Study of Laser Diode Generation in a Resonator with an External Planar Waveguide Reflector Based on the Bragg Grating

Lasing of a wide-strip (100 µm) laser diode in an external resonator based on a planar waveguide structure with the Bragg grating is experimentally studied. The waveguide structure is made on Si substrates with a SiO₂:GeO₂ waveguide layer with the contrast of 2.4%. Spectral parameters of lasing and the far-field radiation distribution are investigated as a function of the relative position of the planes of the laser diode and external planar structure waveguides. It is shown that the higher-order transverse mode dominates in the lasing, and a substantial decrease in the spectral width of the radiation and stabilization of the spectrum are observed in the entire range of operating currents. Lasing in the radiationless and emitted waveguide modes of the external planar structure is demonstrated.