Analysis of distributed temperature sensing based on Raman scattering using OTDR coding and discrete Raman amplification
Graph Chatbot
Chat with Graph Search
Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
Infrared spectroscopy using semiconductor lasers is a promising technique for trace gas detection. It allows a continuous and real time monitoring of several species, with a high sensitivity and a good selectivity. Among all the possible methods two are pa ...
An experimental method is presented for characterization of the combined intensity and frequency modulation produced when the injection current of a laser diode is modulated. The reported technique is based on the analysis of the harmonic signals produced ...
Self-assembled quantum-dots (QDs) represent a distributed ensemble of zero dimensional structures with a near-singular density of states. Implemented as the active medium in a diode laser their unique properties lead to improved and often novel characteris ...
A heterodyne laser Doppler interferometer operating up to 100 MHz with an optical vibration excitation function was implemented to enable frequency detection of nanocantilevers. By using the stimulant of a network analyzer to sweep the modulation frequency ...
In 2-color optical Kerr effect measurements of water, addnl. signals can occur in the pulse overlap region if the energy difference between pump and probe pulses approaches the Raman resonance of the OH-stretch vibration. These features can be understood b ...
We show that stimulated polariton scattering in a semiconductor microcavity is observable over a wide range of laser pump angles. The ratio of idler to signal beams is found to vary strongly with angle, consistent with the expected variation of the photon ...
We have investigated the thermal stability of GaN using Raman scattering. Noninvasive optical monitoring of structural damage to GaN by high-temperature anneals in nitrogen ambient has been demonstrated. Characteristic features in the Raman spectrum identi ...
Raman scattering turns out to be very detrimental for long-range Brillouin time-domain analysis. The conditions under which this problem occurs are studied, as well as possible strategies to avoid it. ...
The dependence of stimulated polariton-polariton scattering in InGaAs/GaAs/AlGaAs microcavities on pump power, angle, and energy is investigated. We show that contrary to much previous belief there is no "magic angle" for stimulated scattering under contin ...
A theoretical model of wavelength modulation spectroscopy that uses a laser diode on a Lorentzian absorption line is presented. This theory describes the general case of a current-modulated semiconductor laser for which a combined intensity and frequency m ...