Instead of observing a comb of 10 ACS Paragon Plus Environment

Page 11 of 21

Fabry-Perot resonances as in Figure 3, for the spectral position where the cavity resonance matched the vibrational transition, two distinct peaks were observed that were energetically splitoff from the uncoupled resonance, indicating the presence of vibrationalpolariton eigenstates. Figure 5 shows a zoom-in view of the transmission spectra of the polaritonic states in the vicinity of the resonance for the four different photonic mode densities of Figure 3 and 4. In all cases, the OMC was tuned such that the percent

Normalized transmission[%]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

8 (a) LP

6

2 0 1650

between

1700

1750

1800

-1

Wavenumber(cm )

states was nearly equal. It is seen that Rabi-splitting

UP

4

transmission through the UP and LP

the

1 2 3 4

the Figure 5. Upper and lower polariton states at normal incidence

are split-off from the uncoupled carbonyl vibrational transition

polariton states increased as the (red dashed line) for different OMC positions (1-4) distance between the mirrors was corresponding to the mirror separations of Fig. 4a-d. Smaller modal volumes shows bigger Rabi-splitting. Each of the

decreased. From Eq. 1, we see that transmission spectra have been normalized to its own peak value there are two contributions to this as done in Fig. 1-4. trend. Namely as the mirror distance decreases, the photonic mode density is reduced leading to a large vacuum electric field strength. Also, the linewidth of the cavity broadens, thereby becoming more closely matched to the linewidth of the vibrational transition. From the spectra of Figure 5, we see that the transmission amplitude of the polaritonic states is inversely proportional to distance between the mirrors.

Evidently, when the Rabi-splitting becomes

bigger, the polariton state losses are lower, perhaps due to decreased spectral overlap with the absorption spectrum of residual molecules in the microcavity that are not strongly coupled. The polariton peaks exhibit extremely narrow linewidths starting from 0.86 meV for the longer distance between the mirrors (Figure 4a-d) to 1.37 meV for the UP. The LP linewidth ranges from 1.49 meV and 1.74 meV for the same OMC positions. To confirm the formation of polariton states, we performed distance-resolved transmission measurements shown in Figure 6, for each of the cavity photon densities of Figures 3-5. To obtain the transmission spectra, the piezo actuated stage was first positioned to obtain the symmetric polariton states of Figure 5, and 11 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

then from this point, the spacing between the DBR's was adjusted in a series of several hundred nanometer moves. All detunings near the resonance condition, both positive and negative, show two prominent transmission peaks (Figure 6a-d).

The spectra of Figure 6 show clear anti-

crossing behavior which is the hallmark of microcavity polaritons. By decreasing the separation between the mirrors, the LP blueshifts approaching the uncoupled carbonyl resonance but without crossing it, and likewise, the UP blueshifts but remains at higher energy relative to the uncoupled carbonyl resonance. From the distance-resolved transmission spectra, we derived normal mode polariton dispersion relations for each of the cavity photon densities Figure 7(a-d).

12 ACS Paragon Plus Environment

Page 12 of 21

Page 13 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Using Eq. 1 to fit the dispersion, we found the Rabi-splitting to range from ℏΩR = 7.0 meV,

when the mirrors were closer (Fig 7a), to ℏΩR = 5. 9, 5.7, and 5.4 meV for larger spacing, i.e.

Fig. 7b-d respectively, each with an error of 2.5%. Hence for all data points, the collection angle is constant as is the amount of PMMA, the normal mode dispersion relations provide a clear description of

the

connection between the Rabisplitting and OMC mirror spacing. From

the

series

of

dispersion relations, we see that for smaller cavity densities, the polariton states have stronger curvature at resonance, and hence lower polaritonic effective mass. In Figure 8, the Rabisplitting parameters were plotted as a function of OMC mirror separation. The fit was generated

13 ACS Paragon Plus Environment

The Journal of Physical Chemistry

linewidths and relative vacuum

field

strengths being obtained from the

data

Figures

of 4-7.

