Single-Step Laser Plasmonic Coloration of Metal Films - ACS Applied

Subscriber access provided by UNIV OF DURHAM

Article

Single-step laser plasmonic coloration of metal films Xuewen Wang, Aleksandr Kuchmizhak, Dmitry Storozhenko, Sergey V. Makarov, and Saulius Juodkazis ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b16339 • Publication Date (Web): 18 Dec 2017 Downloaded from http://pubs.acs.org on December 19, 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.

ACS Applied Materials & Interfaces 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

ACS Applied Materials & Interfaces

Single-step laser plasmonic coloration of metal films Xuewen Wanga, Aleksandr Kuchmizhaka,b,c*, Dmitry Storozhenkoc, Sergey Makarovd, Saulius Juodkazisa,e

a

Swinburne University of Technology, John st., Hawthorn VIC 3122, Australia

b

School of Natural Sciences, Far Eastern Federal University (FEFU), 8 Sukhanova str.,

Vladivostok 690041, Russia c

Institute of Automation and Control Processes (IACP), Far Eastern Branch of Russian

Academy of Science (FEB RAS), 5 Radio Str., Vladivostok 690041, Russia d

ITMO University, Kronverkskiy prospect 49, St. Petersburg 197101, Russia.

e

Melbourne Centre for Nanofabrication, ANFF, 151 Wellington Road, Clayton, VIC 3168, Australia

*[email protected]

KEYWORDS surface coloration, direct femtosecond laser printing, nanotexturing, plasmonic nanovoids, dark-field observation, structural color.

ABSTRACT Utilization of structural colors produced by nanosized optical antennas is expected to revolutionize the current display technologies based on an ink-jet or a pigmentation-based color printing. Meanwhile, the versatile color-mapping strategy combining the fast single-step single-substrate fabrication cycle with low-cost scalable operation is still missing. We propose lithography-free pure optical approach based on a direct local ablative reshaping of the gold film with nJ-energy femtosecond laser pulses. Plasmon-color printing at a resolution up to 2.5·104

ACS Paragon Plus Environment

ACS Applied Materials & Interfaces 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

dots per inch satisfying the current visualization demands and data storage capacity is achieved. By controlling only the applied pulse energy, wide gamut of colors in scattering regime was reproduced via tuning the size of the printed nanovoids which have a polarization- and shapedependent localized plasmon-mediated scattering. Additionally, brightness of a single pixel was gradually adjusted via varying of the spacing between the printed nanovoids. The presented experimental demonstration opens a new direction toward plasmon-color printing for various applications where durability is required: low-cost cryptography, security tagging and ultracompact optical data storage.

1. INTRODUCTION Structural colors originate from a resonant interaction between light and specially designed nanoscale structures.1-9 Engineering of structural colors is a rapidly emerging research field that could have a large technological impact for durable data storage, digital displays, and optical security devices. Non-fading surface coloration with metallic gratings10,11 or hole arrays12-14 produces vivid, however, angular-dependent colors, while plasmonic15,16, all-dielectric17-20 or hybrid21,22 nanoantennas make the size of the single-color pixels comparable with the optical diffraction limit. Despite great success in plasmonic color generation achieved during last years, a low-cost fabrication technique is still required. In this sense, a high-throughput laser technology could serve as a prospective tool for plasmonic coloration becoming an industrial application facilitating reduction of the size of laser-printed pixels as required for the highest resolution.23-25 To improve resolution, tightly focused laser pulses were implemented to reshape locally the predesigned electron beam lithography (EBL)-fabricated nanoantennas via a targeted melting. This strategy recently demonstrated also for all-dielectric nanostructures20 allows to add a postprocessing scalability to the common focused ion beam (FIB) and EBL plasmonic coloration strategies21,26,27 improving the lateral resolution of the laser-printed images towards the optical 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


