- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Optical Interferometry || Applications of Fiber-Optic Interferometry Technology in Sensor Fields
摘要： Optical interferometry as a precision metrology has been widely employed in many aspects for accurate measurements of various physical quantities. As an important branch of measurement technology, now the fiber-optic interferometry technology, based on fiber-optic and laser technologies, has been developed and widely applied in sensor fields for detections of various unknown or uncontrolled physical parameters. In this chapter, basic concepts of fiber-optic interferometry are presented and clarified. Also, three novel fiber-optic sensors, based on the optical interferometry technology and mainly used in the power industry for equipment failure monitoring, are demonstrated.
关键词： optical interferometry,fiber-optic sensor,fiber Bragg grating-based interferometer,interference fringe,laser
更新于2025-09-23 15:21:21
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Optical Fiber Applications || Optical Fibers Profiling Using Interferometric and Digital Holographic Methods
摘要： Optical fibers are extensively used in modern technology such as sensing, short-distance and long-distance telecommunications. This motivated many researchers to present different methods in order to characterize optical fibers and determine their refractive index profiles. In addition, variation of refractive index profiles of optical fibers suffering mechanical stresses or other external effects reflects good information about the internal structure of these fibers and how they are responding to these external effects. Optical interferometry and digital holography methods are accurate and effective tools used to achieve this task. In this chapter, we illustrate the application of different types of optical interference on conventional, polarizing maintaining and thick optical fibers. Also, we illustrate some mathematical interpretations (and recently automatic analyzing of interference patterns) that have been used to reconstruct the accurate refractive index profiles of optical fibers. Some experimental interferograms and refractive index profiles are demonstrated as well.
关键词： optical interferometry,refractive index profile,digital holography,optical fiber,interferogram analyses
更新于2025-09-23 15:19:57
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The implementation and data analysis of an interferometer for intense short pulse laser experiments
摘要： We present an interferometry setup and the detailed fringe analysis method for intense short pulse (SP) laser experiments. The interferometry scheme was re?ned through multiple campaigns to investigate the effects of pre-plasmas on energetic electrons at the Jupiter Laser Facility at Lawrence Livermore National Laboratory. The interferometer used a frequency doubled (λ = 0.527 μm) 0.5 ps long optical probe beam to measure the pre-plasma density, an invaluable parameter to better understand how varying pre-plasma conditions affect the characteristics of the energetic electrons. The hardware of the diagnostic, data analysis and example data are presented. The diagnostic setup and the analysis procedure can be employed for any other SP laser experiments and interferograms, respectively.
关键词： short pulse laser,optical interferometry,Mach–Zehnder interferometer,picosecond probe,plasma density
更新于2025-09-19 17:13:59
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Coupled micro-Doppler signatures of closely located targets
摘要： The classical Doppler shift originates from the movement of a target’s center of mass, but it does not hold information about the internal dynamics of the scattering object. In contrast, micro-Doppler signatures contain data about the micromotions that arise from internal degrees of freedom within the target (such as rotation and vibration), which can be remotely detected by careful analysis of the scattered ?eld. Here we investigate, both theoretically and experimentally, how coupling between a pair of closely situated targets affects the resulting micro-Doppler signatures. The presented model considers a pair of near-?eld coupled resonators with dynamically recon?gurable scattering properties. Voltage controlled varactor diodes enable modulating the scattering cross section of each target independently, mimicking rotational degrees of freedom. As a result, coupled micro-Doppler combs are observed, containing frequency components that arise from the near ?eld interactions, making it possible to extract information about the internal geometry of the system from far-?eld measurements. From a practical point of view, micro-Doppler spectroscopy allows remote classi?cation of distant objects, while deep understanding of the coupling effects on such signatures in the low frequency regime can provide valuable insight for radar and sonar systems, as well as optical and stellar radio-interferometry, among many others.
