The Experts below are selected from a list of 129606 Experts worldwide ranked by ideXlab platform
Mario J Paniccia - One of the best experts on this subject based on the ideXlab platform.
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a Continuous Wave raman silicon laser
Nature, 2005Co-Authors: Haisheng Rong, Dani Hak, Ansheng Liu, Alexander W Fang, Richard Jones, Oded Cohen, Mario J PanicciaAbstract:Last month, Intel researchers reported a notable advance in optoelectronics (Nature 433, 292–294; 2005). They had produced an all-silicon laser on a single chip, making silicon, the foundation of modern microelectronics, a real prospect for optical applications. Now Intel's labs report the first experimental demonstration of a Continuous Wave laser in a silicon Waveguide cavity on a single chip. This is another step towards silicon-based optoelectronic circuits for applications in communications and computing. Achieving optical gain and/or lasing in silicon has been one of the most challenging goals in silicon-based photonics1,2,3 because bulk silicon is an indirect bandgap semiconductor and therefore has a very low light emission efficiency. Recently, stimulated Raman scattering has been used to demonstrate light amplification and lasing in silicon4,5,6,7,8,9. However, because of the nonlinear optical loss associated with two-photon absorption (TPA)-induced free carrier absorption (FCA)10,11,12, until now lasing has been limited to pulsed operation8,9. Here we demonstrate a Continuous-Wave silicon Raman laser. Specifically, we show that TPA-induced FCA in silicon can be significantly reduced by introducing a reverse-biased p-i-n diode embedded in a silicon Waveguide. The laser cavity is formed by coating the facets of the silicon Waveguide with multilayer dielectric films. We have demonstrated stable single mode laser output with side-mode suppression of over 55 dB and linewidth of less than 80 MHz. The lasing threshold depends on the p-i-n reverse bias voltage and the laser Wavelength can be tuned by adjusting the Wavelength of the pump laser. The demonstration of a Continuous-Wave silicon laser represents a significant milestone for silicon-based optoelectronic devices.
J L Carlsten - One of the best experts on this subject based on the ideXlab platform.
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Continuous Wave raman laser in h 2
Optics Letters, 1998Co-Authors: J K Brasseur, Kevin S Repasky, J L CarlstenAbstract:Recent developments in high-finesse cavities now make broadly tunable, Continuous-Wave Raman lasers possible. The design and preliminary characterization of what is to the authors' knowledge the first Continuous-Wave Raman laser in H(2) are presented. The threshold is currently at 2 mW of pump, making diode laser pumping possible. The maximum photon conversion efficiency observed was 35% at 7.6 mW of pump power.
Stephanie Czasch - One of the best experts on this subject based on the ideXlab platform.
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Continuous Wave all optoelectronic terahertz imaging
Applied Physics Letters, 2002Co-Authors: Karsten Siebert, Holger Quast, R Leonhardt, Torsten Loffler, Mark D Thomson, T Bauer, Hartmut G Roskos, Stephanie CzaschAbstract:We present an all-optoelectronic THz imaging system based on photomixing of two Continuous-Wave laser beams using photoconductive antennas. For a specific biological sample, we compare Continuous-Wave THz imaging and pulsed THz imaging at 1 THz with respect to data-acquisition time and signal-to-noise ratio, and discuss image formation from both amplitude and phase data. In addition, we introduce the application of hyperboloidal lenses which allow tighter focusing and a corresponding improvement in spatial resolution compared to off-axis paraboloidal mirrors.
Stéphane Coen - One of the best experts on this subject based on the ideXlab platform.
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The role of pump incoherence in Continuous-Wave supercontinuum generation
Optics express, 2005Co-Authors: Frédérique Vanholsbeeck, Sonia Martin-lopez, Miguel Gonzalez-herraez, Stéphane CoenAbstract:Supercontinuum generation can be achieved in the Continuous-Wave regime with a few watts of pump power launched into kilometer-long fibers. High power spectral density broadband light sources can be obtained in this way. Using a generalized nonlinear Schrodinger equation model and an ensemble averaging procedure that takes into account the partially-coherent nature of the pump laser, we fully explain for the first time the spectral broadening mechanisms underlying this process. Our simulations and experiments confirm that Continuous-Wave supercontinuum generation involve Raman soliton dynamics and dispersive Waves in a way akin to pulsed supercontinua. The Raman solitons are however generated with a wide distribution of parameters because they originate from the random phase and intensity fluctuations associated with the pump incoherence. This soliton distribution is averaged out by experimental measurements, which explains the remarkable smoothness of experimental Continuous-Wave supercontinuum spectra.
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Numerical Modeling of Continuous-Wave Supercontinuum Generation
Nonlinear Guided Waves and Their Applications, 2005Co-Authors: Frédérique Vanholsbeeck, Stéphane Coen, Sonia Martin-lopez, Miguel Gonzalez-herraezAbstract:Continuous-Wave supercontinuum generation is studied numerically. We show that the random fluctuations of the partially coherent pump beam play a dominant role in the spectral broadening process and explain the smoothness of experimental spectra.
Martin Koch - One of the best experts on this subject based on the ideXlab platform.
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Hybrid Continuous Wave terahertz spectroscopy.
Optics express, 2010Co-Authors: Maik Scheller, Matthias Stecher, Marina Gerhard, Martin KochAbstract:We propose a hybrid architecture for Continuous Wave terahertz spectroscopy employing a conventional two color photomixing system combined with a quasi time domain spectrometer, driven by a multimode laser diode. This approach fuses high spectral intensity with broadband frequency information and overcomes the ambiguity of standard Continuous Wave thickness measurements.
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Hybrid Continuous Wave terahertz system
35th International Conference on Infrared Millimeter and Terahertz Waves, 2010Co-Authors: Matthias Stecher, Maik Scheller, Martin KochAbstract:We present a hybrid Continuous Wave terahertz system, combining a two color photomixing system with a quasi time domain spectrometer, driven by a multimode laser diode. Overcoming the ambiguity of standard Continuous Wave thickness measurements is shown on different samples.
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Continuous-Wave THz imaging
Electronics Letters, 2001Co-Authors: Thomas Kleine-ostmann, Martin Koch, P. Knobloch, S. Hoffmann, Martin Breede, Martin R. Hofmann, G. Hein, Klaus Pierz, M. Sperling, K. DonhuijsenAbstract:The first THz imaging spectrometer based on Continuous-Wave THz radiation is presented. The new setup is less expensive than conventional time-domain imaging systems that comprise femtosecond lasers. The system uses a two-colour external-cavity laser diode. Hence it is much more compact as compared to systems based on optically pumped solid-state lasers. As an example we investigate a human liver with metastasis.
