Integrated coherent beam combining of a laser diode mini-bar

摘要

We propose and demonstrate a coherently combined mini laser bar of six angled-grating broad-area lasers with near diffraction-limited beam quality. The combined laser system is fully integrated without any external components or feedback control. In our design, adjacent angled-grating broad-area lasers have opposite tilting angles and overlap around the facet. The coherent beam combining is obtained through the Bragg diffraction in the overlapped areas. The near diffraction-limited interference pattern in the far field shows that good spatial coherence is obtained among all six individual lasers. The optical spectra of each output aperture are measured and exhibit the same lasing wavelengths.