Response curve for photosensitive films: a derivative method

Abstract

A derivative technique is developed for measuring the material response of photosensitive films. The method consists of recording a low modulated grating superimposed with different uniform preexposures. The modulation of the resulting shallow gratings recorded on the photosensitive film is measured by diffraction techniques and the derivative response is thus computed. Compared with other diffraction-based methods, this one is not affected by nonlinearities. Qualitative visual monitoring of these diffraction data may be used for optimizing materials and processes in photolithography and optical recording. Some experimental results concerning positive and negative photoresists are presented.

Optical recording mechanisms in undoped titanosillenite crystals

“…The recording of spatially periodic structures ͑gratings͒ is used since long [1][2][3] for photosensitive materials characterization. The use of holography for producing such structures for characterizing index and/or absorption coefficient changes in photosensitive materials [4][5][6] has clear advantages over other techniques because of its noncontact nature, feasibility of spatial period selection, and simplicity of measurements.…”