The Experts below are selected from a list of 73104 Experts worldwide ranked by ideXlab platform
Thierry Bosch - One of the best experts on this subject based on the ideXlab platform.
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toward an estimation of the optical Feedback Factor c on the fly for displacement sensing
Sensors, 2021Co-Authors: Olivier D Bernal, Usman Zabit, Francis Jayat, Thierry BoschAbstract:In this paper, a method based on the inherent event-based sampling capability of laser optical Feedback interferometry (OFI) is proposed to assess the optical Feedback Factor C when the laser operates in the moderate and strong Feedback regimes. Most of the phase unwrapping open-loop OFI algorithms rely on the estimation of C to retrieve the displacement with nanometric precision. Here, the proposed method operates in open-loop configuration and relies only on OFI’s fringe detection, thereby improving its robustness and ease of use. The proposed method is able to estimate C with a precision of <5%. The obtained performances are compared to three different approaches previously published and the impacts of phase noise and sampling frequency are reported. We also show that this method can assess C on the fly even when C is varying due to speckle. To the best of the authors’ knowledge, these are the first reported results of time-varying C estimation. In addition, through C estimation over time, it could pave the way not only to higher performance phase unwrapping algorithms but also to a better control of the optical Feedback level via the use of an adaptive lens and thus to better displacement retrieval performances.
Thierry M Bosch - One of the best experts on this subject based on the ideXlab platform.
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optical Feedback self mixing interferometry with a large Feedback Factor c behavior studies
IEEE Journal of Quantum Electronics, 2009Co-Authors: Joe F Chicharo, Thierry M BoschAbstract:This paper studies the behavior of optical Feedback self-mixing interferometric (OFSMI) systems, where the semiconductor lasers operate at a single mode (perturbed external cavity mode) with a large optical Feedback Factor C. Based on analysis of the spectral linewidth associated with all the possible lasing modes at different C values, a set of mode jumping rules are proposed following the minimum linewidth mode competition principle proposed in . According to the rules, the C Factor can be classified into different regions, on which an OFSMI system will exhibit distinct phenomena. In particular, for the same amount of displacement associated with the external cavity, the fringe number reduction on the OFSMI signal should be observed when C increases from one region to the next. An experimental setup with a laser diode HL7851G was implemented and employed to verify the proposed rules. The behavior of the OFSMI predicted by the paper has been confirmed by the experiments with C value up to 8.0.
Olivier D Bernal - One of the best experts on this subject based on the ideXlab platform.
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toward an estimation of the optical Feedback Factor c on the fly for displacement sensing
Sensors, 2021Co-Authors: Olivier D Bernal, Usman Zabit, Francis Jayat, Thierry BoschAbstract:In this paper, a method based on the inherent event-based sampling capability of laser optical Feedback interferometry (OFI) is proposed to assess the optical Feedback Factor C when the laser operates in the moderate and strong Feedback regimes. Most of the phase unwrapping open-loop OFI algorithms rely on the estimation of C to retrieve the displacement with nanometric precision. Here, the proposed method operates in open-loop configuration and relies only on OFI’s fringe detection, thereby improving its robustness and ease of use. The proposed method is able to estimate C with a precision of <5%. The obtained performances are compared to three different approaches previously published and the impacts of phase noise and sampling frequency are reported. We also show that this method can assess C on the fly even when C is varying due to speckle. To the best of the authors’ knowledge, these are the first reported results of time-varying C estimation. In addition, through C estimation over time, it could pave the way not only to higher performance phase unwrapping algorithms but also to a better control of the optical Feedback level via the use of an adaptive lens and thus to better displacement retrieval performances.
O Kwonhyok - One of the best experts on this subject based on the ideXlab platform.
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effect of linewidth enhancement Factor on fringe in a self mixing signal and improved estimation of Feedback Factor in laser diode
IEEE Access, 2019Co-Authors: O KwonhyokAbstract:The optical output power of a laser diode is modulated by the self-mixing effect when the optical beam is back-reflected or back-scattered into the laser cavity by a target. The optical Feedback Factor C is the most important one that defines the feature of the self-mixing signals (SMSs). And the estimation of C is indispensable for the displacement reconstruction by the phase unwrapping method because it is impossible to reconstruct the displacement with sub-wavelength resolution, provided the exact value of C is unknown. Unfortunately, C is subject to constant change during the measurement and, what is worse; its estimation is usually very time-consuming. This paper studies the feature of a high and low fringe of SMSs in moderate and strong Feedback regime and the effect of the Feedback Factor and the linewidth enhancement Factor on the fringes and presents a simple approach to the estimation of C when C > 1.5 based on the behavioral model proposed by Plantier et al. In particular, the novel approach enables fast direct estimation of C because it is based on analytic relations between C and the amplitudes of the high and low peak in SMSs.
Joe F Chicharo - One of the best experts on this subject based on the ideXlab platform.
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optical Feedback self mixing interferometry with a large Feedback Factor c behavior studies
IEEE Journal of Quantum Electronics, 2009Co-Authors: Joe F Chicharo, Thierry M BoschAbstract:This paper studies the behavior of optical Feedback self-mixing interferometric (OFSMI) systems, where the semiconductor lasers operate at a single mode (perturbed external cavity mode) with a large optical Feedback Factor C. Based on analysis of the spectral linewidth associated with all the possible lasing modes at different C values, a set of mode jumping rules are proposed following the minimum linewidth mode competition principle proposed in . According to the rules, the C Factor can be classified into different regions, on which an OFSMI system will exhibit distinct phenomena. In particular, for the same amount of displacement associated with the external cavity, the fringe number reduction on the OFSMI signal should be observed when C increases from one region to the next. An experimental setup with a laser diode HL7851G was implemented and employed to verify the proposed rules. The behavior of the OFSMI predicted by the paper has been confirmed by the experiments with C value up to 8.0.
