The Experts below are selected from a list of 62658 Experts worldwide ranked by ideXlab platform
Christian Pedersen - One of the best experts on this subject based on the ideXlab platform.
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all Semiconductor Laser doppler anemometer at 1 55 microm
Optics Express, 2008Co-Authors: Rene Skov Hansen, Christian PedersenAbstract:We report to our best knowledge the first all Semiconductor Laser Doppler Anemometer (LIDAR) for wind speed determination. We will present the design and first experimental results on a focusing coherent cw Laser Doppler anemometer for measuring atmospheric wind velocities in the 10 meters to 300 meters distance range. Especially, we will demonstrate that both the output power as well as the demanding coherence properties required from the Laser source can be accomplished by an all Semiconductor Laser. Preliminary tests at a distance of 40 meters indicate a typical signal to noise ratio of 9 dB. This result is obtained at a clear day with an up-date rate of 12 Hz.
Rene Skov Hansen - One of the best experts on this subject based on the ideXlab platform.
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all Semiconductor Laser doppler anemometer at 1 55 microm
Optics Express, 2008Co-Authors: Rene Skov Hansen, Christian PedersenAbstract:We report to our best knowledge the first all Semiconductor Laser Doppler Anemometer (LIDAR) for wind speed determination. We will present the design and first experimental results on a focusing coherent cw Laser Doppler anemometer for measuring atmospheric wind velocities in the 10 meters to 300 meters distance range. Especially, we will demonstrate that both the output power as well as the demanding coherence properties required from the Laser source can be accomplished by an all Semiconductor Laser. Preliminary tests at a distance of 40 meters indicate a typical signal to noise ratio of 9 dB. This result is obtained at a clear day with an up-date rate of 12 Hz.
U Keller - One of the best experts on this subject based on the ideXlab platform.
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passively mode locked diode pumped surface emitting Semiconductor Laser
IEEE Photonics Technology Letters, 2000Co-Authors: Sjoerd Hoogland, A C Tropper, S Dhanjal, J S Roberts, R Haring, Rudiger Paschotta, F Moriergenoud, U KellerAbstract:A surface-emitting Semiconductor Laser has been passively mode locked in an external cavity incorporating a Semiconductor saturable absorber mirror. The gain medium consists of a stack of 12 InGaAs-GaAs strained quantum wells, grown above a Bragg mirror structure, and pumped optically by a high-brightness diode Laser. The mode-locked Laser emits pulses of 22-ps full-width at half maximum duration at 1030 nm, with a repetition rate variable around 4.4 GHz.
A Y Cho - One of the best experts on this subject based on the ideXlab platform.
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ultra broadband Semiconductor Laser
Nature, 2002Co-Authors: Claire F. Gmachl, Deborah L. Sivco, Federico Capasso, R Colombelli, A Y ChoAbstract:The fundamental mechanism behind Laser action leads in general only to narrowband, single-wavelength emission. Several approaches for achieving spectrally broadband Laser action have been put forward, such as enhancing the optical feedback in the wings of the gain spectrum, multi-peaked gain spectra, and the most favoured technique at present, ultrashort pulse excitation. Each of these approaches has drawbacks, such as a complex external Laser cavity configuration, a non-flat optical gain envelope function, or an inability to operate in continuous mode, respectively. Here we present a monolithic, mid-infrared 'supercontinuum' Semiconductor Laser that has none of these drawbacks. We adopt a quantum cascade configuration, where a number of dissimilar intersubband optical transitions are made to cooperate in order to provide broadband optical gain from 5 to 8 microm wavelength. Laser action with a Fabry-Perot spectrum covering all wavelengths from 6 to 8 microm simultaneously is demonstrated with this approach. Lasers that emit light over such an extremely wide wavelength range are of interest for applications as varied as terabit optical data communications or ultra-precision metrology and spectroscopy.
Rajeev J Ram - One of the best experts on this subject based on the ideXlab platform.
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comprehensive heat exchange model for a Semiconductor Laser diode
IEEE Photonics Technology Letters, 2003Co-Authors: Kevin P Pipe, Rajeev J RamAbstract:By measuring the total energy flow from an optical device, we can develop new design strategies for thermal stabilization. Here we present a comprehensive model for heat exchange between a Semiconductor Laser diode and its environment that includes the mechanisms of conduction, convection, and radiation. We perform quantitative measurements of these processes for several devices, deriving parameters such as a Laser's heat transfer coefficient, and then demonstrate the feasibility of thermal probing for the nondestructive wafer-scale characterization of optical devices.
