Tunnel-junction-connected distributed-feedback vertical-cavity surface-emitting laser

An injection distributed-feedback vertical-cavity surface-emitting laser (VCSEL) with tunnel junctions served as quasi-Ohmic intercontacts (tunnel-junction-connected distributed-feedback VCSEL) is proposed. A periodic structure of vertically stacked double-heterostructure laser diodes connected by low-resistance tunnel junctions forms a vertical distributed-feedback (DFB) laser medium. To minimize the threshold, the DFB structure is placed in a Fabry-Perot cavity designed to match gain layers with the maximums of the optical mode, and the tunnel junctions-with its minimums. The passive regions with tunnel junctions provide effective vertical injection into each active region of this multiple-active-region laser. This DFB VCSEL is expected to have an improved performance, specifically, reduced threshold current and heightened output power. (C) 1998 American Institute of Physics.