4 March 2015 Extraction and analysis of high-frequency response and impedance of 980-nm VCSELs as a function of temperature and oxide aperture diameter
Author Affiliations +
Abstract
Vertical-cavity surface-emitting lasers (VCSELs) are decisive cost-effective, energy-efficient, and reliable light sources for short-reach (up to ~300 m) optical interconnects in data centers and supercomputers. To viably replace copper interconnects and advance to on-chip integrated photonics, reliable VCSELs ideally must be able to operate highly energy efficient, but at large bit rates and without cooling up to 85 °C, with immunity to temperature variations. Our 980 nm VCSELs achieve such temperature-stable, energy-efficient, and high-speed operation coincidently. Record low 139 fJ/bit of dissipated heat for 35 Gbit/s error-free data transmission at 85 °C is reported. Careful design of both the VCSEL’s epitaxial structure and device geometry is of essence. Introducing a suitable gain-to-etalon wavelength offset simultaneously improves the temperature-stability, the maximum bit rate at high temperatures, and the energy efficiency. Tuning the photon lifetime additionally increases the bandwidth by changing the relation between damping and resonance relaxation frequency. Systematic temperature-dependent and oxide aperture-diameter-dependent measurements, including static L-I-V curves and emission spectra, small signal analysis, and data transmission experiments are reported. The modulation bandwidth, the parasitic cut-off frequency, the relaxation resonance frequency, lumped-circuit elements, and the K- and D-factors are derived, useful for energy-efficient optical interconnects based on 980 nm VCSELs.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Philip Wolf, Hui Li, Philip Moser, Gunter Larisch, James A. Lott, Dieter Bimberg, "Extraction and analysis of high-frequency response and impedance of 980-nm VCSELs as a function of temperature and oxide aperture diameter", Proc. SPIE 9381, Vertical-Cavity Surface-Emitting Lasers XIX, 93810H (4 March 2015); doi: 10.1117/12.2077182; https://doi.org/10.1117/12.2077182
PROCEEDINGS
8 PAGES


SHARE
RELATED CONTENT


Back to Top