Micro-Integrated External Cavity Diode Laser With 1.4-W Narrowband Emission at 445 nm

A compact external cavity diode laser module with 1.4-W narrowband emission at 445 nm is presented. A commercially available broad-area GaN-based laser diode is used as gain medium and a volume Bragg grating is integrated for wavelength stabilization. The laser module is realized on a conduction cooled package with a footprint of 25 mm × 25 mm. The spectral width is smaller than 50 pm over the whole operating range. A suppression of the amplified spontaneous emission with more than 50 dB is measured. The laser module is suitable for subsequent nonlinear frequency conversion into the deep ultraviolet spectral range.