diffraction limit of 12.7·104 dots per inch (DPI). A bottleneck in applicability of such approach is due to a rather time-consuming, not scalable and expensive lithography methods used. In this study, we demonstrate a lithography-free single-step approach based on the direct local ablative modification of the Au film covering a silica glass substrate. We show that the reducedsymmetry plasmonic nanovoids, supporting different types of localized plasmon resonances, can be directly printed on the Au film surface at the diffraction-limited resolution. These structures serve as pixels, which resonantly scatter optical radiation reproducing different pure colors from green to red depending on their size as well as the polarization of the white-light radiation used for excitation. Adjustment of the inter-structure periodicity is demonstrated and provided the simple way to tune the brightness of the laser-printed pixels. The potential strategies to enrich the color gamut as well as to improve the printing resolution are also addressed. 2. RESULTS AND DISCUSSION Our approach conceptually illustrated in Figure 1A is based on the direct local ablative reshaping of a 50-nm-thick Au film covering glass (and silicon) substrate by using irradiation of single tightly-focused femtosecond (fs-)laser pulses. Gaussian-shape nJ-energy pulse locally melts a circularly-shaped micro-scale area on the metal film, which detaches from the underlying substrate via acoustic relaxation and resolidifies in the form of a parabola-shaped cupola. For a certain range of the applied pulse energies (see also Figure S2 in the Supporting Information), the size of the resolidified nanovoid increases gradually,28 while keeping the parabolic shape characterized by a negligible redistribution of the initial film thickness along the nanovoid circumference L (Figure 1B) as it was revealed by a detailed SEM inspection of the FIB cuts. A minimal possible separation between adjacent nanovoids was determined by printing arrays of nano-domes with a varying period and at different applied pulse energies, E. For the used focusing conditions with the diameter ~1.22λ/NA = 1.26 μm (NA=0.5 is a numerical aperture of the objective lens) at the Intensity/e2 level, the array period as small as 0.8 μm was found suitable ACS Paragon Plus Environment


to reproduce the parabola-shaped nanovoids within overall pulse energy range of E=0.8 - 1.2 nJ, while, for smaller, 0.5-μm period arrays, this range strongly decreases to 0.8 - 0.96 nJ owing to increased pulse-to-pulse overlapping (Fig. 1C), which finally resulted in breaking off the Au film.

Figure 1. Plasmonic coloration via direct local ablative reshaping of a gold film. (A) Schematic representation of the direct laser printing strategy for plasmonic coloration with adjustable single-pixel brightness. (B) Side-view (view angle of 45°) SEM images of single isolated plasmonic nanovoids printed at increased pulse energy E (upper row) on the surface of 50-nm-thick Au film. The pulse energy increases gradually from 0.8 nJ to 1.2 nJ. Bottom row demonstrates the SEM images of the central cross-sectional cuts of the similar nanovoids fabricated using FIB milling (blue lines


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


indicate the borders of the Au film). The Au film was covered with a protective 50-nm-thick Ti overlayer. Scale bar in both rows corresponds to 100 nm. (C) Series of side-view SEM images of parabola-shaped nanovoids arranged into square arrays printed with different periods. Arrays with periods of 2, 1 and 0.8 µm were printed at the constant pulse energy of 1.2 nJ, while the 500-nm period array - at 0.88 nJ. Scale bar corresponds to 500 nm.

2.1 Color control of laser nano-printing Depending on the circumference L (see Figure 1B) nanovoids show tunable resonant light scattering under a white-light dark field (DF) illumination (see Experimental section for details). Besides this expectable size-dependent character of the observed resonant light scattering from nanovoids, these structures also demonstrate pronounced variation of the optical response upon switching polarization direction of the DF radiation. Under the s-polarized irradiation, a gradual tunability of the scattering color from a pure green to orange-red is observed for the 2-µm period arrays of nanovoids (Fig. 2A; the nanovoid circumference L gradually increases from panels I to VII). A recognizable color variation and detectable changes in the corresponding back-scattering spectra are shown in Fig. 2A. Similar behavior was found under the p-polarized illumination of the arrays, however, the range of the reproduced colors as well as the color purity is weaker comparing to the s-polarized illumination case (Fig. 2B). Such pronounced polarization- and shape-dependent behavior of the backscattering signal can be understood in terms of excitation of different types of plasmon modes localized by the nanovoid curved shell. As typical reduced-symmetry hollow plasmonic nanostructures,29-32 the nanovoids can support transverse and axial types of the localized plasmon modes, while the grating-type collective resonances can also contribute the scattering spectra. For the isolated nanovoids, under s-polarized illumination, only the transverse modes can be excited,30 while for p-polarized DF



Figure 2. Optical properties of isolated nanovoids. Normalized back-scattering spectra from the Au nanovoid arrays of variable size measured under s- (A) and p-polarized (B) dark-field (DF) illumination. The period of array is 2 µm. Corresponding magnified DF images of the nanovoid arrays are also given in the insets marked as I-VII in Greek numbers. The corresponding Greek number indicates the applied pulse energy


