Single-mode and tunable VCSELs in the near-to mid-infrared Invited Paper

Single-mode, long-wavelength vertical-cavity surface-emitting lasers （VCSELs） in the near- to mid-infrared covering the wavelength range from 1.3 to 2.3 μm are presented. This wide spectral emission range opens applications in gas sensing and optical interconnects. All these lasers are monolithically grown in the InGaAlAs-InP material system utilizing a buried tunnel junction （BTJ） as current aperture. Fabricated with a novel high-speed design with reduced parasitics, bandwidths in excess of 10 GHz at 1.3 and 1.55 μm have been achieved. Therefore, the coarse wavelength division multiplexing （CWDM） wavelength range of 1.3 to 1.6 μm at 10 Gb/s can be accomplished with one technology. Error-free data-transmission at 10 Gb/s over a fiber link of 20 km is demonstrated. One-dimensional arrays have been fabricated with emission wavelengths addressable by current tuning. Micro-electro-mechanical system （MEMS） tunable devices provide an extended tuning range in excess of 50 nm with high spectral purity. All these devices feature continuous-wave （CW） operation with typical single-mode output powers exceeding 1 mW. The operation voltage is around 1 - 1.5 V and power consumption is as low as 10 - 20 mW. Furthermore, we have also developed VCSELs based on GaSb, targeting functionality of tunable diode laser spectroscopy （TDLS） applying a 1.84-μm VCSEL. at the wavelength range from 2.3 to 3.0 μm. The systems is shown by presenting a laser hygrometer

Polarization control and tuning efficiency of tunable vertical-cavity surface-emitting laser with internal-cavity sub-wavelength grating

We design an 850 nm tunable vertical-cavity surface-emitting laser(VCSEL)structure using an internal-cavity sub-wavelength grating.The use of such a tuning structure allows for wider wavelength tuning range and more stable single-polarization as compared to conventional tunable VCSELs.The features of the internal-cavity grating effect on the wavelength tuning and polarization characteristics of the tunable VCSEL are analyzed.The simulation results show that the largest wavelength tuning range achieves 44.2 nm,and the maximum orthogonal polarization suppression ratio(OPSR)is 33.4 dB(TE-type)and 38.7 dB(TM-type).