关键词： sonar,coupled resonators,stellar radio-interferometry,micro-Doppler signatures,radar,optical interferometry
更新于2025-09-16 10:30:52
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Micro Fabry-Pérot Interferometer at Rayleigh Range
摘要： The Fabry-Pérot interferometer is used in a variety of high-precision optical interferometry applications, such as gravitational wave detection. It is also used in various types of laser resonators to act as a narrow band filter. In addition, ultra-compact Fabry-Pérot interferometers are used in the optical resonators of semiconductor lasers and fiber-optic systems. In this work, we developed a micro-scale Fabry-Pérot interferometer that was constructed within the Rayleigh range of the optical focusing system. The high precision that is conventionally required for the optical parallelism and the surface accuracy of the mirrors was not so critical for this type of Fabry-Pérot interferometer. The interferometer was constructed using a gold-coated silicon microcantilever with reflectivity of 92% and a dielectric multilayer flat mirror with reflectivity of 85%. The focal spot size of the laser beam is 20 μm and the cavity length is approximately 20 μm. The finesse was measured to be approximately 25. The interferometric characteristics of the device were consistent with the theoretically calculated performance. The developed micro Fabry-Pérot interferometer has the potential to make a marked contribution to advances in optical measurements in various micro sensing system.
关键词： microcantilever,Rayleigh range,optical measurements,optical interferometry,Fabry-Pérot interferometer
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Progress on a New Measurement of von Klitzing Constant at NIM
摘要： This paper describes the progress on a new measurement of von Klitzing constant (Rk) through an experiment linking the new calculable capacitor and the quantized Hall resistance by means of a quadrature transfer at NIM. The recent improvements of the new calculable capacitor, the optical interferometry, the impedance measurement chain are presented.
关键词： von Klitzing constant,optical interferometry,bridge circuits,Calculable capacitor,impedance measurement,measurement standards
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Thermal Gradients in the Si Lattice Parameter Measurement
摘要： We report about numerical and experimental investigations of the thermal gradients in the INRIM’s combined X-ray and optical interferometer used to measure the lattice parameter of silicon.
关键词： Si lattice parameter,Avogadro constant,precision measurements,combined X-ray and optical interferometry
更新于2025-09-10 09:29:36
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Electronic wavefunctions probed by all-optical attosecond interferometry
摘要： In photoelectron spectroscopy, the ionized electron wavefunction carries information about the structure of the bound orbital and the ionic potential as well as about the photoionization dynamics. However, retrieving the quantum phase information has been a long-standing challenge. Here, we transfer the electron phase retrieval problem into an optical one by measuring the time-reversed process of photoionization—photo-recombination—in attosecond pulse generation. We demonstrate all-optical interferometry of two independent phase-locked attosecond light sources. This measurement enables us to directly determine the phase shift associated with electron scattering in simple quantum systems such as helium and neon, over a large energy range. Moreover, the strong-field nature of attosecond pulse generation resolves the dipole phase around the Cooper minimum in argon through a single scattering angle. This method may enable the probing of complex orbital phases in molecular systems as well as electron correlations through resonances subject to strong laser fields.
关键词： all-optical interferometry,electron correlations,photoelectron spectroscopy,Cooper minimum,molecular systems,electron scattering,attosecond pulse generation,quantum phase information
更新于2025-09-10 09:29:36
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Scan-Less, Kilo-Pixel, Line-Field Confocal Phase Imaging with Spectrally Encoded Dual-Comb Microscopy
摘要： Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection, and its image acquisition rate is boosted by scan-less imaging techniques. However, optical-intensity-based image contrast in CLM makes it difficult to visualize transparent non-fluorescent objects or reflective objects with nanometer unevenness. In this paper, we introduce an optical frequency comb (OFC) to scan-less CLM to give optical-phase-based image contrast. One-dimensional (1-D) image pixels of a sample are separately encoded onto OFC modes via 1-D spectral encoding by using OFC as an optical carrier of amplitude and phase with a vast number of discrete frequency channels. Then, line-field confocal information of amplitude and phase are decoded from mode-resolved OFC amplitude and phase spectra obtained by dual-comb spectroscopy. The proposed confocal phase imaging will further expand the applications of CLM.
关键词： optical interferometry,optical microscopy,Biomedical imaging
更新于2025-09-09 09:28:46
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Analytical Analysis and Experimental Validation of a Multi-parameter Mach-Zehnder Fiber Optic Interferometric Sensor
摘要： Here we report a simple analytical technique to model a Mach–Zehnder fiber optic interferometric sensors that allow us to predict and calculate via computer simulations parameters that are not easily obtained experimentally. This model was calibrated and compared with experimental data using a 120 mm sensor for measurements of temperature, refractive index and water level. For instance, we were able to calculate the effects on the cladding index caused by the variation of those physical effective parameters. Moreover, this analysis could further our understanding of such sensors and allow us to make predictions about their use in different applications and even their behavior with different sensing lengths.
关键词： optical fiber devices,analytical model,Optical fiber interference,optical fiber applications,optical interferometry
更新于2025-09-04 15:30:14