Page 6 of 21

Page 7 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


used to produce single nanovoids within the array. Starting from 0.8 nJ/pulse for the array I, the pulse energy increases stepwise for each next array. (C) DF optical images of the large-scale (100x100 µm2) laser-textured areas containing previously presented nanovoids recorded with a 2 µm period revealing various scattering colors under s- (upper row), p- (middle row) and unpolarized side illumination (bottom). (D) Representation of the measured scattering spectra for p- (pentagons) and s-polarized (circles) side irradiation of the different nanovoid arrays on a standard CIE 1931 chromaticity diagram. (E) Hue (top), Saturation (middle) and Value (bottom) recalculated from the DF scattering spectra from the same nanovoids arrays (marked with I-VII) under their s-polarized irradiation as well as representation of scattering colors (F) from similar nanovoids under their s-polarized irradiation in the HSV color space.

irradiation both modes can affect the plasmon-mediated scattering spectra. This situation is clearly observed in the optical measurements (Figs. 2A,B), where spectral signal obtained under p-polarized illumination appears much broader indicating the contribution of different types of plasmonic modes. For transverse-type modes, the spectral position of the resonance was shown to follow simple standing-plasmon-wave model suggested in ref.31 with the following resonance conditions:

mλres =neffL,

where L is the outer circumference of the parabola-shaped nanovoid, neff is the effective refractive index of the plasmon mode excited on the air-metal film interface, m is the integer number of the half plasmon wavelengths, which fits the nanovoid circumference L. Recently, it was shown [33] that for the typical characteristic dimensions of the laser-printed nanovoids, the resonant scattering in the visible spectral range can be attributed to the m=3 transverse plasmon mode.



Nanovoids can be used for a rapid DF coloration of relatively large areas of the Au film surface (Fig. 2C). Representation of the experimentally measured DF backscattering spectra from nanovoids of variable size on the common CIE 1931 chromaticity map (Fig. 2D) shows that relatively pure scattering colors can be reproduced by tuning the nanovoid dimensions via changing the only one experimental parameter - the applied pulse energy, E. Similar analysis performed in the hue-saturation-value (HSV) color space, which provides information on the perception of colors by a human eye, reveals that all the colors reproduced via transverse-mode plasmon-mediated scattering from isolated nanovoids demonstrate the high Saturation and Value for all size range (see Figs. 2E, F).

2.2 Color performance of laser-printed arrays No significant differences in the measured DF scattering spectra were observed for the increased separation between nanovoids. This is consistent with a negligible contribution of the collective (grating) resonances for the arrays printed with the 2-μm period. However, differences appeared for the 1-µm period arrays containing nanovoids of the same size (Fig. 3A). This is apparent from the collected DF scattering signal under the p-polarized white-light illumination. Several spectral features are distinct as independent from the variation of the nanovoid size (see series of dashed curves in Fig. 3A) and can apparently be attributed to the plasmon-mediated scattering which is dominated by the collective grating-type resonances. For the s-polarized irradiation, the scattering spectra still contain all the characteristic features associated with geometrical resonances measured for isolated nanovoids (marked with the colored triangles in the Figs 3A, B)). By converting the spectral data into the dots on the CIE1931 color diagram (see Note 3 in the Supporting information), one can see that the structures printed with a smaller period reproduces similar scattering colors via direct local ablative reshaping at the same pulse energies but with twice smaller period. This also indicates a predominant contribution of the localized geometrical resonances of the


Page 8 of 21

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


Figure 3. Period-dependent optical properties of the nanovoid arrays. Normalized back-scattering spectra from the arrays of Au nanovoid printed at the gradually increased pulse energies (marked with I-VII Greek numbers) and the different periods of 1 (A) and 0.5 µm (B) measured under s- (solid) and p-polarized (dashed) dark-field illumination. Colored triangles indicate the spectral position of the geometric size-dependent resonances for isolated nanovoids. Insets show two SEM images of the nanovoid arrays printed at fixed pulse energy E=0.85 nJ as well as series of dark-field images of the nanovoid arrays. The brightness of each DF image was homogenized for better representation

isolated nanovoids to the scattering spectra for their s-polarized excitation rather than from the collective grating effect. Importantly, a similar tunability for the DF scattering colors can be reached by varying the size of the nanovoids densely packed at the 0.5-μm period under s-polarized irradiation (Fig. 3C). This indicates that even for a such small separation between neighboring nanovoids, their scattering properties are mainly governed by their geometric localized plasmon resonances under the s-polarized excitation, providing the way to increase the resolution of the laser-based color ACS Paragon Plus Environment


