1 Department of Photonics Engineering, Technical University of Denmark2 Nanophotonic Devices, Department of Photonics Engineering, Technical University of Denmark3 Nanophotonics Theory and Signal Processing, Department of Photonics Engineering, Technical University of Denmark
We present the first tunable vertical-cavity surface-emitting laser (VCSEL) where the top distributed Bragg reflector has been completely substituted by an air-cladded high-index-contrast subwavelength grating (HCG) mirror. In this way, an extended cavity design can be realized by reducing the reflection at the semiconductor #x2013;air interface using an anti-reflective coating (ARC). We demonstrate how the ARC can be integrated in a monolithic structure by oxidizing AlGaAs with high Al-content. The HCG VCSEL has the potential to achieve polarization stable single-mode output with high tuning efficiency. The HCG VCSEL shows a total tuning range of 16 nm around an emission wavelength of 1060 nm with 1-mW output power.
I E E E Photonics Technology Letters, 2013, Vol 25, Issue 4, p. 365-367