Surface Emission Vertical Cavity Transistor Laser

Abstract

We demonstrate the first surface emission vertical cavity transistor laser (VCTL) operation with an InGaP heterojunction bipolar transistor incorporating the InGaAs quantum-wells in the base and vertical distributed Bragg reflectors. The transistor collector I-V characteristics show gain (β = ΔI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> /ΔI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> ) compression, β decreasing from 0.52 to 0.47, due to the base recombination shifting from spontaneous to stimulated with increasing base current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> >; I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</sub> ). The surface emission VCTL threshold current is I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</sub> ~ 3 mA for a cavity of 9×6 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> lateral dimensions. The laser spectra at IB = 10 mA exhibit two peaks at 975.12 and 975.22 nm with linewidth Δλ ~ 0.7 Å.