GaAsP tunable distributed Bragg reflector laser with indium tin oxide thin-film heater

Abstract

A GaAsP quantum well tunable distributed Bragg reflector (DBR) laser with a thin-film heater above a DBR grating was designed and fabricated. As a result of the optimization of the DBR grating to obtain both high reflectivity and sharp wavelength selectivity, single-mode lasing with an output power of 54 mW and a side-mode suppression ratio of 43 dB was obtained. By forming the transparent thin-film heater at a distance of 0.1 µm above the DBR grating, the DBR grating was heated locally and efficiently, and a wide wavelength tuning range of 5.2 nm was achieved by heating with a heater power as low as 160 mW.

Novel 1064 nm DBR lasers combining active layer removal and surface gratings

“…This creates deep level traps that promote nonradiative recombination and therefore degrade the laser performance. Therefore, state-of-the-art DBR lasers emitting in the spectral region between 600 and 1200 nm are distinguished by an active layer extending over the whole cavity including the grating section [3][4][5][6][7][8][9][10]. This is possible because, first, the inter-valence band absorption is small, second, the intra-band (free carrier) absorption can be kept small by an appropriate doping profile, and third, the inter-band absorption can be saturated by optically creating electron-hole pairs.…”