printing down to ~ 20000 DPI. Additional measurements were performed with a microscope objective with NA of 0.8 which provides an almost twice larger collection angle ≈106o for the light scattered by the nanovoids (see Note 4 in the Supporting information). These measurements confirm that the color tone does not depend on the directional grating artifacts. The unexpected ability to reproduce various scattering colors with the nanovoids printed at nearwavelength periodicities also can help to resolve the issue associated with the size-dependent brightness of each isolated nanovoid (compare polarization-resolved DF images in the Fig. 2A), resulting in the reduced intensity of green pixels comparing to those red. This is critically important for printing of the multi-color images. The presented coloration strategy allows for tuning the brightness of all reproduced scattering colors within the single pixel by changing the corresponding number of isolated scatterers in each pixel. This observation corresponds to the expected dependence of the scattered intensity being proportional to the volume of the scatterer. This approach is schematically illustrated in the Fig. 1A, which shows that the brightness can be adjusted via a simple increase of the number of nanovoids arranged within the single pixel having the typical size of 1.5x1.5 μm2 ( ~17000 DPI). One additional way to further reduce the characteristic size of the single pixel allowing for an augmented brightness tunability relies on the utilization of unique resonant surface structures appearing under single-pulse irradiation of the same 50-nm thick Au film at a slightly increased pulse energy (for details, see Note 1 in the Supporting information). Namely, the nanoneedle (or nanojet) containing the nanodroplet (nanoparticle) atop can deliver such functionality. Separation of the droplet from substrate is associated with the common Rayleigh-Plateau hydrodynamic instability in the molten metal material moving in the upward direction during formation.34-36 Similarly to the nanovoids, the scattering color depends mainly on the geometry variation within the nanodroplet-nanoneedle ensemble, however, the plasmon-mediated optical response is extremely sensitive to even tiny changes of the geometry (for details, see Note 5 in the Supporting information). As the lateral size of the isolated nanojet-nanoparticle structure is


Page 10 of 21

Page 11 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


smaller than 800 nm, by combining it with nanovoids it could be possible to further reduce the size of the pixel providing resolution in excess of 30000 DPI. The current pulse-to-pulse laser stability level of 0.5 % together with a compositional uniformity of polycrystalline gold films are limiting factors to print such structures in a well-controlled and reproducible manner. Since the demonstrated resolution is still several times lower than the optical diffraction limit 12.7·104 DPI, we discuss next the possible improvements. Utilization of high-NA optics for a scalable reduction of the optical focal spot size on the sample surface provides only a partial improvement and decrease of the lateral size of the nanovoid. It is associated with a strong lateral heat diffusion in the thermally thin metal film boosted by the increased heat conductivity of hot electrons during the initial two-temperature stage of relaxation.37,38 Such spreading of the molten front increases the effective size of the initial optical spot and consequently affects the lateral size of the produced nanovoid. This limits effect of optically localized excitation due to the tight focusing. Utilization of high-NA optics imposes much stricter requirements on the sample tilt alignment, crucial for fast large-scale printing. It is noteworthy that a local reshaping of the transiently molten film and its subsequent resolidification proceeds without direct ablation, thus avoiding formation and redeposition of debris on the Au film surface. Combining high ~MHz pulse repetition rates with a fast nanopositioning of the sample (or telecentric beam scanning), relatively large areas of the Au film can be covered with nanovoids at very fast printing rate using the proposed single-step procedure (for our laser setup ≈105 nanovoids per second) giving the nanotextured area the characteristic structured color under the appropriate polarization-resolved DF observation. The surface printing speed can be even further increased by using multi-beam forming lens and a downscaling on the image onto sample surface.39,40 It is clear that for Au films, the most chemically stable plasmonic material, it is impossible to reproduce all color palette, namely its violet-blue spectral region, via plasmon-mediated scattering. Utilization of Ag films demonstrating similar surface features under its local ablative



modification33 with the fs-laser pulses can add the blue colors to the demonstrated limited palette. Moreover, since the scattering colors generally depend on the plasmonic response of the metal film, materials with the specifically designed dielectric function as noble or semi-noble metallic alloys can be used to further tailor the plasmonic response via adjusting the composition of each chemical element41,42 and to reproduce various colors as we have tested for Au-Pd alloy. The limitation to produce blue color can be also solved by using the layered book-shelf geometries of thin metal films similar to a structural color of the Morpho butterfly wing, which are amenable by several optically thin layers43 or utilize semiconductor nano-spheroidal structures with strong magnetic dipole modes. Future exploration of the proposed fabrication method should investigate polarization dependence of the closely-packed arrays when interaction between single scatterers becomes significant. This provides an all-optical color switching by polarization and control of color hue by polarization of incident light.44