0.230

0.225

0.220

decreases, the Rabi-splitting increases

due

to

an

improvement in

matching

between

0.210

0.205 0.208

the

linewidth and the molecular vibration of the PMMA and higher

vacuum

field

strength. the

0.212

0.216

0.220

0.224

0.230

(b) 0.225

0.220

model

0.230

(c) 0.225

0.220

ℏΩR=5.7 ± 0.14meV

0.215

0.210

0.205 0.208

0.212

0.216

0.220

0.224

ℏΩR=5.9 ± 0.15meV

0.215

0.210

0.205 0.208

0.212

0.216

0.220

0.224

Cavity Energy (eV)

Cavity Energy (eV)

cavity

From

ℏΩR=7 ± 0.18meV

0.215

As the mirror spacing

Cavity Photon UP LP UP fit LP fit

(a)

Vibration Energy (eV)

the

Vibration Energy (eV)

with

Vibration Energy (eV)

using Eq. 1,

Vibration Energy (eV)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 21

Cavity Energy (eV)

0.230

(d) 0.225

0.220

ℏΩR=5.4 ± 0.14meV

0.215

0.210

0.205 0.208

0.212

0.216

0.220

0.224

Cavity Energy (eV)

Figure 7. Upper and lower branches of normal mode polariton dispersion curves (a-d) were generated as a function of cavity tuning for the transmission spectra of Fig. 6. The dispersion relations show anti-crossing and Rabi-splitting values of ℏΩR = 7, 5.9, 5.7, and 5.4 meV, respectively, each with an error of 2.5%. The spheres are the polariton energies obtained from the peaks of the microcavity transmission spectra; the blue and red represent upper and lower branches, respectively. Solid curves correspond to theoretical fits using a twolevel coupled oscillator model and broken curves indicate the dispersion relations of the uncoupled cavity photon (dotted curve) and molecular vibration (dashed curve).

based on Eq. 1, we can predict the Rabi-splitting for larger separation of mirrors. For mirrors separation of 130 µm the predicated Rabi-splitting is 2.5 meV and this value become indiscernible relative to the linewidth of the carbonyl transition in PMMA (γ = 3.85 ± 0.12meV meV).

This upper limit explains the lack of evidence of normal mode splitting in the

transmission spectrum of Figure 1 for the cavity spacing of 130 µm, even though the cavity was near resonantly tuned to the vibrational transition. 14 ACS Paragon Plus Environment

Page 15 of 21

Rabi splitting(meV)

7.2 6.8 6.4 6.0 5.6 5.2 24

28

32

µ

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

36

40

Thickness( m) Figure 8. Rabi-splitting versus cavity thickness shows show that as the separation between the mirrors gets smaller, the Rabisplitting increases. The fit was generated using the parameters of each OMC device and Eq(1).

Conclusion In conclusion, we have demonstrated strong light-matter coupling within an OMC setup in the mid-IR spectral range. Using a low optical loss Ge/ZnS based OMC, we observed Rabi-splitting values from the carbonyl peak in PMMA ranging between 7-5.4 meV. Distance-resolved transmission spectra show clear anti-crossing between the LP and UP molecular vibrationpolariton states at room temperature. The OMC setup provides the ability to tune the microcavity resonance over a broad range and hence accurate and efficient determination of the normal mode polariton dispersion relation. The ability to tune the cavity linewidth and cavity mode volume is 15 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 21

essential for matching the cavity to generate larger Rabi-splitting relative to dephasing. OMC based polariton devices can therefore be controlled in a precise manner. With an OMC, we can tune the polariton ground state energy, which is determined by the normal mode coupling, and the degree of Rabi-splitting. These considerations and the ability to insert different materials into the cavity and couple the cavity resonance to the different molecular vibrations could be instrumental in investigating the conditions for achieving vibrational polariton Bose-Einstein Condensation.

Acknowledgments The authors greatly acknowledge financial support from the Office of Chief Scientist of Israel through a Magneton grant (No. 56432). The authors would also like to thank Nanomotion Ltd. (Yokneam, Israel) for providing the piezoelectric stage and Dr. Roman Yasinov, Mr. Gal Peled, and Dr. Nir Karasikov for their support.

References (1)

Dufferwiel, S.; Fras, F.; Trichet, A.; Walker, P. M.; Li, F.; Giriunas, L.; Makhonin, M. N.; Wilson, L. R.; Smith, J. M.; Clarke, E.; et al. Strong Exciton-Photon Coupling in Open Semiconductor Microcavities. Appl. Phys. Lett. 2014, 104, 192107.

