Investigation on photonic-corral-mode quantum ring lasers by laser scanning microscopy

Ultra low threshold microcavity lasers are ideal candidates for high-density optical interconnect light sources. Although they have been extensively studied for the last decade, muA-level electro-pumped quantum confined lasers are still under investigation. Photonic-corral-mode quantum ring (PQR) lasers with the linewidth narrower than 0.55 Aring generate micro-to-nano-ampere thresholds, and become ideal for CMOS-driven high-density emitter arrays for intra-chip optical interconnect as well as other applications such as displays. The PQR offers the following advantages for extremely high-density emitter source chip, over other semiconductor lasers presently available: a photonic quantum corral effect leads to naturally-born quantum wire behaviours for imminently recombinant carriers; the muA - nA threshold current capabilities mean kilo to mega PQR chip; radicT - dependent spectral red shifts are smaller at high operating temperatures, allowing uniform and reliable chip emission with minimal temperature sensitivities. By using laser beam induced current technique (LBIC) technique in laser scanning microscopy (LSM) we investigated the photocurrent confinement in the laser structure. The photocurrent map gives the possibility to analyze the laser structure uniformity.