Spectrally stabilized high-power high-brightness DBR-tapered lasers in the VIS and NIR range

摘要

A promising concept to achieve high-output power together with a narrow spectral line-width and a diffraction limited beam quality is the use of tapered diode lasers consisting of a distributed Bragg reflector (DBR) mirror as rear side wavelength selective mirror. The DBR mirror provides high reflectivity for the selected emission wavelength and besides contributes to spatial mode filtering. A ridge waveguide (RW) section supports the fundamental lateral mode suppressing higher order modes and the tapered gain region is used for amplification. The taper angle had to be designed with respect to the properties of the RW section. The implementation of separate electrical contacts allows a flexible output power together with fundamental mode operation. In this work, high brightness DBR tapered diode lasers with separate electrical contacts for the wavelength range between 630 nm and 1180 nm will be presented. For red emitting devices, around 637 nm an output power up to about 1 W is achieved, limited by the properties of the semiconductor material. Devices emitting in the longer wavelength range around 1000 nm reach output powers up to 15 W. For all the above manufactured diode lasers about 80% of the emitted laser light is within the diffraction limited central lobe. Here, e.g. 10 W diffraction limited power was measured. The devices are successfully implemented into experiments for non-linear frequency conversion, e.g. SHG and the pumping of an OPO, as an excitation source for absorption spectroscopy, as pump source for fs-lasers, and their emission is efficiently coupled into single mode fibers.