M. Tawfieq, J. Fricke, A. Müller, P. Della Casa, P. Ressel, A. Ginolas, H. Wenzel, B. Sumpf and G. Tränkle

Published in:

Semicond. Sci. Technol., vol. 33, no. 11, pp. 115001 (2018).

Abstract:

Passive S-bend waveguides have been thoroughly studied in the past, however active S-bend structures such as those in Y-branch distributed Bragg reflector (DBR) ridge waveguide (RW) lasers have been paid little attention. In this work, different S-bend based Y-branch DBR lasers emitting at 976 nm are developed, and their electro-optical, spectral and spatial characteristics are characterised. In total, two types of active S-bend (sinusoidal, cosinusoidal) as well as singlebend cosinusoidal Y-branch DBR-RW laser structures are investigated and their performances are compared to a reference straight DBR-RW laser. It is shown that among the investigated devices, the Cos S-bend based Y-branch laser provides the highest single-mode output power. However, when considering the spatial characteristics, the experimental results suggest that the Sin S-bend based Y-branch laser offers the best beam quality, and should be used in applications where good spatial characteristics are important. Finally, the experimental beam parameters are compared to passive waveguide simulations.

Keywords:

lasers, distributed-feedback, Bragg reflectors, diode lasers, waveguides.

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