Abstract

While red-emitting diode lasers have been around for several decades, their use is still limited due to insufficient power or coherence. Hence, solid state lasers based on frequency conversion are still preferred for several applications (e.g. MID-IR quantum-OCT [1]). Using diode lasers would enable further micro-integration with all its benefits for decreased size and power consumption, as well as increased ruggedness and out-of-the-lab usage. Improving diode lasers to substitute solid state lasers requires to achieve spectral and spatial single mode operation with Watt level optical output power at a wavelength near 660 nm. To this end several challenges need to be addressed. To achieve single longitudinal and lateral mode operation a wavelength selective element and a spatial filter need to be introduced into the resonator. Here, we use a 10^th order distributed Bragg reflector (DBR) surface grating in an index-guided ridge waveguide (RW) section of the laser chip. However, DBR-RW lasers are limited in output power due to catastrophic optical mirror damage [2]. To overcome this, the laser chips presented here, also feature a gain-guided tapered (TP) section forming a DBR tapered laser (DBR-TPL).

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