3 CONCLUSION AND OUTLOOK

We propose lithography-free pure optical color-mapping strategy based on direct local ablative reshaping of the thin Au film with nJ-energy fs-laser pulses. The proposed coloration approach combines fast single-step single-substrate fabrication cycle with low-cost scalable operation allowing plasmon-color printing at typical resolution up to 25000 DPI as well as tunability of the single-pixel brightness. By controlling the only experimental parameter - applied pulse energy various colors in scattering regime at diffraction-limited resolution can be reproduced via tuning the size of the parabola-shape nanovoids to involve their polarization- and shape-dependent localized plasmon-mediated scattering and adjusting the spacing between nanovoids to tune the single-pixel brightness. Various potential applications including low-cost cryptography, security tagging and ultra-compact optical data storage can be envisioned for the proposed technology.


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


4. EXPERIMENTAL SECTION 4.1 Sample preparation. The 50-nm-thick Au films were coated onto the silica glass substrates without any adhesion sublayer with a simple magnetron sputtering procedure at a chamber pressure of 10-5 and sputtering rate ~1 nm·s-1, while rotating the sample holder at a constant speed of 50 rpm to ensure an uniform film thickness over the entire sample. The actual film thickness was controlled by a build-in microbalance system and verified by the corresponding AFM measurements showing also the averaged roughness of the fabricated films less than 1 nm.

4.2 Laser plasmonic coloration. Local ablative reshaping of the 50-nm-thick Au film covering silica glass substrate was performed with second-harmonic (λ = 515 nm), 230-fs laser pulses generated by a Yb:KGW laser system (PHAROS, Light Conversion Ltd.). The laser pulses were focused into a submicrometer spot on the Au film surface using a NA=0.5 objective lens (Mitutoyo M Plan Apo NIR HR). The sample was mounted onto a PC-driven nanopositioning platform (Aerotech) allowing precise spot-by-spot laser printing of the computer-generated patterns with the movement repeatability better than 100 nm. The pulse energy was measured by a pyroelectric photodetector (Ophir) and controlled by a PC-driven attenuator.

4.3 Shape and size characterization. The fabricated arrays of the nanovoids and corresponding patterns were visualized and carefully inspected using a field-emission scanning electron microscopy (SEM) functionality of the EBL writer (Raith 150-TWO). Additional details on the nanovoid ellipticity are given in the Supporting information (Note 6). Moreover, to show detailed actual geometric dimensions of the parabola-shape nanovoids, central cross-sectional cuts of the structures printed at various pulse energies were prepared using FIB milling (Raith IonLine). For these experiments, the sample



patterned with the nanovoids was protected with a 50-nm-thick titanium over-layer to obtain clear interface contact after Ga+-ion beam slicing of nano-domes. The mechanical resistance of the laser-printed structures is also attested and presented in the Supporting information (Note 7).

4.4 Optical characterization. To characterize plasmonic response of the produced nanovoids and their arrays, polarizationresolved DF backscattering measurements were performed with a home-build confocal microspectroscopy setup (for details see Figure S1 in the Supporting information). Briefly, polarized white-light radiation from a calibrated stabilized tungsten bulb (HL2000-HP, Ocean Optics) was used to excite plasmon-mediated scattering from the laser-printed nanovoids in the sideillumination geometry at an adjustable illumination angle. The scattered signal was collected with the NA=0.5 microscope objective (Mitutoyo M Plan Apo NIR HR) coupled to a sensitive grating-type spectrometer (Shamrock 303i, Andor) equipped with a thermoelectrically cooled camera (TE-cooled CCD, Newton 971). The DF optical images were captured with a complementary metal on oxide (CMOS) camera (Nikon D5200). To avoid the contribution of the near-infrared (IR) radiation into the recorded images, the IR-cutting filter (Thorlabs FGS900M) was inserted into the camera optical path.

