Study of the Vernier Effect Based on the Fabry–Perot Interferometer: Methodology and Application

The optical Vernier effect is a powerful tool for improving the sensitivity of an optical sensor, which relies on the use of two sensor units with slightly detuned frequencies. However, an improper amount of detuning can easily cause the Vernier effect to be unusable. In this work, the effective generation range of the Vernier effect and the corresponding interferometer configuration are suggested and experimentally demonstrated through a tunable cascaded Fabry–Perot interferometer structure. We further demonstrate a practical method to increase the magnification factor of the Vernier effect based on the device bandwidth. Only the optical path length of an interferometer probe and the sensitivity of the measurement parameters are needed to design this practical interferometer based on the Vernier effect. Our results provide potential insights for the sensing applications of the Vernier effect.

Download Full-text

Accurate and Fast Estimation of Optical Properties Using Optical Path Length and Spatially Resolved Reflectance Measurement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.222.318 ◽

2011 ◽

Vol 222 ◽

pp. 318-321 ◽

Cited By ~ 2

Author(s):

Takayuki Yamashita ◽

Masatsugu Niwayama ◽

Toshitaka Yamakawa

Keyword(s):

Optical Properties ◽

Light Intensity ◽

Path Length ◽

Continuous Wave ◽

Practical Method ◽

Optical Path Length ◽

Optical Path ◽

Phase Detector ◽

Reflectance Measurement ◽

Spatially Resolved

We developed a new practical method for determining the absorption coefficient and reduced scattering coefficient simultaneously by using the spatial light intensity profile and the optical path length based on the results of a Monte Carlo simulation. The proposed system is optically and electrically robust and practical because (1) light intensity detection of a continuous wave for the spatially resolved reflectance is stable, convenient, and fast, and (2) the optical path length calculated from the phase can be measured precisely using the digital phase detector of a laser rangefinder. The optical properties of the tissue-like medium were measured accurately and quickly.

Download Full-text

Miniature Twist/Rotation Fabry Perot Sensor Based on a Four-Core Fiber

Proceedings ◽

10.3390/proceedings2131091 ◽

2018 ◽

Vol 2 (13) ◽

pp. 1091

Author(s):

Vedran Budinski ◽

Denis Donlagic

Keyword(s):

Path Length ◽

Optical Path Length ◽

Optical Path ◽

Glass Capillary ◽

Rotation Sensor ◽

Reflective Mirror ◽

Fabry Perot ◽

The Individual ◽

Optical Paths ◽

Multicore Fiber

This paper presents a miniature Fabry Perot twist/rotation sensor. The presented sensor consists of a single lead-in multicore fiber, which has four eccentrically positioned cores, a special asymmetrical microstructure, similar to a truncated cylinder, and an inline semi reflective mirror, all packed in a glass capillary housing. The perpendicular cut lead-in multicore fiber and the inline semi reflective mirror form four Fabry-Perot cavities. The optical path length of each Fabry-Perot interferometer is defined by the distance between mirrors, refractive index and twist/rotation angle of the microstructure in relation to the core positions in the lead in multicore fiber. Optical paths of Fabry-Perot Interferometers are modulated by a structure’s twist/rotation, change of structure length, or change of temperature. Each of these parameters modulate the optical path length of the individual interferometers in their own separate fashion, thus allowing independent measurements of twist/rotation, length/strain and temperature.

Download Full-text

Symmetric nonconfocal Fabry–Perot cavity with a stable long optical path length and improved tolerance for angular alignment

Optical Engineering ◽

10.1117/1.oe.60.12.125107 ◽

2022 ◽

Vol 60 (12) ◽

Author(s):

Dong-Jin Lee ◽

Beom-Hoan O

Keyword(s):

Path Length ◽

Optical Path Length ◽

Optical Path ◽

Fabry Perot

Download Full-text

Automatic Control of Optical Path Length for Improving Power of Pulse Fiber Lasers

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.139.113 ◽

2019 ◽

Vol 139 (1) ◽

pp. 113-118

Author(s):

Ryo Amano ◽

Minoru Yoshida

Keyword(s):

Automatic Control ◽

Fiber Lasers ◽

Path Length ◽

Optical Path Length ◽

Optical Path

Download Full-text

Investigation of particulate systems using optical pathlength spectroscopy

MRS Proceedings ◽

10.1557/proc-627-bb1.6 ◽

2000 ◽

Vol 627 ◽

Author(s):

Gabriel Popescu ◽

Aristide Dogariu

Keyword(s):

