The Introduction of Lasers into the Physical Chemistry Curriculum Joseph J. BelBruno Burke Chemistry Laboratory, Dartmouth College, Hanover, NH 03755
We have read considerable commentary regarding the need to revise our introductory and broadly targeted general chemistry courses in order to offer better education to the nonscientist and to maintain the interest of those students with a stated intention to major in the sciences. While there is a solid basis for this concern, little has been reported regarding the need also to modify the content of upper-level courses, particularly those intended for chemistry and other science majors. I t is essential that the excitement and challenge of a career in chemistry be conveyed to those who have chosen to further their study in the field. In the case of physical chemistry, a typical need is curriculum modernization so that courses better reflect the efforts of practicing chemists, both in theory and experiment. In general, this implies that we are concerned with the integration into the curriculum of such topics as lasers and computers, both in lectures and in the laboratory. Successful implementation of the relevant concepts and applications requires considerable planning, patience and persistence. The Rationale Whether or not one is in agreement with the predictions of future shortages in the number of chemists, it is clear that the number of physical chemists has been and continues to be small. Typically, students avoid a concentration in the topic due to perceptions of difficulty, but also find, based especially on their laboratory experience, that the work of a physical chemist is "boring". The problem has been described in several reports originating from NSF Study Groups in Chemistry and related fields (14).For example, in 1987, the Report of the Workshop on Physical Chemistry (I), after noting the relevance of the discipline to a wide range of other sciences, stated that
. . . it is perceived that the undergraduate physical chemistry laboraton'esare poorly equipped and do not offer the students a hands-on experience with modem instrumentation. The report went on to recommend an NSF-sponsored review of the curriculum and that special attention be paid to the equipment needs of the undergraduate laboratory The NSF-ILI program is clearly an opportunity to solve some of the problems with the laboratory, at least with regard to instrumentation purchases. Private foundations also offer financial support for the purchase ofhardware. A commitment from faculty still is required. Such commitment necessitates a considerable investment of time, a commodity in extremely short supply. However, if we are concerned and wish to make a n impact, we must be willing to invest that time and make our institutiom aware of the importance of that effort. The development of an undergraduate curriculum that integrates laser science and computer techniques is clearly one such step consistent with modernization of the curriculum and with developments in chemical research. For purposes of this opinion we concentrate on laser science and restrict computer techniques to laboratory data acquisition. Laser techniques are routinely employed in spectroscopic analysis, chemical dynamics, photochemistry, and polymer measurements in ac-
ademic, as well as, industrial settings. The NSF Report ( I ) places considerable emphasis on the utility and applicability of laser experiments in several physical chemistry subdisciplines. One goal in laboratory development should be to use this wide range of applications to expose the student in as many chemical subdisciplines as possible to modern techniques and instrumentation so as to give better education regarding the exciting and important scientific challenges they would experience if they were to choose a career in chemistry. Such laboratory experience and theoretical background also would serve them well when they move into various twes of research environments. Once students obtain experience with the instrumentation in a structured setting, it will be possible for them to undertake independent research projects with con6dence using other, more advanced laser techniques. Modernization of the laboratory will strengthen their backgrounds and maintain their interests in chemistry as the "central science".
-.
Implementation Curriculum revision is always a controversial subiect: addition of one topic to a course implies deletion of another; whether in lecture or in the laboratory, due to time constraints. An important aspect of any laboratory development is component-based exercises, so that students learn the details of the ex~erimentrather walkine t h r o u ~ ha cookbook procedure; ;.e., we should not intrgduce lasers and related equipment as "black boxes". Presenting the Theory
Lecture materials present a special challenge. Because most students will not be familiar with quantum electrodynamics concepts, any laser-theory lec&es must be based on concepts from other chemistry courses and general physics. This is clearly a major challenge. One solution to the dilemma is to present the lasers from the optical cavity point of view using elementary physics. A suitable textbook, one that pitches the material a t the correct level for the first-time student with some ~hvsicsbackeround. was published quite some time ago (4): he applicayion of these principles to problems in the chemical field is developed without extensive mathematical detail in a more recent text (5).The development of new lecture material resents several alternatives. It is possible to include as &ch material as can be squeezed into the physical chemistry sequence. An alternative is the offering of a special topics course for undergraduates. When this is not possible, an alternative for those institutions with graduate is the offering of a first-year graduate student level course or a short, introductory (one-credit)course for more senior undergraduate students. The individual department must choose the best course of action based uDon its own s~ecial situation. Finding Suitable Experiments
There are several paths one may follow in the revision of the physical chem
