All-Optical Beam Control by Forced Rayleigh Scattering

Abstract

Abstract : An analysis is presented to support the experimental efforts directed toward the achievement of all-optical beam control based upon nonlinear optical effects of thermal origin. Although Stimulated Thermal Rayleigh Scattering (STRS) is the primary effect of interest, the analysis falls in the broader category of Forced Rayleigh Scattering (FRS) where the underlying principles are the same. The interference of two coherent beams of radiation is discussed quantitatively and serves as the driving mechanism for creating a thermally- induced phase grating in an absorbing liquid, which is also discussed quantitatively. The analysis shows that for our experimental conditions, an efficient thermal phase grating can be generated using laser pulses possessing a few microjoules of energy, and is being pursued experimentally using nanosecond laser pulses. A dye laser using a grazing incidence grating (Litterman design) which was purchased for its narrower spectral linewidth and longer coherence length compared to our previous dye laser is also described.