(2)

Kasprzak, J.; Richard, M.; Kundermann, S.; Baas, a; Jeambrun, P.; Keeling, J. M. J.; Marchetti, F. M.; Szymańska, M. H.; André, R.; Staehli, J. L.; et al. Bose-Einstein Condensation of Exciton Polaritons. Nature 2006, 443, 409–414.

(3)

Deng, H. A Dynamic Condensation of Semiconductor Microcavity Polaritons. Ph.D. Thesis, Stanford University, California ,2006, 10, 21–29.

(4)

Lidzey, D. G.; Bradley, D. D. C.; Skolnick, M. S.; Virgili, T.; Walker, S.; Whittaker, D. M. Strong ExcitonPhoton Coupling in an Organic Semiconductor Microcavity. Nature 1998, 395, 53–55.

(5)

Berini, P.; De Leon, I. Surface Plasmon–Polariton Amplifiers and Lasers. Nat. Photonics 2011, 6, 16–24.

(6)

Zayats, A. V.; Smolyaninov, I. I.; Maradudin, A. A. Nano-Optics of Surface Plasmon Polaritons. Phys. Rep. 2005, 408, 131–314.

(7)

Nikolajsen, T.; Leosson, K.; Bozhevolnyi, S. I. Surface Plasmon Polariton Based Modulators and Switches Operating at Telecom Wavelengths. Appl. Phys. Lett. 2004, 85, 5833–5835.

(8)

Bozhevolnyi, S. I.; Erland, J.; Leosson, K.; Skovgaard, P. M.; Hvam, J. M. Waveguiding in Surface Plasmon Polariton Band Gap Structures. Phys. Rev. Lett. 2001, 86, 3008–3011.

16 ACS Paragon Plus Environment

Page 17 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

(9)

Hakala, T. K.; Toppari, J. J.; Kuzyk, A.; Pettersson, M.; Tikkanen, H.; Kunttu, H.; Törmä, P. Vacuum Rabi Splitting and Strong-Coupling Dynamics for Surface-Plasmon Polaritons and Rhodamine 6G Molecules. Phys. Rev. Lett. 2009, 103, 053602.

(10)

Bakker, HJ.; Hunsche, S.; Kurz, H.; J. Investigation of Anharmonic Lattice Vibrations with Coherent Phonon. Phys. Rev. B. 1994, 50, 914.

(11)

Huber, A.; Ocelic, N.; Kazantsev, D.; Hillenbrand, R. Near-Field Imaging of Mid-Infrared Surface Phonon Polariton Propagation. Appl. Phys. Lett. 2005, 87, 081103.

(12)

Muallem, M.; Palatnik, A.; Nessim, G. D.; Tischler, Y. R. Strong Light-Matter Coupling and Hybridization of Molecular Vibrations in a Low-Loss Infrared Microcavity. J. Phys. Chem. Lett. 2016, 7, 2002–2008.

(13)

Muallem, M.; Palatnik, A.; Nessim, G. D.; Tischler, Y. R. Strong Light-Matter Coupling between a Molecular Vibrational Mode in a PMMA Film and a Low-Loss Mid-IR Microcavity. Annalen der Physik. 2016, 528, 313–320.

(14)

Chovan, J.; Perakis, I. E.; Ceccarelli, S.; Lidzey, D. G. Controlling the Interactions between Polaritons and Molecular Vibrations in Strongly Coupled Organic Semiconductor Microcavities. Phys. Rev. B. 2008, 78, 045320.

(15)

Shalabney, A.; George, J.; Hutchison, J.; Pupillo, G.; Genet, C.; Ebbesen, T. W. Coherent Coupling of Molecular Resonators with a Microcavity Mode. Nat. Commun. 2015, 6, 5981.

(16)

Karabchevsky, A.; Shalabney, A. Strong Interaction of Molecular Vibrational Overtones with Near-Guided Surface Plasmon Polariton. Proc. SPIE 9899, Optical Sensing and Detection IV, 2016, 98991T.

