A considerable index-of-refraction modulation effect was found to occur in a negative photoresist when molecular-mass-diffusion is facilitated. This resist may then be used either as an autodeveloping indexmodulation recording material, or as a surface-modulation recording material or both, depending on the procedure utilized for recording and developing. Surface and index modulation are studied in a thin resist film by recording a 100 <i>I</i>/mm grating on it and measuring its diffraction spectrum. An approximative though simple method for analyzing this spectrum used in finding out the corresponding grating transmission phase modulation is briefly exposed.
© 1978 Optical Society of AmericaPDF Article