Optical path length control in plasma absorption measurements

2002 ◽  
Vol 73 (7) ◽  
pp. 2578-2582 ◽  
Author(s):  
Brett A. Cruden ◽  
M. V. V. S. Rao ◽  
Surendra P. Sharma ◽  
M. Meyyappan
Keyword(s):  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Plasma Absorption ◽  
Path Length Control ◽  
Absorption Measurements

Finite Element Modeling of Optical Path Length Control Device for Laser Gyroscope

2014 ◽  
Vol 496-500 ◽  
pp. 1169-1175
Author(s):  
Xu Dong Yu ◽  
Yuan Pin Xie ◽  
Peng Fei Zhang ◽  
Guang Feng Lu ◽  
Yu Nong Xu ◽  
...  
Keyword(s):  
Finite Element ◽  
Path Length ◽  
Structural Parameters ◽  
Optical Path Length ◽  
Control Device ◽  
Optical Path ◽  
Response Analysis ◽  
Laser Gyroscope ◽  
Simulation Results ◽  
Path Length Control

Optical path length variations due to temperature, manufacturing misalignments, operation environments can affect the performance of ring laser gyroscope (RLG). This paper presents a structural design of optical path length control device (PLC) using finite element analysis. The static analysis and harmonic response analysis of the PLC is performed to investigate the deformation on different voltage, and model analysis is selected to determine the natural frequency and eigenmodes. To validate the simulation results, an experiment on RLG with mode-scanning is carried out and the maximum errors are within 0.025um. The experiment results are found to be in good agreement with the simulation results. The results indicate that the finite element model can be beneficial to designing and optimizing the structural parameters for the PLC.

High-Speed Mechanical Actuator for Precision Optical Path Length Control

2009 ◽  
Vol 48 (1) ◽  
pp. 010212 ◽  
Author(s):  
Kosuke Machida ◽  
Shigenori Moriwaki ◽  
Norikatsu Mio
Keyword(s):  
Path Length ◽  
High Speed ◽  
Optical Path Length ◽  
Optical Path ◽  
Path Length Control

Investigation of particulate systems using optical pathlength spectroscopy

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.

scholarly journals Stray light characterization with ultrafast time-of-flight imaging

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.

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

1998 ◽  
Vol 6 (1) ◽  
pp. 41-46 ◽  
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.

Electric-field-induced optical path length change in LiNbO3:MgO crystals: spatial anisotropy analysis

2013 ◽  
Vol 52 (16) ◽  
pp. 3757 ◽  
Author(s):  
Anatoliy S. Andrushchak ◽  
Oleh V. Yurkevych ◽  
Bogdan M. Strychalyuk ◽  
Mykhailo M. Klymash ◽  
Andrzej Rusek ◽  
...  
Keyword(s):  
Electric Field ◽  
Path Length ◽  
Length Change ◽  
Optical Path Length ◽  
Optical Path ◽  
Spatial Anisotropy
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