Radial Bragg lasers (RBLs) are a class oh Photonic Crystal cavities which utilizes Bragg confinement in circular geometry to realize disk or ring cavities. The Bragg confinement mechanism allows great flexibility in engineering the radial mode profile. For example, it is possible to design a resonator in which the light is confined within a defect composed of low refractive index material or even air. By contrast, this would be impossible in the case of conventional, total-internal-reflection-based, resonators. Such configuration is useful for high power surface emitting lasers, sensing applications, optical gyroscope and more. The Bragg reflection concept allows one to tailor the reflector structure to a desired radial field profile and decouple between the modal volume (or cavity dimensions) and the radiation losses. Another unique property of RBLs is that, in contrast to conventional laser, their tendency to lase in a single mode increases with their size.
Our Group has demonstrated single mode lasing from large RBLs (100mm in diameter) utilizing InGaAs quantum wells embedded in GaAs vertical waveguide structure. The design fabrication and characterization of the RBLs are done in house using the TAU nanotechnology center facilities. Currently we are working towards realizing new compact optical gyroscope and electrically pumped broad are surface emitting lasers.
