Abstract
In this investigation, a novel SPASER is designed and simulated which uses a forward biased pn junction to induce population inversion condition. Simulations are performed by means of SILVACO software. In the proposed structure, the active region is considered as a direct bandgap material (InGaAs) and a larger bandgap material (InP) is used for p and n regions to form heterojunctions. This pn junction is in contact with gold and surface plasmons propagate along their interface. Free space wavelength of the oscillations of surface plasmons is 1550nm that is used in photonic devices, frequently. To form the resonance cavity of the SPASER, two high reflective mirrors are placed at the ends of the plasmonic waveguide. Applied forward voltage and absorption coefficient of the SPASER are 1.2V and − 0.33cm− 1, respectively. Thus, the optical gain for a 50 microns cavity length is 1cm− 1. Moreover, the power consumption of the proposed device at these conditions is 1.2mW. The output plasmonic power is 0.6mW which yields 50% power efficiency.
Population inversion in hyperfine states of Rb with a single nanosecond chirped pulse in the framework of a four-level system
