The in-phase mode selection of a high-power diode laser array by a talbot cavity with an amplitude compensator

The in-phase mode selection with the amplitude compensator at a high current (I > 20 A) was analyzed theoretically and achieved experimentally in an external Talbot cavity, of length L = ZT/4. The used linear array consisted of 49 wide-aperture diodes with a diode emitter aperture a = 100 μm and a center to center period d = 200 μm. Increasing the output radiation intensity in the far-field central lobe was demonstrated, and the power of the multi-lobes was 1.57 W without the amplitude compensator and then it concentrated on the single lobe was 0.96 W by inserting the amplitude compensator in the external cavity when the injection current was 25 A. The far-field divergence of the phase locked radiation was 1.80 mrad, and the spectral FWHM of the output radiation was suppressed from 1.7 nm to 0.15 nm.