High-speed digital modulation of ultralow threshold (w i t h o u t bias

Abstract

GaAlAs buried heterostructure lasers with submilliampere threshold current fabricated from single quantum well wafers can be driven directly with logic level signals without any current bias. The switch‐on delay was measured to be <50 ps and no relaxation oscillation ringing was observed. These lasers permit fully on‐off multigigabit digital switching while at the same time obviating the need for bias monitoring and feedback control.