Widely tunable 1060-nm VCSEL with high-contrast grating mirror.

We report tunable VCSELs emitting around 1060 nm, enabled by high-contrast grating (HCG) mirror. Single-mode continuous-wave (CW) operation up to 110 °C is demonstrated, with room-temperature single-mode output power >1.3 mW at a very low threshold of ~300 µA. The obtained thermal resistance of 0.88 °C/mW is low for VCSELs with an oxide-confined laser aperture. A wide, continuous tuning range up to 40 nm was achieved with electrostatic and thermal tuning, at a fast tuning speed up to 1.15 MHz. In addition, we developed transverse-mode control designs of HCGs to greatly improve the single-mode yield of oxidized VCSELs. The cost-effective, wafer-scale fabrication makes these VCSELs promising as tunable light sources for swept-source optical coherent tomography (SS-OCT) and LiDAR applications.