Optimization of planar Be-doped InGaAs VCSEL's with two-sided output

Abstract

Threshold current, output power, wall-plug efficiency and operating voltage of epitaxially grown InGaAs-AlGaAs planar vertical-cavity surface-emitting lasers (VCSEL's) are strongly influenced by the electrical and optical properties of the p-doped Bragg reflector. Here we study in some detail the dependence of output behavior on the composition, interface grading, and modulation doping of the Be-doped AlGaAs-GaAs Bragg reflector. Using optimized p-doped mirrors VCSEL's with low threshold current densities of 300 A/cm/sup 2/, low driving voltages of 1.6 V and high wall-plug efficiencies of 17.6% are obtained. Transverse single-mode emitting devices show a record low emission linewidth of 30 MHz and a linewidth-power product of 2.2 mW/spl middot/MHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>