Passive vertical cavity surface emitting lasers

We have recently demonstrated a vertical cavity surface emitting laser (VCSEL) formed by a passive half- wavelength cavity combined with a quantum dot active region contained within a quarter-wavelength thick layer of the upper distributed Bragg reflector (DBR). This device concept enables improved performance, opportunities for innovation in the materials used to construct VCSELs, as well as allowing insertion of photonic crystals, metamaterials, or subwavelength gratings directly into the cavity region for strong interaction with the optical field, while avoiding undesirable impacts on the active region. Here we show that the thermal shift of the lasing wavelength with increase of dissipated power is reduced for the passive cavity VCSEL as compared to a conventional laser structure due to the weaker overlap between the gain region and the optical field intensity.