Abstract

The slope efficiency η_s and the output power P₀ of implant-isolated GaAlAs/GaAs vertical-cavity surface-emitting lasers (VCSELs) improve dramatically as the temperature is decreased,¹ with η_s approaching 100% at 100 K. This suggests that the VCSEL is an efficient device that is well suited for cryogenic applications, provided that its power dissipation is minimized. To achieve low power consumption P_d and high power efficiency η_eff, very low threshold current I_th and operating voltage V are also required. The former is achieved by designing the VCSEL so that optimal alignment of its lasing mode and its gain peak occurs at the desired low temperature. To reduce the operating voltages is more difficult, since the height of the energy barriers at the VCSEL mirror’s heterointerfaces become more prohibitive to carrier transport as the temperature is reduced, resulting in a large increase in V_th.¹

© 1995 Optical Society of America