Far-field, linewidth and thermal characteristics of a high-speed 1550-nm MEMS tunable VCSEL.

ABSTRACT

We report an electrically pumped 1550 nm MEMS tunable VCSEL with a continuous tuning of 101 nm at 22 °C. The top MEMS-DBR with built-in stress gradient within the dielectric layers is deposited in a low-temperature PECVD chamber on an InP-based half-VCSEL, structured by surface-micromachining and electrothermally actuated for continuous wavelength tuning. With 2.6 mA threshold current, the laser shows maximum CW output power of 3.2 mW at 1560 nm. The MEMS-VCSEL operates in single-mode with SMSR > 39 dB across the entire tuning range. At 36 °C, the tuning range reaches up to 107 nm. The divergence angle of the MEMS-VCSEL is approximately 5.6° for all tuning wavelengths. The intrinsic linewidth of an unpackaged device is 21 MHz. Quasi-error-free operation at 12.5 Gbps using a directly modulated MEMS-VCSEL is reported for a record 60 nm tuning, showing the potential of the so-called colorless source in WDM applications.