(17)

Agrawal, A.; Singh, A.; Yazdi, S.; Singh, A.; Ong, G. K.; Bustillo, K.; Johns, R. W.; Ringe, E.; Milliron, D. J. Resonant Coupling between Molecular Vibrations and Localized Surface Plasmon Resonance of Faceted Metal Oxide Nanocrystals. Nano Lett. 2017, 17, 2611–2620.

(18)

Rodriguez, K. R.; Tian, H.; Heer, J. M.; Teeters-Kennedy, S.; Coe, J. V. Interaction of an Infrared Surface Plasmon with an Excited Molecular Vibration. J. Chem. Phys. 2007, 126, 151101.

(19)

Memmi, H.; Benson, O.; Sadofev, S.; Kalusniak, S. Strong Coupling between Surface Plasmon Polaritons and Molecular Vibrations. Phys. Rev. Lett. 2017, 118, 126802.

(20)

Porras, D.; Ciuti, C.; Baumberg, J. J.; Tejedor, C. Polariton Dynamics and Bose-Einstein Condensation in Semiconductor Microcavities. Phys. Rev. B. 2002, 66, 085304.

(21)

Lagoudakis, K. G.; Ostatnický, T.; Kavokin, a V; Rubo, Y. G.; André, R.; Deveaud-Plédran, B. Observation of Half-Quantum Vortices in an Exciton-Polariton Condensate. Science 2009, 326, 974–976.

(22)

Wertz, E.; Ferrier, L.; Solnyshkov, D. D.; Johne, R.; Sanvitto, D.; Lemaître, A.; Sagnes, I.; Grousson, R.; Kavokin, A. V.; Senellart, P.; et al. Spontaneous Formation and Optical Manipulation of Extended Polariton Condensates. Nat. Phys. 2010, 6, 860–864.

(23)

Deng, H.; Haug, H.; Yamamoto, Y. Exciton-Polariton Bose-Einstein Condensation. Rev. Mod. Phys. 2010, 82, 1489–1537.

(24)

Fainstein, A.; Jusserand, B.; ThierryMieg, V. Cavity-Polariton Mediated Resonant Raman Scattering. Phys.

17 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Rev. Lett. 1997, 78, 1576–1579. (25)

Honea, E. C.; Ogura, a; Peale, D. R.; Felix, C.; Murray, C. a; Raghavachari, K.; Sprenger, W. O.; Jarrold, M. F.; Brown, W. L. Structures and Coalescence Behavior of Size-Selected Silicon Nanoclusters Studied by Surface-Plasmon-Polariton Enhanced Raman Spectroscopy. J. Chem. Phys. 1999, 110, 12161–12172.

(26)

Brioude, A.; Lequevre, F.; Mugnier, J.; Bovier, C.; Dumas, J.; Plenet, J. C. Densification and Nanocrystallisation of Sol-Gel ZrO2 Thin Films Studied by Surface Plasmon Polariton-Assisted Raman Spectroscopy. Eur. Phys. J. B 2002, 26, 115–119.

(27)

León Hilario, L. M.; Bruchhausen, A.; Lobos, A. M.; Aligia, A. A. Theory of Polariton-Mediated Raman Scattering in Microcavities. J. Phys. Condens. Matter 2007, 19, 176210.

(28)

Yoo, H.-W. W.; Richter, L. J.; Jung, H.-T. T.; Michaels, C. a. Surface Plasmon Polariton Raman Microscopy. Vib. Spectrosc. 2012, 60, 85–91.

(29)

Hajj Hussein, R.; Pagès, O.; Firszt, F.; Marasek, A.; Paszkowicz, W.; Maillard, A.; Broch, L. Near-Forward Raman Study of a Phonon-Polariton Reinforcement Regime in the Zn(Se,S) Alloy. J. Appl. Phys. 2014, 116 083511.

(30)

Nagasawa, F.; Takase, M.; Murakoshi, K. Raman Enhancement via Polariton States Produced by Strong Coupling between a Localized Surface Plasmon and Dye Excitons at Metal Nanogaps. J. Phys. Chem. Lett. 2014, 5, 14–19.

(31)

Ding, Y. J. Investigation of Anti-Stokes Raman Processes at Phonon-Polariton Resonance: From Raman Oscillation, Frequency Upconversion to Raman Amplification. Opt. Lett. 2015, 40, 729–732.

