The Experts below are selected from a list of 3624 Experts worldwide ranked by ideXlab platform
Nathalie Picqué - One of the best experts on this subject based on the ideXlab platform.
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dual comb coherent raman spectroscopy with lasers of 1 ghz pulse repetition frequency
Optics Letters, 2017Co-Authors: Kathrin J. Mohler, Bernhard J. Bohn, Ming Yan, Theodor W. Hänsch, Gwenaelle Melen, Nathalie PicquéAbstract:We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstRate a spectra of liquids, which span 1100 cm−1 of Raman shifts. At a resolution of 6 cm−1, their measurement time may be as short as 5 μs for a Refresh Rate of 2 kHz. The waiting period between acquisitions is improved 10-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies.
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Dual-Comb Coherent Raman Spectroscopy with Lasers of 1-GHz Pulse Repetition Frequency
Optics letters, 2017Co-Authors: Kathrin J. Mohler, Bernhard J. Bohn, Ming Yan, Theodor W. Hänsch, Nathalie PicquéAbstract:We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstRate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts. At a resolution of 6 cm$^{-1}$, their measurement time may be as short as 5 microseconds for a Refresh Rate of 2 kHz. The waiting period between acquisitions is improved ten-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies.
Shuai Wang - One of the best experts on this subject based on the ideXlab platform.
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broadband and high resolution electro optic dual comb interferometer with frequency agility
Optics Express, 2019Co-Authors: Xinyu Fan, Shuai WangAbstract:We propose a broadband and high-resolution dual-comb interferometer (DCI) realized with dense electro-optic frequency combs (EOFCs), which are geneRated with two-stage electro-optic modulation and nonlinear fiber spectral broadening. The broadband coarse comb is geneRated in the first-stage modulation and the space between neighboring combs is filled with a dense electrical comb in the second-stage modulation. The spectral resolution of the DCI can be flexibly changed from 10 MHz to 1 GHz easily as required, and electro-optic DCIs with 10-MHz, 100-MHz, and 1-GHz frequency resolutions are experimentally realized. Meanwhile, DCI working in the quasi-integer-ratio mode is easily implemented in this system for the increased Refresh Rate and improved figure of merit especially for high resolution. As a demonstration, 150000 comb lines with 10 MHz frequency interval are resolved in the experiment.
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hybrid dual comb interferometer with easily established mutual coherence and a very high Refresh Rate
Optics Letters, 2018Co-Authors: Shuai Wang, Bingxin Xu, Jiangbing Du, Bin Wang, Zuyuan HeAbstract:In this Letter, we propose a hybrid dual-comb interferometer (DCI) with a free-running mode-locked laser and an electro-optic frequency comb. The mutual coherence of this DCI is achieved by using an injection locking technique without any complicated phase-locking loops or post data processing algorithms. The proposed architecture is validated by resolving more than 10,000 comb lines of 250 MHz spacing with a Refresh Rate of 500 kHz. This combination of two kinds of optical frequency comb sources is suitable for wideband spectroscopic applications, where modeRate spectral resolutions as well as high Refresh Rates are necessary.
Thierry Debuisschert - One of the best experts on this subject based on the ideXlab platform.
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wide bandwidth instantaneous radio frequency spectrum analyzer based on nitrogen vacancy centers in diamond
Applied Physics Letters, 2015Co-Authors: Mayeul Chipaux, Loic Toraille, C Larat, Loic Morvan, Sebastien Pezzagna, J Meijer, Thierry DebuisschertAbstract:We propose an original analog method to perform instantaneous and quantitative spectral analysis of microwave signals. An ensemble of nitrogen-vacancy (NV) centers held in a diamond plate is pumped by a 532 nm laser. Its photoluminescence is imaged through an optical microscope and monitored by a digital camera. An incoming microwave signal is converted into a microwave field in the area of the NV centers by a loop shaped antenna. The resonances induced by the magnetic component of that field are detected through a decrease of the NV centers photoluminescence. A magnetic field gradient induces a Zeeman shift of the resonances and transforms the frequency information into spatial information, which allows for the simultaneous analysis of the microwave signal in the entire frequency bandwidth of the device. The time dependent spectral analysis of an amplitude modulated microwave signal is demonstRated over a bandwidth of 600 MHz, associated to a frequency resolution of 7 MHz , and a Refresh Rate of 4 ms. Wi...
Kathrin J. Mohler - One of the best experts on this subject based on the ideXlab platform.
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dual comb coherent raman spectroscopy with lasers of 1 ghz pulse repetition frequency
Optics Letters, 2017Co-Authors: Kathrin J. Mohler, Bernhard J. Bohn, Ming Yan, Theodor W. Hänsch, Gwenaelle Melen, Nathalie PicquéAbstract:We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstRate a spectra of liquids, which span 1100 cm−1 of Raman shifts. At a resolution of 6 cm−1, their measurement time may be as short as 5 μs for a Refresh Rate of 2 kHz. The waiting period between acquisitions is improved 10-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies.
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Dual-Comb Coherent Raman Spectroscopy with Lasers of 1-GHz Pulse Repetition Frequency
Optics letters, 2017Co-Authors: Kathrin J. Mohler, Bernhard J. Bohn, Ming Yan, Theodor W. Hänsch, Nathalie PicquéAbstract:We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstRate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts. At a resolution of 6 cm$^{-1}$, their measurement time may be as short as 5 microseconds for a Refresh Rate of 2 kHz. The waiting period between acquisitions is improved ten-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies.
Yungchang Chen - One of the best experts on this subject based on the ideXlab platform.
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adaptive error resilience transcoding using prioritized intra Refresh for video multicast over wireless networks
Signal Processing-image Communication, 2007Co-Authors: Chihming Chen, Yungchang ChenAbstract:In this paper, we propose a two-pass error-resilience transcoding scheme based on adaptive intra-Refresh for inserting error-resilience features to a compressed video at the intermediate transcoder of a three-tier streaming system. The proposed transcoder adaptively adjusts the intra-Refresh Rate according to the video content and the channel's packet-loss Rate to protect the most important macroblocks against packet loss. In this work, we consider the problem of multicast of video to multiple clients having dispaRate channel-loss profiles. We propose a MINMAX loss Rate estimation scheme to determine a single intra-Refresh Rate for all the clients in a multicast group. For the scenario that a quality variation constraint is imposed on the users, we also propose a grouping method to partition a multicast group of heterogeneous users into a minimal number of subgroups to minimize the channel bandwidth consumption while meeting the quality variation constraint. Experimental results show that the proposed method can effectively mitigate the error propagation due to packet loss as well as achieve fairness among clients in a multicast.
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error resilience transcoding using prioritized intra Refresh for video multicast over wireless networks
International Conference on Multimedia and Expo, 2005Co-Authors: Chihming Chen, Yungchang ChenAbstract:In this paper, we propose a two-pass intra-Refresh transcoding scheme for inserting error-resilience features to a compressed video at the media gateway of a three-tier streaming system. The proposed transcoder can adaptively vary the intra-Refresh Rate according to the video content and the channel's packet-loss Rate to protect the most important macroblocks (MBs) against packet loss. In this work, we consider the problem of multicast of video to multiple clients having dispaRate channel loss profiles. We propose a minmax loss-Rate estimation scheme to select a single intra-Refresh Rate for all the clients. Experimental results show that the proposed method can effectively mitigate the error propagation due to packet loss, and its fairness for multicast
