Properties of wavelength tunable VCSELs with MEMS cantilever

As one of the most rapidly growing areas of the tunable semiconductor diodes, tunable vertical cavity surface-emitting lasers (VCSELs) have been focused on and the wavelength tuning characteristics have been investigated in detail. By applying an electrostatic bias between the semiconductor and the cantilever which is an external reflector apart from the device, the stimulated wavelength can be continuously modulated with a continuous tuning over a 10nm spectral range. It is found that, as the tunable VCSEL operate in its stable regime, the displacement of the cantilever will result in a periodic variation in the intensity and wavelength with a period of half the resonant wavelength. We also found the same phenomenon in the tunable RCLED. In addition, based on our observations, precise analysis is presented from the Lang and Kobayashi model. Our results show an adequate match between theory and experiments for the detailed tunable spectra. These results can be used to greatly enhance the performance of tunable VCSEL and RCLED.