(32)

Hutchison, J. A.; Liscio, A.; Schwartz, T.; Canaguier-Durand, A.; Genet, C.; Palermo, V.; Samorì, P.; Ebbesen, T. W. Tuning the Work-Function via Strong Coupling. Adv. Mater. 2013, 25, 2481–2485. Bhattacharya, P.; Frost, T.; Deshpande, S.; Baten, M. Z.; Hazari, A.; Das, A. Room Temperature Electrically Injected Polariton Laser. Phys. Rev. Lett. 2014, 112, 236802.

(33)

(34)

Hofling, S.; Amthor, M.; Rahimi-Iman, A.; Kim, N. Y.; Fischer, J.; Savenko, I. G.; Kulakovski, V. D.; Shelykh, I. A.; Reitzenstein, S.; Forchel, A.; et al. An Electrically Pumped Polariton Laser. IEEE Photonics Conf. 2015, 613–614.

(35)

Bhattacharya, P.; Xiao, B.; Das, A.; Bhowmick, S.; Heo, J. Solid State Electrically Injected ExcitonPolariton Laser. Phys. Rev. Lett. 2013, 110, 206403.

(36)

Das, A.; Heo, J.; Jankowski, M.; Guo, W.; Zhang, L.; Deng, H.; Bhattacharya, P. Room Temperature Ultralow Threshold GaN Nanowire Polariton Laser. Phys. Rev. Lett. 2011, 107, 066405.

(37)

Kéna-Cohen, S.; Forrest, S. R. Room-Temperature Polariton Lasing in an Organic Single-Crystal Microcavity. Nat. Photonics 2010, 4, 371–375.

(38)

Bajoni, D.; Senellart, P.; Wertz, E.; Sagnes, I.; Miard, A.; Lemaître, A.; Bloch, J. Polariton Laser Using Single Micropillar GaAs-GaAlAs Semiconductor Cavities. Phys. Rev. Lett. 2008, 100, 047401.

(39)

Baumberg, J. J.; Kavokin, A. V.; Christopoulos, S.; Grundy, A. J. D.; Butté, R.; Christmann, G.; Solnyshkov, D. D.; Malpuech, G.; Von Högersthal, G. B. H.; Feltin, E.; et al. Spontaneous Polarization

18 ACS Paragon Plus Environment

Page 18 of 21

Page 19 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Buildup in a Room-Temperature Polariton Laser. Phys. Rev. Lett. 2008, 101, 136409.

(40)

Christopoulos, S.; Von Högersthal, G. B. H.; Grundy, A. J. D.; Lagoudakis, P. G.; Kavokin, A. V.; Baumberg, J. J.; Christmann, G.; Butté, R.; Feltin, E.; Carlin, J. F.; et al. Room-Temperature Polariton Lasing in Semiconductor Microcavities. Phys. Rev. Lett. 2007, 98, 126405.

(41)

Berman, O. L.; Kezerashvili, R. Y.; Kolmakov, G. V. Harnessing the Polariton Drag Effect to Design an Electrically Controlled Optical Switch. ACS Nano 2014, 8, 10437–10447.

(42)

De Giorgi, M.; Ballarini, D.; Cancellieri, E.; Marchetti, F. M.; Szymanska, M. H.; Tejedor, C.; Cingolani, R.; Giacobino, E.; Bramati, A.; Gigli, G.; et al. Control and Ultrafast Dynamics of a Two-Fluid Polariton Switch. Phys. Rev. Lett. 2012, 109, 266407.

(43)

Antón, C.; Liew, T. C. H.; Tosi, G.; Martín, M. D.; Gao, T.; Hatzopoulos, Z.; Eldridge, P. S.; Savvidis, P. G.; Viña, L. Dynamics of a Polariton Condensate Transistor Switch. Appl. Phys. Lett. 2012, 101, 261116.

(44)

Tasolamprou, A. C.; Zografopoulos, D. C.; Kriezis, E. E. Liquid Crystal-Based Dielectric Loaded Surface Plasmon Polariton Optical Switches. J. Appl. Phys. 2011, 110, 093102.

(45)

Amo, A.; Liew, T. C. H.; Adrados, C.; Houdré, R.; Giacobino, E.; Kavokin, a. V.; Bramati, A. Exciton– Polariton Spin Switches. Nat. Photonics 2010, 4, 361–366.