4.5 Color analysis of the scattering spectra. To convert the measured DF backscattering signal from nanovoid arrays into the chromaticity coordinates of a certain color space, x, y and z color-matching functions, defined by the International Commission on Illumination (CIE), were first calculated using common expressions.45 Then, the obtained (x, y and z) coordinates were converted into the data of the CIE 1931 and hue-saturation-value (HSV) color spaces using the corresponding xyz2rgb() and rgb2hsv(), which is embedded functions in Matlab Image Processing Toolbox.46


Page 14 of 21

Page 15 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


ASSOCIATED CONTENT Supporting Information Note 1. Details of dark-field back-scattering measurements Note 2. Lateral size of the produced surface structure and its scattering intensity versus applied pulse energy E. Note 3. CIE maps representation of the scattering spectra from arrays printed at various periods. Note 4. Angular dependence of the scattering signal. Note 5. Nanoneedle-nanodrop ensembles. Note 6. Ellipticity of the nanovoids. Note 7. Stability of the laser-printed structures. This material is available free of charge via the Internet at http://pubs.acs.org.

AUTHOR INFORMATION Corresponding Author *E-mail: [email protected] Notes The authors declare no competing financial interest.

ACKNOWLEDGMENTS This work was supported by the Russian Science Foundation (grant no. 17-19-01325). S.J. acknowledges the Workshop of Photonics R&D. Ltd. for the laser fabrication setup acquired via a collaborative grant and the Australian Research Council DP170100131 Discovery project. REFERENCES (1) Kumar, K.; Duan, H.; Hegde, R.; Koh, S.; Wei, J.; Yang, J. Printing colour at the optical diffraction limit. Nat. Nanotechnol. 2012, 7, 557-561. ACS Paragon Plus Environment


(2) Ai, B.; Yu, Y.; Mohwald, H.; Zhang, G. Responsive monochromatic color display based on nanovolcano arrays. Adv. Opt. Mater. 2013, 1, 724-731. (3) Olson, J.; Manjavacas, A.; Liu, L.; Chang, W.-S.; Foerster, B.; King, N. S.; Knight, M. W.; Nordlander, P.; Halas, N. J.; Link, S. Vivid, full-color aluminum plasmonic pixels. Proc. Natl. Acad. Sci. 2014, 111, 14348-14353. (4) Höjlund-Nielsen, E.; Clausen, J.; Makela, T.; Thamdrup, L. H.; Zalkovskij, M.; Nielsen, T. Pira, N.; Ahopelto, J.; Mortensen, N.A.; Kristensen, A. Plasmonic colors: toward mass production of metasurfaces. Adv. Mater. Technol. 2016, 14, 4023. (5) Gu, Y.; Zhang, L.; Yang, J.; Yeoa, S.; Qiu, C.-W. Color generation via subwavelength plasmonic nanostructures. Nanoscale 2015, 7, 6409-6419. (6) Saito K.; Tatsuma, T. Asymmetric Three‐Way Plasmonic Color Routers. Adv. Opt. Mater.

2015, 3, 883-887. (7) Kristensen, A.; Yang, J.K.W.; Bozhevolnyi, S.; Link, S.; Nordlander, P.; Halas, N.J.; Mortensen, N. A. Plasmonic colour generation. Nat. Rev. Mater. 2016, 7, 16088. (8) Duan, X.; Kamin, S.; Liu, N. Dynamic plasmonic colour display. Nat. Commun. 2017, 24, 14606. (9) B. Hwang, B.; Shin, S.-H.; Hwang, S.-H.; Jung, J.-Y.; Choi, J.-H.; Ju, B.-K.; Jeong, J.-H. Flexible Plasmonic Color Filters Fabricated via Nanotransfer Printing with Nanoimprint-Based Planarization. ACS. Appl. Mater. Interfaces 2017, 9, 27351–27356 (10) Duempelmann, L.; Casari, D.; Luu-Dinh, A.; Gallinet, B.; Novotny, L. Color rendering plasmonic aluminum substrates with angular symmetry breaking. ACS Nano 2015, 9, 1238312391. (11) Shrestha, V. ; Lee, S.-S.; Kim, E.-S.; Choi, D.-Y. Polarization-tuned dynamic color filters incorporating a dielectric-loaded aluminum nanowire array. Sci. Rep. 2015, 5, 12450. (12) Genet C.; Ebbesen, T. Light in tiny holes. Nature 2007, 445, 39-46.


