Versatile VCSEL source of thermal and super-thermal light

We have built highly controllable sources of thermal and super-thermal states on the basis of a single-mode (SM) and a multi-mode (MM) vertical cavity surface emitting laser (VCSEL) with noised driving current operating above the threshold. Varying the average driving current and the amplitude and bandwidth of noise, one can robustly obtain light with the temporal second-order intensity correlation function reaching 2.5 and correlation times from 1 µs to 10 ns. For the SM VCSEL, generated thermal lights retain its single-mode quality negating a need for a spectral filtering. For the MM VCSEL, one can still find a near-threshold regime when the generated thermal radiation is close to a single-mode one.