Carrier lifetime measurement of a junction laser using direct modulation

A carrier lifetime measurement under lasing conditions using microwave techniques is reported. The direct modulation characteristic of a junction laser is analyzed, based on the rate equations, and a resonance-like phenomenon of the modulated output is calculated at a fixed frequency determined by the parameters of the junction diode. This frequency occurs just before the modulation cutoff frequency of the diode. The minority carrier lifetime in the active region of the junction laser is expressed in terms of this frequency and other parameters. A modulation experiment was performed using a microwave frequency modulated bias pulse current. The resonance-like phenomenon was confirmed experimentally and the carrier lifetime was determined from the analysis presented here.