From Small Lasers to Ultrathin Nonlinear Crystals

Small lasers are essential elements for the future integrated on-chip photonics, including lasers, sensors and high-volume data storage. In the first part, perovskite based small lasers (Fabry-Perot, WGM cavity) will be demonstrated. The advantages and disadvantages of perovskite serving as gain materials will be discussed. We also demonstrate the controlled growth of micro-laser array by using single layer BN as the buffer layer. On the other hand, different from the traditional very thick nonlinear crystal, we proposed that 2D Van der Waals crystal (3R MoS2) could be served as a promising ultra-thin frequency doubling crystal under the condition of phase matching. Thickness and wavelength dependent Second Harmonic Generation (SHG) spectrum of 3R MoS2 offer the selection rules of appropriate working conditions. Polarization enhancement with two petals along staggered stacking direction appears in 3R MoS2 were reported.