(46)

Song, K.; Mazumder, P. Active Tera Hertz (THz) Spoof Surface Plasmon Polariton (SSPP) Switch Comprising the Perfect Conductor Metamaterial. IEEE Transactions on Electron Devices 2009, 56, 2792– 2799.

(47)

Jiao, B.; Yu, Y.; Dai, Y.; Hou, X.; Wu, Z. Improvement of Light Extraction in Organic Light-Emitting Diodes Using a Corrugated Microcavity. Opt. Express 2015, 23, 4055–4064.

(48)

Zhang, X.-L.; Feng, J.; Han, X.-C.; Liu, Y.-F.; Chen, Q.-D.; Song, J.-F.; Sun, H.-B. Hybrid Tamm PlasmonPolariton/Microcavity Modes for White Top-Emitting Organic Light-Emitting Devices. Optica 2015, 2, 579584.

(49)

Mazzeo, M.; Genco, A.; Gambino, S.; Ballarini, D.; Mangione, F.; Di Stefano, O.; Patanè, S.; Savasta, S.; Sanvitto, D.; Gigli, G. Ultrastrong Light-Matter Coupling in Electrically Doped Microcavity Organic Light Emitting Diodes. Appl. Phys. Lett. 2014, 104, 233303.

(50)

Christogiannis, N.; Somaschi, N.; Michetti, P.; Coles, D. M.; Savvidis, P. G.; Lagoudakis, P. G.; Lidzey, D. G. Characterizing the Electroluminescence Emission from a Strongly Coupled Organic Semiconductor Microcavity LED. Adv. Opt. Mater. 2013, 1, 503–509.

(51)

Das, A.; Xiao, B.; Bhowmick, S.; Bhattacharya, P. Polariton Emission Characteristics of a ModulationDoped Multiquantum-Well Microcavity Diode. Appl. Phys. Lett. 2012, 101, 131112.

(52)

Brodbeck, S.; Jahn, J.-P.; Rahimi-Iman, A.; Fischer, J.; Amthor, M.; Reitzenstein, S.; Kamp, M.; Schneider, C.; Höfling, S. Room Temperature Polariton Light Emitting Diode with Integrated Tunnel Junction. Opt. Express 2013, 21, 31098.

(53)

Lu, T. C.; Chen, J. R.; Lin, S. C.; Huang, S. W.; Wang, S. C.; Yamamoto, Y. Room Temperature Current Injection Polariton Light Emitting Diode with a Hybrid Microcavity. Nano Lett. 2011, 11, 2791–2795.

19 ACS Paragon Plus Environment

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

(54)

Tien, K. C.; Lin, M. S.; Lin, Y. H.; Tsai, C. H.; Shiu, M. H.; Wei, M. C.; Cheng, H. C.; Lin, C. L.; Lin, H. W.; Wu, C. C. Utilizing Surface Plasmon Polariton Mediated Energy Transfer for Tunable Double-Emitting Organic Light-Emitting Devices. Org. Electron. 2010, 11, 397–406.

(55)

Tsintzos, S. I.; Savvidis, P. G.; Deligeorgis, G.; Hatzopoulos, Z.; Pelekanos, N. T. Room Temperature GaAs Exciton-Polariton Light Emitting Diode. Appl. Phys. Lett. 2009, 94, 071109.

(56)

Tsintzos, S. I.; Pelekanos, N. T.; Konstantinidis, G.; Hatzopoulos, Z.; Savvidis, P. G. A GaAs Polariton Light-Emitting Diode Operating near Room Temperature. Nature 2008, 453, 372–375.

(57)

Yates, C. J.; Samuel, I. D. W.; Burn, P. L.; Wedge, S.; Barnes, W. L. Surface Plasmon-Polariton Mediated Emission from Phosphorescent Dendrimer Light-Emitting Diodes. Appl. Phys. Lett. 2006, 88, 161105.

(58)

Wedge, S.; Wasey, J. A. E.; Barnes, W. L.; Sage, I. Coupled Surface Plasmon-Polariton Mediated Photoluminescence from a Top-Emitting Organic Light-Emitting Structure. Appl. Phys. Lett. 2004, 85, 182– 184.

