Analysis of a submicroampere laser diode

Summary form only given. Laser resonators with microscopic dimensions approaching the optical wavelength exhibit fundamentally new phenomena. Within microcavity laser diodes, reduced threshold currents are perhaps the most conspicuous token predicted for this regime. Here we discuss the operation of an oxide-confined vertical-cavity surface-emitting laser (VCSEL) featuring a submicroampere threshold current. Several measurements including polarization, linewidth, optical beam profile, and light-current characteristics confirm that the device is operating as a laser at currents less than 1 /spl mu/A. Spectroscopic and far-field measurements are used to analyze the laser´s modal structure and operation.