Multimode semiconductor lasers with surface distributed feedback

Multimode semiconductor lasers with surface distributed feedback (DFB) emitting at a wavelength of 1040 nm have been developed. The DFB period is 20 $\mu$m. This design allows one to abandon the complex technological processes of two-stage epitaxy and electron lithography. For laser samples with antireflection coatings on both mirrors, a narrowing of the lasing spectrum to two competing modes located on both sides of the Bragg wavelength has been demonstrated. Its temperature stability was less than 0.1 nm/K. The presence of competing Fabry-Perot modes indicates an insufficient value of the coupling coefficient for the samples.