Recording parameters of spatially modulated coherent wavefronts

Various parameters of recording spatially modulated coherent light have been studied, with particular emphasis on the parameters related to constructing holograms. These include the ratio of the reference beam's intensity to that of the signal beam, the offset angle, the film's transfer characteristic, and the recording wavelength. Experimental results were obtained by recording interference patterns on highresolution film using the 6328-å line of the He-Ne laser. The bias level of the interference pattern was varied so as to vary the operating point on the curve representing the film's amplitude transmittance vs exposure characteristics. The percent modulation and the spatial frequency were also varied at each of the operating points. Interference patterns were recorded, using the 4880-åand 5145-å lines from the argon laser. From these data, the optimum bias level and the ratio of the signal beam to the reference beam for recording interference patterns are determined. The modulation transfer function of the film can also be determined.