Coherent Transmission using an External Waveguide Bragg Reflector Laser with Direct Frequency Modulation.
01 January 1987
Single frequency 1.5micron semiconductor laser, formed by butt coupling of a regular Fabry-Perot laser to an external waveguide Bragg reflector, is shown to have very uniform frequency modulation characteristics under direct current modulation. The lasers frequency modulation characteristics together with its narrow linewidth ( ~ 1 MHz), makes coherent transmission possible without external modulators. The laser performance was evaluated in a 417 Mbit/s, 102 km, frequency shift keying coherent transmission experiment.