A. Stavdas et al., DESIGN AND PERFORMANCE OF CONCAVE HOLOGRAPHIC GRATINGS FOR APPLICATIONS AS MULTIPLEXERS DEMULTIPLEXERS FOR WAVELENGTH ROUTED OPTICAL NETWORKS/, Optical engineering, 35(10), 1996, pp. 2816-2823
The design method and the performance of two types of concave gratings
for operation as multiplexers/demultiplexers, with 10 nm/mm reciproca
l linear dispersion, required to multiplex/demultiplex channels separa
ted by 0.5 nm in wavelength, are presented. The first type of grating
is designed in such a way that the principal ray of the central wavele
ngth in the spectrum is diffracted at normal angles to the image field
. The second type of grating is a Rowland circle mount. In each case,
two recording configurations are obtained. The performances of the mou
nts are almost identical. In the first configuration, the coupling los
s is less than -2.7 dB and the optical isolation is better than -37 dB
. In the second configuration, the losses are less than -1.8 dB and th
e optical isolation is better than -43 dB. Finally, a Rowland circle g
rating with 4 nm/mm reciprocal linear dispersion, which can multiplex/
demultiplex at least 175 channels with loss less than -2.6 dB and cros
stalk better than -28 dB, is presented. These spectrographs can be use
d for wavelength routing applications in wavelength division multiplex
ing (WDM) networks. (C) 1996 Society of Photo-Optical Instrumentation
Engineers.