Surface Emission Vertical Cavity Transistor Laser

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
_c
/ΔI
_B
) compression, β decreasing from 0.52 to 0.47, due to the base recombination shifting from spontaneous to stimulated with increasing base current (I
_B
>; I
_TH
). The surface emission VCTL threshold current is I
_TH
~ 3 mA for a cavity of 9×6 μm
²
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.