Abstract

The single straight cavity semiconductor laser has evolved into more complex cavity structures which either improve the emission property or allow versatility in operation to meet desired applications. For example, cavities with grating structures such as the Distributed Feedback Laser, produce stable single mode and with even narrower linewidth than that of the cleaved coupled cavity. A curved cavity, used in the ring laser,¹ improves optical feedback and produces polarisation independent emission. For beam scanning, a twin stripe laser² or the branding waveguide stripe injection³ have been proposed, where current injection into the two separate guides are varied to produce the beam scanning effect.

© 1995 IEEE