Blue High‐Power Laser Diodes ‐‐ Beam Sources for Novel Applications

Abstract

AbstractHigh‐power diode lasers are possibly the most efficient way of making electrical energy usable for material processing, like welding, cutting, soldering or other high‐power applications. While IR laser were invented over fifty years ago and have been used in industry for more than two decades, GaN high‐power lasers have only recently been used for material processing, especially for welding and soldering of copper. Although the blue wavelength offers unique and undisputable advantages over IR for the latter application, some difficulties still had to be overcome. Here is an overview of the development steps of GaN lasers from their commercial beginnings as a 1 mW light source in Blue‐ray players to today's 1.5 kW system. Also, important investigations to reach power efficiencies of 40 % will be explained as well as considerations to reach lifetimes of 65 khr and longer. We also venture a prediction of future developments based on a comparison to IR laser diodes.