Path Length ◽

Random Media ◽

Michelson Interferometer ◽

Industrial Process ◽

Optical Path Length ◽

Industrial Applications ◽

Optical Path ◽

Interference Signal ◽

Optical Length ◽

Reference Mirror

ABSTRACTIn many industrial applications involving granular media, knowledge about the structural transformations suffered during the industrial process is desirable. Optical techniques are noninvasive, fast, and versatile tools for monitoring such transformations. We have recently introduced optical path-length spectroscopy as a new technique for random media investigation. The principle of the method is to use a partially coherent source in a Michelson interferometer, where the fields from a reference mirror and the sample are combined to obtain an interference signal. When the system under investigation is a multiple-scattering medium, by tuning the optical length of the reference arm, the optical path-length probability density of light backscattered from the sample is obtained. This distribution carries information about the structural details of the medium. In the present paper, we apply the technique of optical path-length spectroscopy to investigate inhomogeneous distributions of particulate dielectrics such as ceramics and powders. The experiments are performed on suspensions of systems with different solid loads, as well as on powders and suspensions of particles with different sizes. We show that the methodology is highly sensitive to changes in volume concentration and particle size and, therefore, it can be successfully used for real-time monitoring. In addition, the technique is fiber optic-based and has all the advantages associated with the inherent versatility.

Download Full-text

Stray light characterization with ultrafast time-of-flight imaging

Scientific Reports ◽

10.1038/s41598-021-89324-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

L. Clermont ◽

W. Uhring ◽

M. Georges

Keyword(s):

Path Length ◽

Imaging System ◽

Time Of Flight ◽

Optical Path Length ◽

Optical Path ◽

Stray Light ◽

Laser Source ◽

Space Telescopes ◽

Characterization Methods ◽

Instance Space

AbstractUnderstanding stray light (SL) is a crucial aspect in the development of high-end optical instruments, for instance space telescopes. As it drives image quality, SL must be controlled by design and characterized experimentally. However, conventional SL characterization methods are limited as they do not provide information on its origins. The problem is complex due to the diversity of light interaction processes with surfaces, creating various SL contributors. Therefore, when SL level is higher than expected, it can be difficult to determine how to improve the system. We demonstrate a new approach, ultrafast time-of-flight SL characterization, where a pulsed laser source and a streak camera are used to record individually SL contributors which travel with a specific optical path length. Furthermore, the optical path length offers a means of identification to determine its origin. We demonstrate this method in an imaging system, measuring and identifying individual ghosts and scattering components. We then show how it can be used to reverse-engineer the instrument SL origins.

Download Full-text

Measurement of the effective optical path length of diffusing integrating cavities using time-resolved spectroscopy

Applied Optics ◽

10.1364/ao.57.003519 ◽

2018 ◽

Vol 57 (13) ◽

pp. 3519 ◽

Cited By ~ 1

Author(s):

Xue Zhou ◽

Jia Yu ◽

Lin Wang ◽

Zhiguo Zhang

Keyword(s):

Path Length ◽

Optical Path Length ◽

Optical Path ◽

Time Resolved ◽

Time Resolved Spectroscopy ◽

Effective Optical Path Length

Download Full-text

Non-Traditional Applications of near Infrared Spectroscopy Based on the Optical Characteristic Models for a Biological Material Having Cellular Structure

Journal of Near Infrared Spectroscopy ◽

10.1255/jnirs.119 ◽

1998 ◽

Vol 6 (1) ◽

pp. 41-46 ◽

Cited By ~ 6

Author(s):

Satoru Tsuchikawa

Keyword(s):

Biological Material ◽

Path Length ◽

Cellular Structure ◽

Process Model ◽

Near Infrared ◽

Traditional Approach ◽

Nir Spectroscopy ◽

Optical Path Length ◽

Optical Path ◽

The Mean

Non-destructive measurements, based on near infrared (NIR) spectroscopy, on biological material with a cellular structure like wood require a non-traditional approach. We have developed new concepts to model the optical properties of a sample having cellular structure, for the illumination conditions of the spectrometer available to us. A set of optical models, which consisted of the directional characteristics models, the light-path models and the equivalent surface roughness model was proposed to clarify the behaviour of light propagation in a wood sample. Furthermore, the mean optical path length, which was derived by incorporating the nth power cosine model of radiant intensity into the diffusion process model in consideration of the parallel beam component of incident light, was calculated. By introducing the concept of equivalent sample thickness, compatible with the mean optical path length, into the Kubelka–Munk theory, generalised input/output equations for radiation were constructed. In this non-traditional application of NIR spectroscopy, these optical concepts make it possible to analyse both the physical condition and chemical composition of a biological material with a cellular structure.

Download Full-text