(59)

Agranovich, V.; Benisty, H.; Weisbuch, C. Organic and Inorganic Quantum Wells in a Microcavity: Frenkel-Wannier-Mott Excitons Hybridization and Energy Transformation. Solid State Commun. 1997, 102, 631–636.

(60)

Houdré, R.; Stanley, R. P.; Oesterle, U.; Ilegems, M.; Weisbuch, C. Room-Temperature Cavity Polaritons in a Semiconductor Microcavity. Phys. Rev. B 1994, 49, 16761–16764.

(61)

Kelkar, P.; Kozlov, V.; Jeon, H.; Nurmikko, A. V.; Chu, C. C.; Grillo, D. C.; Han, J.; Hua, C. G.; Gunshor, R. L. Excitons in a II-VI Semiconductor Microcavity in the Strong-Coupling Regime. Phys. Rev. B 1995, 52, 5491–5494.

(62)

Bellessa, J.; Bonnand, C.; Plenet, J. C.; Mugnier, J. Strong Coupling between Surface Plasmons and Excitons in an Organic Semiconductor. Phys. Rev. Lett. 2004, 93, 036404.

(63)

George, J.; Shalabney, A.; Hutchison, J. A.; Genet, C.; Ebbesen, T. W. Liquid-Phase Vibrational Strong Coupling. J. Phys. Chem. Lett. 2015, 6, 1027–1031.

(64)

Casey, S. R.; Sparks, J. R. Vibrational Strong Coupling of Organometallic Complexes. J. Phys. Chem. C 2016, 120, 28138–28143.

(65)

Dunkelberger, A. D.; Spann, B. T.; Fears, K. P.; Simpkins, B. S.; Owrutsky, J. C. Modified Relaxation Dynamics and Coherent Energy Exchange in Coupled Vibration-Cavity Polaritons. Nat. Commun. 2016, 7, 1–10.

(66)

George, J.; Chervy, T.; Shalabney, A.; Devaux, E.; Hiura, H. Multiple Rabi Splittings under Ultrastrong Vibrational Coupling. Phys. Rev. Lett. 2016, 117, 153601.

(67)

Shalabney, A.; George, J.; Hiura, H.; Hutchison, J. A.; Genet, C.; Hellwig, P.; Ebbesen, T. W. Enhanced Raman Scattering from Vibro-Polariton Hybrid States. Angew. Chemie - Int. Ed. 2015, 54, 7971–7975. Strashko, A.; Keeling, J. Raman Scattering with Strongly Coupled Vibron-Polaritons. Phys. Rev. A. 2016, 94, 023843.

(68)

(69)

Saurabh, P.; Mukamel, S. Two-Dimensional Infrared Spectroscopy of Vibrational Polaritons of Molecules in an Optical Cavity. The Journal of Chemical Physics. 2016, 144, 124115.

20 ACS Paragon Plus Environment

Page 20 of 21

Page 21 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

(70)

Herrera, F.; Spano, F. C. Cavity-Controlled Chemistry in Molecular Ensembles. Phys. Rev. Lett. 2016, 116, 238301.

(71)

Vergauwe, R. M. A.; George, J.; Chervy, T.; Hutchison, J. A.; Shalabney, A.; Torbeev, V. Y.; Ebbesen, T. W. Quantum Strong Coupling with Protein Vibrational Modes. J. Phys. Chem. Lett. 2016, 7, 4159–4164.

(72)

Long, J. P.; Simpkins, B. S. Coherent Coupling between a Molecular Vibration and Fabry-Perot Optical Cavity to Give Hybridized States in the Strong Coupling Limit. ACS Photonics 2015, 2, 130–136.

(73)

Greuter, L.; Starosielec, S.; Najer, D.; Ludwig, A.; Duempelmann, L.; Rohner, D.; Warburton, R. J. A Small Mode Volume Tunable Microcavity : Development and Characterization Appl. Phys. Lett. 2014, 105,121105.

(74)

Dufferwiel, S.; Li, F.; Trichet, A. A. P.; Giriunas, L.; Walker, P. M.; Farrer, I. Tunable Polaritonic Molecules in an Open Microcavity System. Appl. Phys. Lett. 2015, 107, 121105.

TOC Graphic Air

PMMA

Ge

ZnS

21 ACS Paragon Plus Environment