Time-resolved spectral output of pulsed GaAs lasers

When pulse operated, all injection lasers show a laser line shift which is linear with time during the pulse length. This is evident for time-resolved spectra obtained by a scanning technique. The data present time-resolved spectra for pulse-operated gallium arsenide laser diodes. At high peak current values, joule heating results and the time-resolved laser spectra are seen to shift to longer wavelengths. A line-shift coefficient is defined for which the units are angstroms per (ampere)²per microsecond. For high peak current and long pulse length, the laser lines may shift one hundred angstroms or more.