Page 16 of 21

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


(13) Yokogawa, S.; Burgos, S.; Atwater, H. Plasmonic color filters for CMOS image sensor applications. Nano Lett. 2012, 12, 4349-4354. (14) Laux, E.; Genet, C.; Skauli, T.; Ebbesen, T.; Plasmonic photon sorters for spectral and polarimetric imaging. Nat. Photonics 2008, 2, 161-164. (15) Zaccaria, R. P.; Bisio, F.; Das, G. ,, Maidecchi, G.; Caminale, M.; Vu, C.D.; De Angelis, F.; Di Fabrizio, E.; Toma, A.; Canepa, M; Plasmonic color-graded nanosystems with achromatic sub-wavelength architectures for light filtering and advanced SERS detection. ACS. Appl. Mater. Interfaces 2016, 8, 8024–8031. (16)

Yang, C.; Shen, W.; Zhou, J.; Fang, X.; Zhao, D.; Zhang, X.; Ji, C.; Fang, B.; Zhang, Y.;

Liu, X., Angle robust reflection/transmission plasmonic filters using ultrathin metal patch array. Adv. Opt. Mater 2016, 4, 1981-1986. (17)

Shen, Y.; Rinnerbauer, V.; Wang, I.; Stelmakh, V.; Joannopoulos, J.; Soljacic, M.

Structural Colors from Fano Resonances. ACS Photonics 2015, 2, 27-32. (18)

Wang, L.; Kruk, S.; Tang, H.; Li, T.; Kravchenko, I.; Neshev, D. N.; Kivshar, Y.

Grayscale transparent metasurface holograms. Optica 2016, 12, 1504-1507. (19)

Vashistha, V.; Vaidya, G.; Hegde, R.; Serebryannikov, A.; Bonod, N.; Krawczyk, M. All

dielectric metasurfaces based cross shaped resonators for color pixels with extended gamut. ACS Photonics 2017, 4, 1076-1082. (20)

Zhu, X.; Yan, W.; Levy, U.; Mortensen, N.; Kristensen, A. Resonant laser printing of

structural colors on high-index dielectric metasurfaces. Sci. Adv. 2017, 3, e1602487. (21)

Zuev, D. A.; Makarov, S. V.; Mukhin, I. S.; Milichko, V. A.; Starikov, S. V.; Morozov, I.

A.; Shishkin, I. I.; Krasnok, A. E.; Belov, P. A. Fabrication of Hybrid Nanostructures via Nanoscale Laser‐Induced Reshaping for Advanced Light Manipulation. Adv. Mater. 2016, 28, 3087–3093. (22)

Ryu, S. H.; Yoon, D.K.; Switchable Plasmonic Film Using Nanoconfined Liquid

Crystals. ACS. Appl. Mater. Interfaces 2017, 9, 25057–25061.



(23)

Guay, J.-M.; Lesina, A. C.; Cote, G.; Charron, M.; Poitras, D.; Ramunno, L.; Berini, P.;

Weck, A. Laser-induced plasmonic colours on metals. Nat. Comm. 2017, 8, 16095. (24)

Robler, F.; Kunze, T.; Lasagni, A. Fabrication of diffraction based security elements

using direct laser interference patterning. Opt. Express 2017, 25, 22959-22970. (25)

Vorobyev A. Y.; Guo, C. Direct femtosecond laser surface nano/microstructuring and its

applications. Laser Photon. Rev. 2013, 7, 385-407. (26)

Zhu, X.; Vannahme, C.; Höjlund-Nielsen, E.; Mortensen, N.; Kristensen, A. Plasmonic

colour laser printing. Nat. Nanotechnol. 2016, 11, 325-329. (27)

Makarov, S. V.; Zalogina, A. S.; Tajik, M.; Zuev, D. A.; Rybin, M. V.; Kuchmizhak, A.

A.; Juodkazis, S.; Kivshar, Y. Light‐Induced Tuning and Reconfiguration of Nanophotonic Structures. Las. Photon. Rev. 2017, 11, 1700108. (28)

Wang, X.; Kuchmizhak, A.; Li, X.; Juodkazis, S.; Vitrik, O.; Kulchin, Y.; Zhakhovsky,

V.; Danilov, P.; Ionin, A.; Kudryashov, S.; Rudenko, A.; Inogamov, N. Laser-Induced Translative Hydrodynamic Mass Snapshots: Noninvasive Characterization and Predictive Modeling via Mapping at Nanoscale. Phys. Rev. Applied 2017, 8, 044016 (29)

