Cross-correlation discrimination for optical cavity modes.
Matched spatial filters were constructed for various modes of a spherical Fabry-Perot interferometer (FPSI). The cross correlation between many of these modes was obtained experimentally as well as theoretically. The orthogonality between various modes was demonstrated and used in order to discriminate against all orthogonal modes. A discrimination funtion that predicts the performance of the matched-filtering process is defined and analytically evaluated for rectangular and cylindrical Gaussian modes. It is shown that arbitrary discrimination strength can be obtained at the sacrifice of output signal strength. It was experimentally demonstrated that a scanning FPSI used in conjunction with only one zero-order-mode filter could be used over nearly its entire domain of stable cavity spacings and still maintain a full (c/2L) free spectral range.
C C
CC
Aleksoff
B D
BD
Guenther