Threshold temperature dependence of subnanosecond optically excited 1.3-μm InGaAsP lasers

Abstract

We report the first measurement of the temperature dependence of the relative threshold carrier density, Nth, in InGaAsP-InP lasers. The characteristic temperature T′0, defined by 1/T0 ≡d ln Nth/dT, which is independent of nonradiative recombination mechanisms, is determined by transient pumping of a simple double heterostructure laser with optical pulses short (≂100 ps) compared to the carrier lifetime (2–3 ns). A single T′0 as large as 120 K describes an exponential threshold dependence on temperature over a wide temperature range (160–370 K). Comparison with steady state (300 ns) excitation of the same samples shows that nonradiative recombination is responsible for the commonly observed injection laser break from a low-temperature T0≂100 K to the poorer room-temperature T0≂65 K. The measured T0 is smaller than a previously calculated value of approximately 200 K.