Prototype fiber-optical communication line with spectral multiplexing in the 1.3μ region

A prototype fiber-optical communication line with spectral multiplexing in the 1.3μ region was developed. The use of InGaAsP solid-solution heterolasers operating in the single-mode regime made possible multiplexing with a spectral interval of 10 nm at the crosstalk level of less than –20 dB. The construction of a wavelength-division multiplexer, in the form of an autocollimation system with a diffraction grating and an objective, made it possible to achieve 25-fold spectral channel multiplexing in the line.