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High peak power and brightness eye-safe lasers are desired in automotive LIDAR, for example. We address this need by developing tapered ridge waveguide lasers with highly asymmetric InGaAsP/InP epilayer emitting at around 1.5 μm wavelength. The structure allows state-of-the-art peak power of 7.3 W at 50 A current. Preliminary beam quality results indicate that the epi-design enables higher beam brightness than more traditional structures when driven with high amplitude current pulses. Results indicate that further improvements in power and brightness characteristics are possible with more optimized cavity layout and laser driver design. acceptedVersion

We report state-of-the-art results for 1180nm (narrow linewidth) laser diodes based on GaInNAs quantum wells and show results for ridge waveguide DBR laser diode including its reliability tests. Manuscript demonstrates 500 mW output power in continuous-wave operation at room temperature, wide single mode tuning region and narrow linewidth operation. Devices reached narrow linewidth operation (>250 kHz) across their operation band. acceptedVersion

High power diode laser was the first semiconductor laser used for materials processing. It has found some areas of applications in production. The most promising applications of HPDL in mechanical engineering are in thin steel sheet welding and hardening. The HDPL welding process is at this moment usually performed as conduction limited welding process. In this study the effect of joint configuration and beam properties on the efficiency of welding with HPDL were examined. Joint types tested were bead on plate and butt joint with different joint manufacture. The laser parameters tested were beam intensity, welding speed, incidence angle of laser beam and focal spot size. The tested parameters had an effect on the weld quality and the welding speed. The higher the beam intensity is the higher the welding speed can be achieved. The reliable welding parameters can be established for the welding of various industrial products.

High power diode laser (HPDL) is the newest laser tool for industrial manufacturing. The most promising areas of application of HPDL are thin sheet welding and hardening. The HPDL has several advantages and disadvantages compared to lasers CO 2 and Nd:YAG lasers currently used for welding. There is quite a few industrial applications in which diode laser is the most suitable laser. A typical industrial installation consists of a HPDL, an industrial robot, work piece manipulation and safety enclosures. The HPDL welding process is at this moment conduction limited and has therefore different parameters than the keyhole welding. In this study the basic HPDL welding parameters and the effect of the parameters on the welding process, weld quality and efficiency are examined. Joint types tested are butt joint and fillet lap joint. The parameters tested are beam intensity, welding speed, spot size, beam impingement angle. The materials tested are common carbon steel and stainless steel. By the experiments carried out it can be seen that all of these parameters have an effect on the weld quality and the absorption of the laser power during welding. The higher the beam intensity is the shorter also the throughput time is. However, in case of fillet joint the maximum welding speed and best visual out look are achieved with totally different set of parameters. Based on these experiments it can, however, be seen that reliable welding parameters can be established for the welding of various industrial products. The beam quality of the diode laser is not optimum for high speed keyhole welding but it is a flexible tool to be used for different joint types.

The high power diode laser is a new industrial tool. It has several advantages and disadvantages compared to the conventional industrially used CO2 and Nd:YAG laser. The most promising areas of application of diode laser have been considered to be thin sheet welding and hardening. Quite a few feasibility studies of the use of diode laser have been carried out in Finland. So far there has been some application in which diode laser is the most suitable laser. Typically, the HPDL is integrated to an industrial robot. The welding of stainless steel housing, car door lock and catalytic converters are typical examples of applications in which diode laser has technological as well as economical advantages over the conventional laser and welding techniques. The welding of these products requires good control over the heat input, short through put time and low investment. The weld cross-section of a diode laser weld is, because of conduction limited welding process, more suitable for these applications than the keyhole welding. Hardening of a large gear wheel presents also a good example of an application in which the diode laser makes it possible to economically produce structures that have not earlier been possible. Hardening requires a special form of heat delivery in order to ensure evenly hardened zone and acceptable quality. The application was performed with two high power diode lasers. The case studies of these four applications are presented and discussed in details in this paper.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.