Numerical simulation and experiment of high brightness tapered lasers

The optical properties of a tapered laser, which can be used to improve laser beam quality and generate a high brightness optical beam, are simulated and the tapered laser is fabricated. The beam quality, the index difference, and the index difference dependence on taper angle are studied. A tapered diode laser with a ridge waveguide is introduced and formed through etching the wafer with asymmetrical waveguide structure and double quantum wells. A high brightness power is achieved due to the combination of the ridge waveguide and the taper waveguide. In the experiment, the laser delivers 978 nm, 8 W CW with an 11.96 A current. The beam quality factor M2 in the vertical and lateral directions is measured at 1.42 and 2.21, respectively.