Correction for Losses in Optical Birefringent Networks, a Concept

摘要

The report summarizes the results of the second phase of a program on optical birefringent devices. This phase of the program has been primarily concerned with the design, construction, and testing of a narrow-band bandpass optical birefringent filter for use at 6328A. The filter is of a double-pass design, with four full-length stages and one half-length stage giving the equivalent of a nine-stage filter. Each stage consists of a 0.5 cm calcite crystal with a matched quartz compensator. The double-pass synthesis procedure of Ammann is used to calculate rotation angles for the stages which produce the desired filter characteristic. Tests were performed on the completed filter. These show that the filter has a 3 dB bandwidth of 1/4 degrees A, a usable circular aperture of 1 inch, a full angular aperture of 1.7 degrees, and a passband transmittance of 55%. The transmittance of the birefringent filter is periodic in frequency, with a passband occurring every 2A. Hence a 2A blocking filter was purchased for use in series with the birefringent filter. (Author)