Dissertation/Thesis
Advanced laser diagnostics using dual-comb spectroscopy
| Τίτλος: | Advanced laser diagnostics using dual-comb spectroscopy |
|---|---|
| Συνεισφορές: | Xu, Ke (author.), Ren, Wei (thesis advisor.), Chinese University of Hong Kong Graduate School. Division of Mechanical and Automation Engineering. (degree granting institution.) |
| Έτος έκδοσης: | 2020 |
| Συλλογή: | The Chinese University of Hong Kong: CUHK Digital Repository / 香港中文大學數碼典藏 |
| Θεματικοί όροι: | Diagnostic imaging, Spectrum analysis--Diagnostic use, Molecular spectroscopy, Optical Imaging--methods, Spectrum Analysis--methods, Molecular Imaging--methods, Optics and Photonics, Lasers, Semiconductor |
| Περιγραφή: | Ph.D. ; Real-time and high-resolution spectroscopic techniques play very important roles in many applications such as atmospheric monitoring, combustion diagnostics, and human breath analysis. In laser diagnostics, a broad spectral bandwidth is preferred to cover more spectral features of various gas molecules; a high spectral resolution is needed for the identification and quantitative analysis of the individual spectral signatures; and a high sensitivity is required for the quantitative determination of trace gases with a weak absorption. Additionally, the sensing system should be simple and portable enough to be suitable for field applications. ; Optical frequency comb (OFC) spectroscopy has recently emerged as a novel optical diagnostic method with the advantages of large bandwidth, high resolution, and fast time-response. In the time domain, it is represented by a train of ultrashort pulses, and in the frequency domain, the spectrum of the output comb is composed of a series of discrete narrow lines evenly spaced by the repetition frequency. Based on these special optical features, the OFC-based Fourier transform spectroscopy takes advantage of high resolution with a single photodetector. However, the resolution is limited by the excursion of the moving parts and the sampling time of the Fourier transform system. ; Dual-comb spectroscopy (DCS) is recently developed as an all-static Fourier transform interferometry using two coherent OFCs without any moving parts. In DCS, a pair of frequency combs are normally generated from two ultrafast mode-locked lasers phase-locked with a slight difference in their repetition frequencies. These two optical combs beat on a photodiode and generate a radio frequency (RF) comb between the pairs of comb teeth. However, the sophisticated and expensive phase-locking systems are required to ensure the mutual coherence between these two mode-locked laser sources. Additionally, precise electronic feedbacks and stable environments are commonly needed, thus making it hard for field ... |
| Τύπος εγγράφου: | Thesis |
| Περιγραφή αρχείου: | electronic resource; remote; 1 online resource (ii, ii, xx, 80 leaves) : illustrations (some color); computer; online resource |
| Γλώσσα: | English Chinese |
| Relation: | cuhk:2627832; local: ETD920210229; local: AAI28506450; local: 991040013773103407 |
| Διαθεσιμότητα: | https://julac.hosted.exlibrisgroup.com/primo-explore/search?query=addsrcrid,exact,991040013773103407,AND&tab=default_tab&search_scope=All&vid=CUHK&mode=advanced&lang=en_US https://repository.lib.cuhk.edu.hk/en/item/cuhk-2627832 |
| Rights: | Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-NoDerivatives 4.0 International" License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
| Αριθμός Καταχώρησης: | edsbas.2586BCC6 |
| Βάση Δεδομένων: | BASE |
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