Abstract

In previous work on laser diode optics, we have used laser-written phase-plates to correct the fabrication and fast-axis collimation errors of diode laser bars and produce a restoration of brightness of up to a factor of 10. Recently, we extended the technique to provide both fast-axis correction and slow-axis collimation in a single element, applied to an array of 10 tapered emitters with a 100um pitch [1]. Here we report the use of dual-axis correction for a full-length diode bar from Bookham, with 49 single mode emitters and 30W cw output at 975 nm. Fast-axis smile and lens error correction is combined with laser-cut slow axis collimation to give highly parallel beams with far-field divergence of 2.6mrad (fast axis) and 13mrad (slow-axis). Fig 1 shows the improvement in fast-axis divergence, in the form of far-field pattern vs. emitter number.

© 2009 IEEE