Temperature-Insensitive 850-nm Dual-Mode-VCSEL With 25.1-GHz Bandwidth at 85 °C

The detuning between the spectral positions of gain peaks and cavity resonances greatly influences the elevated temperature performances of vertical-cavity surface-emitting lasers (VCSELs). Therefore, the design and optimization of gain–cavity detuning in VCSELs have long been piquing researchers' interest. This work presents an 850-nm dual-mode-VCSEL meticulously designed with qualified higher-temperature performances in mind. Bringing enhanced functionalities over extended operating temperatures, delivering 3-dB bandwidths of 27.5 GHz at 25 °C, 26.7 GHz at 65 °C, and reaching a believed to be record-breaking 85 °C bandwidth of 25.1 GHz. The 2.4-GHz bandwidth decline with the temperature rise (25 °C to 85 °C) is considerably less impaired than in prior studies. The junction temperatures and cavity lifetimes at different temperatures are extracted by fitting spectra and microwave measurements. Lastly, we summarize and discuss the critical design features and the possible future prospectives of modern high-performance uncooled datacom VCSELs with temperature-insensitive performances.