Semiconductor optical gain

About: Semiconductor optical gain is a research topic. Over the lifetime, 5997 publications have been published within this topic receiving 96505 citations.

Signal mixing in a multiple input transistor laser near threshold

Abstract: A single-emitter multiple-input transistor laser has been realized and demonstrated in signal mixing, yielding in the stimulated-recombination region near laser threshold frequency conversion with simultaneously an electrical and optical output signal. In the unique nonlinear region of compression of the transistor I-V characteristics (β≡ΔIC∕ΔIB, βspon>βstim), input signals f1=2GHz and f2=2.1GHz are converted into mf1±nf2 ranging from 0.1to8.4GHz. Stimulated emission (enhanced recombination) changes the transistor into a special form of nonlinear element, a special form of electronic processor or “switch.”

Multistability in a semiconductor laser with optoelectronic feedback.

Abstract: The multistability in a single-mode distributed feedback semiconductor laser with delayed optoelectronic feedback is observed experimentally. For a given delay time, the observed dynamical state of the laser output is critically dependent on the process of varying the delay time and is limited by the range of variation. Various routes of delay time variation results in multistabilities characterized by states of different time series and power spectra.

Second harmonic generator using a laser as a fundamental wave source

Abstract: A second harmonic generator has a semiconductor laser for a fundamental wave light source. The laser includes a semiconductor laser chip and a quasi-phase matching element optically coupled together in series. The semiconductor laser chip can lase utilizing feedback of a light from the quasi-phase matching element. The quasi-phase matching element receives a laser emitted from the semiconductor laser chip and generates a second harmonic light using the laser beam as a fundamental wave light.

Optical gain of a quantum-well laser with non-Markovian relaxation and many-body effects

Abstract: In this article, a theoretical description of the optical gain of a quantum-well laser is developed taking into account non-Markovian relaxation and many-body effects. Single-particle energies are calculated using the multiband effective mass theory, and the valence-band mixing including the spin-orbit (SO) split-off band coupling is considered in the formulation. The Coulomb enhancement and the band-gap renormalization are also considered within the Hartree-Fock approximation. The gain spectra calculated with the Lorentzian line shape function show two anomalous phenomena: unnatural absorption region below the band-gap energy and mismatch of the transparency point in the gain spectra with the Fermi-level separation, the latter suggesting that the carriers and the photons are not in thermal (or quasi-) equilibrium. It is shown that the non-Markovian gain model with many-body effects removes the two anomalies associated with the Lorentzian line shape function. It is also found that the optical gain spectra depend strongly on the correlation time of the system which can be determined by the intraband frequency fluctuations.

Vertical cavity semiconductor lasers

Abstract: In a vertical cavity laser, such as an InP based vertical laser, the energy bandgap in the active region can be made equal to or larger than the bandgap in a semiconductor mirror stack by virtue of degenerate doping in the stack sufficient to suppress electronic band-to-band optical absorption. For example, the active region of an InP based laser can be lattice-matched GaInAs, GaInAsP, or a multiple quantum well structure composed of layers of InP and GaInAs--with the mirror stack composed of alternating layers of InP and degenerately doped n-type lattice-matched GaInAs or GaInAsP.