Gasb Diode Lasers Tunable Around 2.6 Mu M Using Silicon Photonics Resonators Or External Diffractive Gratings

We report two tunable diode laser configurations emitting around 2.6 lm, where the gain is provided by a high-gain GaSb-based reflective semiconductor optical amplifier. The lasers are driven in pulsed mode at 20 degrees C, with a pulse width of 1 ls and 10% duty cycle to minimize heating effects. To demonstrate the broad tuning and high output power capability of the gain chip, an external cavity diode laser configuration based on using a ruled diffraction grating in a Littrow configuration is demonstrated. The laser shows a wide tuning range of 154 nm and a maximum average output power on the order of 10 mW at 2.63 mu m, corresponding to a peak power of 100 mW. For a more compact and robust integrated configuration, we consider an extended-cavity laser design where the feedback is provided by a silicon photonics chip acting as a reflector. In particular, the integrated tuning mechanism is based on utilizing the Vernier effect between two thermally tunable micro-ring resonators. In this case, a tuning range of around 70nm is demonstrated in a compact architecture, with an average power of 1mW, corresponding to a peak power of 10 mW. Published under license by AIP Publishing.