| 摘要 |
<p>A method for constructing an optical filter for use in a holographic scanner, includes splitting a beam (22) from a laser (20), focusing the beams so obtained on a photosensitive film (34) positioned at a predetermined distance from the laser (20), and developing the film (34). A silver-halide gelatin film or a dichromate sensitized gelatin film is used to record in one or another regions of the spectrum. The developed film acts as a holographic phase filter when reinserted at said predetermined distance, causing the beam of light emerging from the filter to have a uniform irradiance. The phase filter according to the invention is highly resistant to thermal laser damage and is comparatively cheap to produce.</p> |
