Injection lasers for multichannel optical communication

Injection lasers are suitable sources of radiation for optical communication systems. The output characteristics of III-V compound and mixed crystal III-V compound injection lasers for spectral range are described. In order to improve the spectral output (and to increase the threshold for the appearance of adjacent modes) composite cavities were successfully used. Such a cavity contains the diode and a passive transparent flat plate, which serves as an additional selective component in the feedback circuit of the laser. A 96-channel telephone link was tested in the laboratory using four lasers (wavelengths 0.74, 0.78, 0.85, and 0.91μ) in one beam. The method of combining and separating the four spectral channels at the transmitter and receiver, respectively, as well as the results of the experiments are described.