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Fig. 10. A photograph of the photoluminescence setup In the photoluminescence experiment, diode lasers at wavelengths of 635 nm and 785 nm are used. You must follow the safety procedures for using lasers. The diode lasers are held in a LT220P-B Collimator Tube and operated with a LD2000 APC Laser Diode Driver. The driver is contained in a unit made by the Physics Department Electronics Shop; a photograph of a laser diode with collimator, holder and driver is shown in Fig. 11. Fig. 11. Photograph of a laser diode with collimator, holder and locally fabricated driver unit. 12
1. Set up the experiment according to the schematic in Fig. 9. 2. Put on safety goggles and align the optics carefully. The PL intensity from the solution can be very weak depending on the quality of your alignment and the concentration of your solution. Use the special spanner wrench to adjust the lens in the front of the collimation tube. A cage system is used to align the lenses for collecting the light for the PL spectra. The <strong>optical</strong> axis of the cage should be perpendicular to the direction of the incident laser. For this geometry, use the cuvette holder that is designed for a PL experiment. For 785 nm infrared (IR, which is almost invisible) laser, use the IR sensitive card to check the laser spot and align the optics. (Note: as a safety measure, the laser will not be lasing if the laser head is not mounted on the laser holder.) 3. Using appropriate excitation (635 nm and/or 785 nm), record the PL spectra of both ICG and HITC-BF4 solutions with different concentrations. Acknowledgement: The original experiment design, lab guide, diagrams and photographs were prepared by Duming Zhang (c. 2005). References [1] M. O. Scully and M. Sargent, Physics Today, March 1972, p 38-47, “The concept of the photon” [2] F. Reif, Fundamentals of Statistical and Thermal Physics (McGraw-Hill, New York, 1965), pp. 373-388. [3] Daryl W. Preston, Eric R. Dietz, The Art of Experimental Physics (John Wiley & Sons, New York, 1991). [4] J. D. J. Ingle and S. R. Crouch, Spectrochemical Analysis (Prentice Hall, New Jersey, 1988) [5] M. L. J. Landsman, G. Kwant, G. A. Mook and W. G. Zijlstra, J. Appl. Physiol., 40, 575-583 (1976). “Light absorbing properties, stability, and spectral stabilization of indocyanine green”. [6] Marvin J. Weber, Handbook of Lasers (CRC Press, Boca Raton, FL, 2001). [7] Donald A. McQuarrie and John D. Simon, Physical Chemistry, a Molecular Approach (University Science Books, Sausalito, CA, 1997). 13
Page 1 and 2: OPTICS INTRODUCTION The optics lab
Page 3 and 4: explanation of the photoelectric ef
Page 5 and 6: Fig. 3. Absorptivity for tungsten a
Page 7 and 8: Photoluminescence Photoluminescence
Page 9 and 10: In Fig. 5, the tungsten lamp is ins
Page 11: silica for a wavelength range of 20

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