Holographie en infrarouge sur de minces couches d'huile

Albumen as a relief recording media for spatial distributions of infrared radiation. Fabrication of interference gratings and microlenses

It is shown that a relief is generated when spatial distributions of infrared light (lambda = 10.6 microm) are recorded on albumen films. The relief can be applied to the fabrication of microelements, such as diffraction gratings and microlenses. Examples are shown.

Lateral shear interferometer for infrared and visible light

An infrared wavefront is recorded holographically on a dynamic recording medium consisting of a thin oil film on a glass substrate. The phase hologram obtained may restore the information of the infrared wavefront or alternatively play the role of a diffraction grating for a visible reconstruction beam. On this basis, the principle of a lateral shear interferometer for the simultaneous testing of infrared or visible optical components is described and physically implemented. A theoretical discussion explains the operation of the interferometer and points out experimental restrictions due to recording medium nonuniformities, holographic aberrations, and the curvature of the reconstructed wavefronts. The interferometer is easy to set up and confirms its usefulness with experimental results that include collimation tests for both visible and infrared afocal assembly, as well as quality tests for visible components.

Infrared laser photography with silver-halide emulsion

Infrared sensitization of photographic emulsion response to visible light is a useful technique for visualizing IR laser beams. In this work, it is demonstrated that this sensitization results from heating by the IR beam. Investigation of the dependence of sensitization by pulsed CO(2) laser (10.6-microm) preexposures on visible background density, IR fluence, visible wavelength, delay between exposures, and spatial frequency are described. Infrared fluences as low as 10 mJ/cm(2), a dynamic range greater than 100, and a resolution better than 50 lines/mm were observed. Suggestions for further improvements of the technique are made.