Testing and Monochromatic Light Verification of Optical Path Difference Distribution of Liquid Crystal Devices Under the White Light

In this paper, we propose a fast interference spectral imaging system based on liquid crystal (LC) relaxation. The path delay of nematic LC during falling relaxation is used for the scanning of the optical path. Hyperspectral data can be obtained by Fourier transforming the data according to the path delay. The system can obtain two-dimensional spatial images of arbitrary wavelengths in the range of 300–1100 nm with a spectral resolution of 262 cm−1. Compared with conventional Fourier transform spectroscopy, the system can easily collect and integrate all valid information within 20 s. Based on the LC, controlling the optical path difference between two orthogonally polarized beams can avoid mechanical movement. Finally, the potential for application in contactless and rapid non-destructive optical component defect inspection is demonstrated.

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Determination of Optical Path Difference of White Light Fibre Interferometer Using Peak Tracking Method

Jurnal Teknologi ◽

10.11113/jt.v71.3860 ◽

2014 ◽

Vol 71 (5) ◽

Author(s):

Ley Hood Hong ◽

Asiah Yahaya ◽

Yusof Munajat

Keyword(s):

Light Source ◽

White Light ◽

Optical Path Difference ◽

Path Difference ◽

Optical Path ◽

White Led ◽

Tracking Method ◽

Peak Tracking ◽

Wavelength Resolution

The aim of this paper is to evaluate the peak tracking method for determination of optical path difference of a fibre interferometer. This study narros the scope for Mach-Zehnder configuration with neutral white LED as its light source. The peak tracking method is then applied on the interference spectrum recorded from the output port of the interferometer using a spectrometer, allowing the optical path difference to be computed. Accuracy of this method is greatly affected by the wavelength resolution of the detector, where the uncertainty of the result is smaller with higher wavelength resolution and the maximum measurable path difference was found to be about 0.6 mm.

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Automated determination of best focus and minimization of optical path difference in Linnik white light interferometry

Applied Optics ◽

10.1364/ao.50.005861 ◽

2011 ◽

Vol 50 (30) ◽

pp. 5861 ◽

Cited By ~ 5

Author(s):

Jingtao Dong ◽

Rongsheng Lu ◽

Yong Li ◽

Kui Wu

Keyword(s):

White Light ◽

Optical Path Difference ◽

Path Difference ◽

Optical Path ◽

White Light Interferometry ◽

Automated Determination

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Video-Based Interferogram Analysis for Measuring Influence of Vibration to White Light Interferometry

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.447-448.599 ◽

2010 ◽

Vol 447-448 ◽

pp. 599-603

Author(s):

Wee Keat Chong ◽

Xiang Li ◽

Sardha Wijesoma

Keyword(s):

White Light ◽

Vibration Isolation ◽

Optical Path Difference ◽

Path Difference ◽

Optical Path ◽

Isolation System ◽

Vibration Isolation System ◽

White Light Interferometer ◽

Vibration Pattern ◽

Measurement Principle

In this paper, we present a video-based interferogram analysis method for measuring the influence of vibration on white light interferometer in terms of undesired change in optical path difference between reference and sample arms. The measurement principle is based on the analysis of interferograms which involves tracking and converting change in interferograms to physical change in optical path difference. The method proposed uses the original sensor in interferometer for data acquisition as such no additional hardware is required. Such an approach ensures that the properties of interferometer such as the bandwidth of sensor are considered and the vibration pattern recorded is close to the effective influence of vibration. With our method, the influence of vibration on white light interferometer and the performance of vibration isolation system can be objectively quantified and measured.

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