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Showing 1 to 20 of 46 for “"threshold current."”.
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Threshold current and modulation response of semiconductor lasers
… in the region), and the resulting effect on the threshold current is examined. The investigations are performed with a simple rate equation simulator, as well as with a self-consistent laser simulator MINILASE. The models predict similar qualitative trends in threshold current dependencies.
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Improving the efficiency and threshold current of photonic crystal vertical-cavity surface-emitting lasers
… work focuses on how to achieve high power, low threshold, and high efficiency single mode VCSELs. Various mechanisms that affect the differential quantum efficiency and threshold current of the proton-implanted and oxide-confined photonic crystal vertical-cavity surface-emitting lasers (VCSELs) …
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Design, Fabrication, and Characterization of Terahertz Quantum Cascade Lasers
… finite element modeling (FEM) to determine the threshold material gain coefficient and compare it to the experimental results of the threshold current density. We find that the threshold current density is roughly constant until the substrate thickness becomes smaller than 150 microm.
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Simulation, Fabrication, and Characterization of Semiconductor Lasers
… thus providing passive modelocking. The measured threshold current for BAL is around 140 mA whereas it is 26 mA and 36 mA for ridge waveguide and passively mode locked laser respectively for 1 mm cavity length. The threshold current density is also calculated 139.91 A/cm2 for infinite cavity …
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Vertical -Cavity Surface -Emitting Lasers Operating in Photonic Crystal Waveguide Defect Modes
… optimized to give maximum output power and lower threshold current, the role of loss in improving modal properties is investigated, and high speed operation is characterized. Optimized lasers exhibit sub-milliamp threshold current and operate in the fundamental lateral mode for all currents.
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Semiconductor quantum dot lasers.
… at $\sim$707 nm is observed at 77 Kelvin with a threshold current of 175 milliamperes for a 60-$\mu$m by 400-$\mu$m broad area laser. A measured external quantum efficiency of $\sim$8.5% at low temperature with a peak power greater than 200 milliwatts demonstrate good size distribution and high …
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LOW-TEMPERATURE CHARACTERIZATION OF A 1.55-μm MULTIPLE-QUANTUM-WELL LASER DOWN TO 10 K
… of important laser parameters, such as threshold current, differential efficiency, emission wavelength, and series resistance, extracted from conventional L-I/I-V and spectral measurements, is presented and analyzed. The results indicate that a diode laser designed for room-temperature …
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Tolimosios infraraudonosios srities optoelektronikos įtaisų žemo dažnio triukšmo charakteristikos /
… 1/𝑓 noise, and 1/𝑓𝛾 noise. Initially peak at low currents (~0,003 mA), then decreasing with higher currents. When measuring at lower temperatures the rise from 77 K to 293 K shifted noise from 1/𝑓 and 1/𝑓𝛾 to a Lorentzian spectrum, indicating active recombination centers. The measurements of …
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Numerical Simulation and Experimental Investigation of Quantum Dash Lasers at Elevated Temperatures: Design and Operation of Monolithic InAs/InP Quantum Dash Ridge Laser Diodes Operating in the C-Band
… of their performance to temperature, and lower threshold current densities. Dashes additionally offer higher peak gain and broader gain bandwidths, but show higher phase noise than dots. We develop a quantum dash laser model in a commercial laser simulation package, Crosslight PICS3D, that …
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Dielectric micro-cavity surface-emitting lasers
… wave, electrical injection at room temperature. Threshold currents from devices with different diameters were collected for further study. The working devices generally had threshold currents around hundreds of µA, while their metal-cavity counterparts had previously-reported threshold currents …
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Design and Characterization of Quantum-Cascade Lasers
… with the lasing wavelength of 104 mum. The light-current-voltage characteristics as well as the lasing spectrum are measured at different temperature. The characteristic temperature is extracted to be 144 K, while the quantum efficiency is found to be around 8-13% with the tunability of 2 nm/K. …
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Design and fabrication of quantum-dot lasers
… and quantum-well counterparts namely: low threshold current, high differential gain and highly temperature stable light-current characteristics. This thesis investigates the lasing characteristics of a ridge-waveguide laser containing seven layers of quantum dots as the active region. A …
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Vertical cavity surface emitting lasers.
… wave dielectric reflector stacks through which current is injected. The reflection spectra of these stacks is studied in detail; the effects on the laser threshold gain of absorption due to impurities and of errors in growth are investigated. Methods of disruption of the AlAs / GaAs …
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MOVPE metamorphic lasers and nanostructures engineering at telecom wavelengths
… and 2.5 µm wide stripe waveguide exhibited a threshold current (Ith) of ∼ 152 mA, corresponding to a density threshold current (Jth) of ∼ 127 mA/cm2 per QWs , operating at room temperature in pulse mode. The turning voltage was ∼ 0.8 V and the resistance series was 4.5 Ω. The emission …
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RF wave observations in beam-plasma discharge
… A V^-3/2). A more complete expression of the threshold current IC taking into account the pitch angle injection dependence is given. Ambient plasma density inferred from wave measurements under various beam conditions are reported. It is observed that the maximum frequency of the excited RF …
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THE STUDY OF PERPENDICULARLY MAGNETIZED COFE/PD MULTILAYERS FOR DOMAIN WALL MOTION
… width and high spin polarization can induce low threshold current density for DW motion in CoFe/Pd superlattice-like multilayer films. Next, we show that DW motion can be driven by a low Jth with small bias field in the CoFe/Pd multilayers-based nanowires. The combination of non-adiabatic …
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Circuit-Level Modeling and Simulation of Semiconductor Lasers
… incorporates a temperature-dependent offset current into the standard laser rate equations in order to describe thermally dependent threshold current and output-power rollover in the LI characteristics. The second model is a comprehensive circuit level model in SABER which uses analytical …
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Fabrication and characterization of compound semiconductor nanostructures
… quantum structures is predicted to improve the threshold current, increase the modulation bandwidth, yield narrower spectral linewidths, and reduce temperature sensitivity in semiconductor lasers. This thesis reports the development and characterization of several fabrication techniques of …
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Characterization of optically pumped interband cascade lasers.
… wavelengths ranging from 1800 to 1940 nm. The threshold pump intensity and slope efficiency were also determined from the light-light curves. Additionally, samples with a graphene contact layer were optically pumped and also evidenced lasing characteristics. This demonstrates the feasibility of …
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Materials science and design for germanium monolithic light source on silicon
… focuses on: (1) physical understandings of the threshold behavior of Ge-on-Si bulk laser and the temperature dependent performance; (2) process developments to grow and planarize the epitaxial Ge on Si in oxide trenches and corners; (3) introduction of n-type dopant into Ge-on-Si thin films …
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