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.

Frequency-tunable semiconductor lasers

Abstract: Recent advances in frequency-tunable semiconductor lasers are reviewed. They are classified into hybrid and monolithic tunable lasers. Monolithic tunable lasers based on distributed Bragg reflector or distributed feedback laser structures are most attractive for practical applications. The device structures and the tuning characteristics are described, with emphasis on the tuning range, spectral linewidth and frequency-switching time. Recent system experiments using monolithic tunable lasers in an optical communication area are also described.

Semiconductor lasers and methods for fabricating semiconductor lasers

Abstract: An integrated semiconductor laser and light modulator includes a semiconductor laser disposed at a first region on a semiconductor substrate, a light modulator of an electric field absorbing type disposed at a second region on the semiconductor substrate adjacent to the first region for outputting a modulated light by transmitting or absorbing the laser light generated in the semiconductor laser, a semiconductor laminated layer structure including a quantum well structure layer disposed in the first region and the second region on the semiconductor substrate, and a lattice mismatched layer having a lattice constant smaller than that of the semiconductor substrate, disposed on a part of the semiconductor laminated layer structure, in the second region. It is possible to enhance the transmission efficiency of the laser light to the light modulator and the quality of the active layer of the semiconductor laser and the light absorption layer of the light modulator. Thus, an integrated semiconductor laser and light modulator that has a high reliability and long lifetime is obtained.

Far-field emission narrowing effect of microdisk lasers

Abstract: Far-field intensity distribution of semiconductor microdisk lasers is experimentally measured and the emission angle is found to be much smaller than that of a planar source with the same near-field width. In fact the emission angle is determined mainly by the disk radius instead of the disk thickness. A scalar diffraction theory in the cylindrical coordinate is developed to explain such an emission-angle-narrowing phenomenon and numerical calculation based on a vectorial diffraction theory is carried out to explain the measured polarization state.

Quantum dot photonic devices for lightwave communications

Abstract: Semiconductor quantum dots (QDs) have appealed to physicists and engineers since many years due to their ultimate carrier confinement. The new, realistic models of quantum dot lasers close to reality are based on strained heterostructures, finite barriers, many electron and hole levels, monomolecular (excitonic) recombination and non-equilibrium carrier distribution. The use of GaAs-based QDs in diode lasers and amplifiers at telecom wavelengths has been demonstrated to yield a large number of decisive advantages for systems, both from point of view of performance and of cost. For future metropolitan area networks the demand for inexpensive ultrafast amplifier is probably larger that of lasers. Semiconductor optical amplifiers (SOAs) are expected to play a decisive role here.

Statistical properties of the dynamics of semiconductor lasers with optical feedback

Abstract: We measure the time-resolved probability distribution of the light emitted by a semiconductor laser with optical feedback. We show and analyse, for the first time, high-frequency fluctuations of the laser intensity in the coherence collapse regime. Our results suggest that the noise induces the power drop-outs and the laser recovers in a deterministic fashion. We also give a new mechanism for a transition between erratic and synchronised behaviour in the laser dynamics.