Collector breakdown in the heterojunction bipolar transistor laser

摘要

Data are presented on a quantum-well (QW)-based InGaP/GaAs/InGaAs (QW) heterojunction bipolar transistor laser modified with external (increased) mirror reflection yielding lower threshold current (I_B=23 → 19 mA) and higher collector breakdown voltage ( ≥ 2.5 V). Increased breakdown at lower currents is observed on the collector Ⅰ-Ⅴ characteristics, at constant base current I_B, as a slope change, a comer, and a narrow-line to broadband spectral shift from stimulated (high coherent optical field) to spontaneous (lower incoherent field) operation, a consequence of quenching or reducing photon-assisted tunneling (Franz-Keldysh effect) under the constraint I_E+I_B+I_c=0 as α → 1(α ≡ ΔI_C/ΔI_E).