Tapered laser arrays for high power operation (>1.4 W CW) at 1.59 µm for applications in surgery

The authors describe the fabrication and characterisation of high power, high brightness 1.59 µm semiconductor lasers for use in surgical applications either directly or as a pump for 2 µm wavelength Tm-doped fibre lasers. The lasers consist of a novel seven-element tapered waveguide array defined within a chip size of 1 mm × 0.5 mm. CW output powers in excess of 1.4 W at 8 A drive current have been achieved and the devices operate with single lobed far field widths of 3.5 – 4.5° FWHM.