CONCAVE GRATING AND CONVEX MIRROR DOUBLE DISPERSION SPECTROGRAPH FOR OPTICAL NETWORK APPLICATIONS

The concave grating stationary anastigmatic spectrograph has been modi fied into a novel retroreflective scheme by introducing a convex mirro r concentric to the intermediate image. This provides double dispersio n, diffraction-limited imaging of a long entrance slit, and substantia l compensation of the stationary chromatic astigmatism. One can realiz e 140 independent multi/demultiplexers with 160 channels each simultan eously in the described device for optical network applications. Ray-t racing spot diagrams are presented. (C) 1997 Optical Society of Americ a.