Temperature-Stabilized 850 nm High-Speed VCSEL With Modulation Bandwidth Over 30 GHz

We present an 850 nm vertical-cavity surface-emitting laser (VCSEL) featuring enhanced thermal stability and >30 GHz modulation bandwidth. The device maintains stable performance with bandwidths of 30.30 GHz at 25°C and 30.54 GHz at 55°C under 5 mA bias, showing minimal change. Notably, the bandwidth remains nearly constant across a wide current range (3-7 mA). The VCSEL exhibits excellent signal integrity, with relative intensity noise (RIN) consistently below -140 dB/Hz even at elevated temperatures. Advanced thermal management techniques, including polyimide integration and a double-mesa structure, effectively mitigate thermal impedance increase and carrier dynamics degradation. Furthermore, the device successfully achieves 106 Gbit/s PAM4 transmission, as evidenced by clear eye diagrams. These results demonstrate that our co-optimized thermal and carrier design represents a promising approach for developing robust optoelectronic devices capable of reliable high-temperature operation.