Experimental investigation of dynamic characteristics of injection lasers

An experimental method was developed for the study of dynamics of the establishment of the spectral, power, and spatial characteristics of the radiation emitted by injection lasers with good spectral (~0.1 nm), temporal (~2×10^–10 sec), and spatial (~1 μ) resolutions. An investigation was made of few-mode injection lasers based on Al_xGa_1–xAs–GaAs heterostructures of two types. The characteristic time for the establishment of the half-width of the emission spectrum was τ_s ≤ 5×10^–10 sec. It was also found that in the case of injection lasers characterized by an instability of the lasing channel the changes in the spectrum due to this instability occurred in a time τ_i ≤ 2×10^–10 sec. The characteristics of these injection lasers were studied when the pump current pulses had a microwave component of frequency in the range 0.1–3 GHz. It was found that for f ≤ 1/2πτ_s, the influence of the microwave component on the emission spectra of the injection lasers was slight. However, when the pump pulse included a microwave component and the frequency of this component was 2πfτ_i > 1, the emission from lasers with a kink-type instability depended strongly on the initial conditions.