Abstract

Room-temperature generation in injection heterostructure lasers with distributed Bragg reflectors (DBR) was achieved in some laboratories about two years ago [1-3]. The minimum threshold current was observed in lasers of a complicated structure with an active layer taper coupled to a more wide-gap layer with a Bragg reflector [1]. However, the threshold current remained too high for obtaining CW operation. Simplier structures of DBR heterolasers [2-4], in which the passive waveguide layer with Bragg reflectors is directly connected with the active layer, showed much worse characteristics. Recently in this DBR laser construction we have reduced the room-temperature threshold current density down to about 3 kA/cm² [5], which makes the obtaining of CW operation much easier. These results are determined by a broadening of the optical cavity and, therefore, by a decrease in the passive region absorption^*. The present talk concerns our method of preparation and certain characteristics of CW DBR heterolasers.

© 1978 Optical Society of America