12,531 research outputs found
Double active region index-guided semiconductor laser
A buried crescent InGaAsP/InP laser with a double active layer was fabricated. The laser showed very high characteristic temperature T0 and highly nonlinear light versus current characteristics. A theoretical model using a rate equation approach showed good agreement with the experimental results
Double-active-layer index-guided InGaAsP-InP laser diode
A buried crescent InGaAsP-InP laser with two active layers was fabricated to study the temperature behavior of the double-carrier-confinement structure. An anomalously high characteristic temperature T0 was measured, and optical switching behavior was observed. A mode analysis and numerical calculation using a rate equation approach explained qualitatively very well the experimental results. It was revealed that both the Auger recombination in this special double-active-layer configuration and the temperature-dependent leakage current, which leads to uniform carrier distribution in both active regions, are essential to increase T0
Thermal and Nonthermal Pion Enhancements with Chiral Symmetry Restoration
The pion production by sigma decay and its relation with chiral symmetry
restoration in a hot and dense matter are investigated in the framework of the
Nambu-Jona-Lasinio model. The decay rate for the process sigma -> 2pion to the
lowest order in a 1/N_c expansion is calculated as a function of temperature T
and chemical potential mu. The thermal and nonthermal enhancements of pions
generated by the decay before and after the freeze-out present only in the
crossover region of the chiral symmetry transition. The strongest nonthermal
enhancement is located in the vicinity of the endpoint of the first-order
transition.Comment: Latex2e, 12 pages, 8 Postscript figures, submitted to Phys. Rev.
A vertical monolithic combination of an InGaAsP/InP laser and a heterojunction bipolar transistor
A DH InGaAsP/InP mesa laser and a DH InGaAsP/InP mass-transport laser were successfully put together with an InGaAsP/InP heterojunction bipolar transistor in a vertical configuration. A laser threshold current as low as 17 mA and an output laser power of over 30 mW were achieved. Base injection current-controlled optical bistability and optical switching were demonstrated
Phase Structure of Nambu-Jona-Lasinio Model at Finite Isospin Density
In the frame of flavor SU(2) Nambu--Jona-Lasinio model with breaking
term we found that, the structure of two chiral phase transition lines does not
exist at low isospin density in real world, and the critical isospin chemical
potential for pion superfluidity is exactly the pion mass in the vacuum.Comment: 8 pages, submitted to Phys.Lett.
Combined High Power and High Frequency Operation of InGaAsP/InP Lasers at 1.3ÎŒm
A simultaneous operation of a semiconductor laser at high power and high speed was demonstrated in a buried crescent laser on a P-InP substrate. In a cavity length of 300ÎŒm, a
maximum CW power of 130mW at room temperature was obtained in a junction-up mounting configuration. A 3dB bandwidth in excess of 12GHz at an output power of 52mW was observed
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