Teperik, T.; Abajo, F. D.; Borisov, A.; Abdelsalam, M.; Bartlett, P.; Sugawara, Y.;

Baumberg, J. Omnidirectional absorption in nanostructured metal surfaces. Nat. Photonics 2008, 2, 299-301. (30)

King, N.; Li, Y.; Ayala-Orozco, C.; Brannan, T.; Nordlander, P.; Halas, N. Angle- and

Spectral-Dependent Light Scattering from Plasmonic Nanocups. ACS Nano 2011, 5, 7254-7262. (31)

Sugawara, Y.; Kelf, T.; Baumberg, J.; Abdelsalam, M.; Bartlett, P. N. Strong Coupling

between Localized Plasmons and Organic Excitons in Metal Nanovoids. Phys. Rev. B: Condens. Matter 2006, 97, 266808. (32)

Ozbay, E. Plasmonics: merging photonics and electronics at nanoscale dimensions.

Science 2006, 311, 189-193.


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


(33)

Kuchmizhak, A.; Vitrik, O.; Kulchin, Y.; Storozhenko, D.; Mayor, A.; Mirochnik, A.;

Makarov, S.; Milichko, V.; Kudryashov, S.; Zhakhovsky, V.; Inogamov, N. Laser printing of resonant plasmonic nanovoids. Nanoscale 2016, 8, 12352-12361. (34)

Kuznetsov, A. I.; Evlyukhin, A. B.; Gonsalves, M. R.; Reinhardt, C.; Koroleva, A.;

Arnedillo, M. L.; Kiyan, R.; Marti, O.; Chichkov, B. N. Laser fabrication of large-scale nanoparticle arrays for sensing applications. ACS Nano 2011, 5, 4843-4849. (35)

Unger, C.; Koch, J.; Overmeyer, L.; Chichkov, B. Time-resolved studies of femtosecond-

laser induced melt dynamics. Opt. Express 2012, 20, 24864-24872. (36)

Nakata, Y.; Miyanaga, N.; Momoo, K.; Hiromoto, T. Solid–liquid–solid process for

forming free-standing gold nanowhisker superlattice by interfering femtosecond laser irradiation. Appl. Surf. Sci. 2013, 274, 27-32. (37)

Inogamov N.; Petrov, Y. Thermal conductivity of metals with hot electrons. JETP, 2010,

110, 446-468. (38)

Petrov, Y.; Inogamov, N.; Migdal, K. Thermal conductivity and the electron-ion heat

transfer coefficient in condensed media with a strongly excited electron subsystem. JETP, 2013, 97, 20-27. (39)

Matsuo, S.; Juodkazis, S.; Misawa, H. Femtosecond laser microfabrication of periodic

structures using a microlens array. Appl. Phys. A 2005, 80, 683-685. (40)

Li, X.; Cao, Y.; Tian, N.; Fu, L.; Gu, M. Multifocal optical nanoscopy for big data

recording at 30 TB capacity and gigabits/second data rate. Optica 2015, 2, 567-570. (41)

Nishijima, Y.; Hashimoto, Y.; Seniutinas, G.; Juodkazis, Engineering gold alloys for

plasmonics. S. Appl. Phys. B 2014, 117, 641-645. (42)

Hashimoto, Y.; Seniutinas, G.; Juodkazis, S.; Balcytis, A.; Nishijima, Y. Au-Ag-Cu

nano-alloys: tailoring of permittivity. Sci. Rep. 2016, 6, 25010.



(43)

Saito, A.; Yonezawa, M.; Murase, J.; Juodkazis, S.; Mizeikis, V.; Akai-Kasaya, M.;

Kuwahara, Y. Numerical analysis on the optical role of nano-randomness on the Morpho butterfly's scale. J. Nanosci. Nanotechnol. 2011, 11, 2785-2792. (44)

Nishijima, Y.; Khurgin, J.; Rosa, L.; Fujiwara, H.; Juodkazis, S. Tunable Raman

Selectivity via Randomization of a Rectangular Pattern of Nanodisks. ACS Photonics 2014, 1, 1006-1012. (45)

Hunt R.; Pointer, M.; Measuring Colour (4th edition, Wiley) 2011.

(46)

Gonzalez, R.C.; Woods, R.E.; Eddins, S.L. Digital Image Processing Using MATLAB,

New Jersey, Prentice Hall) 2003.


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


TOC FIGURE


Single-Step Laser Plasmonic Coloration of Metal Films - ACS Applied

Recommend Documents