Application of coherent Raman spectroscopy to the study of Raman optical activity

A spectrometer was built to study Raman optical activity, using the coherent scattering technique known as optical heterodyne detected Raman-induced Kerr effect spectroscopy. Signals were generated with a combination of an excimer pumped dye laser and single mode krypton-ion laser. The detection system consisted of a silicon PIN photodiode followed by a high frequency amplifier, boxcar integrator, and recording devices.; The spectrometer was tested by obtaining several types of nonlinear signals on a variety of materials. The optical Kerr effect (OKE) was observed using carbon disulfide, benzene, cyclohexane, water, methylene bromide and methylene iodide. Raman gain/loss, Raman-induced Kerr effect (RIKE) and optical heterodyne detected Raman-induced Kerr effect (OHD-RIKE) were observed on the 992 cm{dollar}sp{lcub}-1{rcub}{dollar} mode of benzene, and for the first time on the 174 cm{dollar}sp{lcub}-1{rcub}{dollar} mode of methylene bromide and the 128 cm{dollar}sp{lcub}-1{rcub}{dollar} and 467 cm{dollar}sp{lcub}-1{rcub}{dollar} modes of {dollar}alpha{dollar}-quartz.; The RIKE spectrometer was used primarily to study Raman optical activity (ROA) from the 128 cm{dollar}sp{lcub}-1{rcub}{dollar} mode of {dollar}alpha{dollar}-quartz. An upper limit for the third order susceptibility tensor responsible for this phenomenon has been measured. Recommendations are made for improving the sensitivity of the spectrometer for future used.; Second harmonic generation from powder samples of several new chiral polymers was observed. These materials were excited with the fundamental wavelength of Nd:YAG laser. The second harmonic intensities from these materials were compared to the intensities from some well-known standards.