Journal ArticleDOI
Measuring the lens focal length by laser reflection-confocal technology
TLDR
LRCFM uses the peak points of confocal response curves to precisely identify the lens focus and vertex of the lens last surface and accurately measures the distance between the two positions to determine the lens focal length.Abstract:
A laser reflection-confocal focal-length measurement (LRCFM) is proposed for the high-accuracy measurement of lens focal length. LRCFM uses the peak points of confocal response curves to precisely identify the lens focus and vertex of the lens last surface. LRCFM then accurately measures the distance between the two positions to determine the lens focal length. LRCFM uses conic fitting, which significantly enhances measurement accuracy by inhibiting the influence of environmental disturbance and system noise on the measurement results. The experimental results indicate that LRCFM has a relative expanded uncertainty of less than 0.0015%. Compared with existing measurement methods, LRCFM has high accuracy and a concise structure. Thus, LRCFM is a feasible method for high-accuracy focal-length measurements.read more
Citations
More filters
Journal ArticleDOI
Implementation of digital optical phase conjugation with embedded calibration and phase rectification.
Zhipeng Yu,Meiyun Xia,Huanhao Li,Tianting Zhong,Fangyuan Zhao,Hao Deng,Zihao Li,Deyu Li,Daifa Wang,Puxiang Lai +9 more
TL;DR: This paper presents a plain yet reliable DOPC setup with an embedded four-phase, non-iterative approach that can rapidly compensate for the wavefront modulator’s surface curvature, together with a non-phase-shifting in-line holography method for optical phase conjugation in the absence of an electro-optic modulator (EOM).
Journal ArticleDOI
Corrected parabolic fitting for height extraction in confocal microscopy
TL;DR: It is demonstrated, by Monte Carlo simulations and experiments with various axial response signals with symmetrical and asymmetrical forms, that the corrected parabolic fitting algorithm has significant improvements over existing algorithms in terms of peak extraction accuracy and precision.
Journal ArticleDOI
Improved chromatic confocal displacement-sensor based on a spatial-bandpass-filter and an X-shaped fiber-coupler.
TL;DR: To improve the positioning capabilities of a chromatic confocal displacement measurement system, a super-resolving pupil filtering element (referred to as spatial-bandpass-filter), an X-shaped fiber-coupler, and a modified peak-extraction algorithm are introduced.
Journal ArticleDOI
Characterization of the displacement response in chromatic confocal microscopy with a hybrid radial basis function network.
Wenlong Lu,Cheng Chen,Jian Wang,Richard Leach,Chi Zhang,Xiaojun Liu,Lei Zili,Wenjun Yang,Xiangqian Jane Jiang +8 more
TL;DR: Using experimental tests, it is shown that the hybrid radial basis function network method significantly improves the measurement accuracy, when compared to the existing characterizing methods.
Journal ArticleDOI
High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping
TL;DR: This work presents a full-phase digital optical phase conjugation method based on off-axis holography for single-shot optical focusing through scattering media that takes advantage of the single- shot full- phase measurement while using parallel computation to quickly reconstruct the phase map.
References
More filters
Journal ArticleDOI
Measurement of focal length with phase-shifting Talbot interferometry.
TL;DR: The experimental study suggests that phase-shifting Talbot interferometry combined with a Fourier fringe analysis technique can be advantageously used to improve the accuracy of measurement.
Journal ArticleDOI
Direct determination of focal length by using Talbot interferometry.
TL;DR: A new and simple technique for the determination of the focal length of positive lenses and concave spherical surfaces by Talbot interferometry is described and it is shown that high measurement accuracy can be achieved with this technique.
Journal ArticleDOI
Laser differential reflection-confocal focal-length measurement
TL;DR: A new laser differential reflection-confocal focal-length measurement (DRCFM) method has high accuracy and strong anti-interference capability and theoretical analyses and experimental results indicate that the DRCFM relative measurement error is less than 10 ppm.
Journal ArticleDOI
Measurement of focal length of lens using phase shifting Lau phase interferometry
TL;DR: In this paper, a phase shifting Lau phase interferometry (LS-LIA) algorithm is proposed for the measurement of the focal length of a lens, which is based on the phase map interpretation.
Journal ArticleDOI
Technique for the focal-length measurement of positive lenses using Fizeau interferometry
TL;DR: This work presents what it believes is a new technique for the focal-length measurement of positive lenses using Fizeau interferometery, which utilizes the Gaussian lens equation.