Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
A new self-mixing interferometry quadrature demodulation method based on a lock-in amplifier technique is proposed. Sinusoidal phase modulation of the beam is obtained by an electro-optic modulator (EOM) in the external cavity. Then the real phase of the external target can be calculated by lock-in amplifier analysis method. In this paper, the validity of the proposed method is confirmed by theoretical analysis and means of simulated signals, and then it is demonstrated by several experimental measurements for target harmonic and arbitrary motion. The results show that the proposed method can get a high-precision measurement, even using a diffusive target.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/AO.58.006098 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Highly accurate adjustment and stabilization of a fiber interferometer for displacement measurements.
Rev Sci Instrum
September 2025
Institut für Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany.
An interferometer used for displacement measurement is typically adjusted to the center or another appropriate point of the interferometer fringe as a working point to yield maximum detection sensitivity and linearity. The interferometer is prone to varying misalignment in the course of measurements, most noticeable due to thermal drift affecting the interferometer dimensions. We introduce an automatic correction mechanism based on a proportional/integral (PI) control loop to remove any error in the alignment of the fiber interferometer, specifically long-term drift.
View Article and Find Full Text PDFIs postoperative cognitive dysfunction a disease of microglial inflammatory memory? A state-transition model from metabolic stress to epigenetic lock-in.
Front Mol Neurosci
August 2025
Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China.
Postoperative cognitive dysfunction (POCD) remains a significant challenge in perioperative medicine, especially among older adults. Despite its prevalence, existing models centered on transient neuroinflammation fail to explain why cognitive deficits often persist long after systemic immune responses resolve. This review proposes a new framework: POCD is driven not by ongoing inflammation, but by a stable shift in microglial identity.
View Article and Find Full Text PDFLaser-induced fluorescence has been a staple technique for in-situ probing of radicals and atomic species for decades. The multi-photon equivalent is prevalent in a large variety of applications, where such excitation schemes enable the study of otherwise elusive species and systems. However, these variants inherently suffer from low signal intensities, impeding the broader use of multi-photon imaging.
View Article and Find Full Text PDFWe demonstrate a terahertz asynchronous optical sampling (THz-ASOPS) spectrometer incorporating a lock-in amplifier. The experimental setup employs a high-voltage pulse generator to drive a photoconductive antenna emitter, generating precisely modulated terahertz pulses that are subsequently detected by a photoconductive antenna detector. The detection system features a two-stage amplification process: initial signal amplification through a low-noise current preamplifier, followed by processing with a digital lock-in amplifier.
View Article and Find Full Text PDFCharacterizing nanoscale spatiotemporal defects of multi-layered MoSe in hyper-temporal transient nanoscopy.
Nanophotonics
August 2025
Material Property Metrology Group, Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea.
We directly characterize nanoscale spatiotemporal inhomogeneities of multi-layered molybdenum diselenide (MoSe) in real space and time - the nanometre-femtosecond scale, attributing to local mechanical structures such as strain and surface/subsurface defects, which are critical in semiconductor and optoelectronic applications. This remarkable precision is achieved through the development of a hyper-temporal transient nanoscopy incorporating a sideband-coupled generalized lock-in amplification technique, allowing for characterization of local spatiotemporal defects at each pixel within a subwavelength mapping region. By utilizing this technique, we characterize the nanoscale strain-induced spatiotemporal defects of multi-layered MoSe, including nano-bubbles that exhibit a noticeable reduction in exciton-exciton annihilation rates, which may attribute to the suppressed probability of bimolecular interaction of excitons due to the strain-induced band distortion.
View Article and Find Full Text PDF