The results obtained demonstrate that the lasing dynamics reflects the current dynamics formed as a result of complex nonlinear couplings within the laser-thyristor heterostructure. The observed specific features mainly result from the appearance of new channels for generation of excess carriers in the p-base. These channels enhance the main optical activation channel formed by the photogeneration due to the absorption of the spontaneous emission from the active region of the laser part of the heterostructure. The additional channels of excess carrier generation may have an optical nature in the case of scattered laser light upon appearance of new high-Q modes. For nearly critical blocked voltages, generation of carriers can be initiated by an avalanche multiplication of photogenerated carriers.

The effect of a local current turn-on in the heterostructure plane has been observed for low-voltage lasers-thyristors. It was shown that the spatial dynamics of the current-turn-on region is determined by the blocking voltage and the control current amplitude. For the first mode (blocking voltages up to 15 V), the current nonuniformity in the heterostructure plane is determined by the flux distribution of the spontaneous emission from the active region in the laser part to the side of the p-base of the phototransistor part of the heterostructure. The transition to the second mode (blocking voltages exceeding 15 V) is due to the sharp rise in the generation rate of excess carriers in the p-base of the phototransistor part of the heterostructure. In this case, the size of the region in which the original current turn-on occurs decreases to 70 μm. It was found that the rate at which the current-turn-on region expands depends on the working conditions of the laser part of the laser-thyristor and is 50 and 20 μm/ns for the spontaneous generation and lasing modes, respectively. It was also found that the spatial dynamics of the current determines the spatial dynamics of the laser light turn-on in the lateral waveguide and the emission efficiency in generation of short (<10 ns) laser pulses. It was demonstrated that, at low control currents, the main contribution to the decrease in the emission efficiency is made by the residual optical loss in the turned-off part of the laser-thyristor. At higher amplitudes of the control current, the emission efficiency grows due to the decrease in the residual loss in the turned-off part of the laser-thyristor, which made it possible to raise the peak power to 47 W for 100-ns laser pulses.

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This letter shows an experimentally studied approach that increases injection efficiency of high-power laser thyristors emitting in the 890-910 nm spectral band. The developed laser thyristors exhibit 43-W maximum peak output power of laser pulses at 95-nm full width at half maximum duration. At the same time, the maximum amplitude of the current pulse generated in the laser-thyristor circuit reached 90 A.Index Terms-Laser-thyristor, semiconductor laser, thyristor heterostructure.