MODELING AND ANALYSIS OF COMMONPATH PHASE SHIFTING SHEAR SYSTEM BASED ON BIREFRINGENT OPTICAL DEVICES

2008 ◽  
Vol 17 (04) ◽  
pp. 503-510
Author(s):  
HONGJUN WANG ◽  
ZHAO WANG ◽  
AILING TIAN ◽  
BINGCAI LIU
Keyword(s):  
Optical System ◽  
Matrix Theory ◽  
Optical Devices ◽  
Phase Shifting ◽  
Surface Measurement ◽  
Jones Matrix ◽  
Optical Surface ◽  
Modeling And Analysis ◽  
System A ◽  
Shear System

In the technology of optical surface measurement, the phase-shifting shear interferometer had been widely used. In measurement, the phase-shifting was introduced in time domain, and the measurement system adopted double optical path for change phase-shifting and shear, so the measurement accuracy was limited. To decrease error, a commonpath phase-shifting shear system based on birefringent optical devices was introduced. In this system, the lateral shear and phase-shifting 0, π/2, π, 3π/2 was introduced in the commonpath optical system. Because the birefringent optical devices can introduce shear in the collinear optical system, a new Jones matrix was established. Based on the Jones matrix theory, the principle theory was analyzed in detail. In the experiment, an optical surface was measured with this system. The theoretical analysis and experiment results demonstrate the feasibility of this approach.

scholarly journals Asymmetric Double Freeform Surface Lens for Integrated LED Automobile Headlamp

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 663
Author(s):  
Hui Zhang ◽  
Dengfei Liu ◽  
Yinwan Wei ◽  
Hong Wang
Keyword(s):  
Optical System ◽  
Design Method ◽  
Chromatic Dispersion ◽  
Electronic Devices ◽  
Color Temperature ◽  
Freeform Surface ◽  
United Nations Economic Commission ◽  
System A ◽  
Economic Commission ◽  
Key Points

We propose a design method of asymmetric double freeform surface lens for an integrated LED automobile headlamp and develop an integrated LED automobile optical system. A single asymmetric double freeform surface lens is designed to redistribute rays emitting from the light source for realizing both low and high beams. Moreover, a freeform surface reflector is used to improve the energy efficiency of high beams. The prism placed in the optical path can suppress chromatic dispersion on the edge of the target plane. Simulation and experimental results show that the illumination values and color temperature of the key points can fully meet the requirements of United Nations Economic Commission for Europe vehicle regulations (ECE) R112, 48, and 128. The volume of the whole optical system comprised of freeform surface elements is smaller than that of the low beam system of a traditional headlamp, resulting in saved space, in which other electronic devices can be installed for the safety of the driver, which indicates that the proposed method is practical in the field of automobile lighting.

scholarly journals An Error-Reduction Method for Temporal Phase Unwrapping Based on Double Three-Step Phase-Shifting and Least-Squares Fitting

2012 ◽  
Vol 6-7 ◽  
pp. 76-81
Author(s):  
Yong Liu ◽  
Ding Fa Huang ◽  
Yong Jiang
Keyword(s):  
Least Squares ◽  
Reduction Method ◽  
Intermediate Phase ◽  
Error Reduction ◽  
Phase Unwrapping ◽  
Phase Shifting ◽  
Surface Measurement ◽  
Acquisition Time ◽  
Least Squares Fitting ◽  
Temporal Phase

Phase-shifting interferometry on structured light projection is widely used in 3-D surface measurement. An investigation shows that least-squares fitting can significantly decrease random error by incorporating data from the intermediate phase values, but it cannot completely eliminate nonlinear error. This paper proposes an error-reduction method based on double three-step phase-shifting algorithm and least-squares fitting, and applies it on the temporal phase unwrapping algorithm using three-frequency heterodyne principle. Theoretical analyses and experiment results show that this method can greatly save data acquisition time and improve the precision.

Otoscopy and Photography

1979 ◽  
Vol 88 (6) ◽  
pp. 771-773 ◽  
Author(s):  
Benjamin Chen ◽  
Terry L. Fry ◽  
Newton D. Fischer
Keyword(s):  
Light Source ◽  
Clinical Application ◽  
Middle Ear ◽  
Optical System ◽  
Strobe Light ◽  
System A ◽  
The Subject ◽  
Ear Canals ◽  
Light Color ◽  
Otoscopic Examination

A new hand-held otoscope photographic system, convenient and suitable for clinical application, is introduced. This instrument allows clear otoscopic examination in stenotic or tortuous ear canals, and photographs the subject in one procedure. The instrument consists of a rodlens optical system, a fiberoptic light source, a camera, and exchangeable speculum and a strobe light. Color photographs of tympanic membranes and middle ear pathology are presented.

4D cone beam CT phase sorting using high frequency optical surface measurement during image guided radiotherapy

2011 ◽  
Author(s):  
G. J. Price ◽  
T. E. Marchant ◽  
J. M. Parkhurst ◽  
P. J. Sharrock ◽  
G. A. Whitfield ◽  
...  
Keyword(s):  
High Frequency ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Surface Measurement ◽  
Optical Surface ◽  
Image Guided Radiotherapy ◽  
Image Guided

Double Closed-Loop Motor Modeling and Analysis for Lunar Rover Simulation

2012 ◽  
Vol 472-475 ◽  
pp. 1971-1976 ◽  
Author(s):  
Wei Dong Huang ◽  
Hong Kui Feng ◽  
Jin Song Bao ◽  
You Sheng Xu
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Dynamics Simulation ◽  
Motor Drive ◽  
Modeling And Analysis ◽  
Lunar Rover ◽  
System A ◽  
Drive Control ◽  
Body Dynamics ◽  
Multi Body

Motor drive control is the major study field in the development of lunar rover. Based on the double-closed DC loop adjustable-speed system, a motor drive simulation module using a position recursive PID control algorithm is developed, which is integrated into the multi-body dynamics simulation system, to carry out the whole lunar rover simulation. And the cruise process of lunar rover locomotion in the complex lunar terrain is simulated in a virtual environment.

A NEW METHOD OF LENS CENTERING IN THE OPTICAL SYSTEM BY USING SPECIAL MOUNT

2021 ◽  
pp. 137-144
Author(s):  
Bao Bui Dinh
Keyword(s):  
Optical System ◽  
Optical Axis ◽  
Assembly Process ◽  
Optical Surface ◽  
Lens System ◽  
High Quality ◽  
Manufacturing Equipment ◽  
Influence Coefficients ◽  
Process Solutions

Decentration in lens systems (for example objectives) significantly degrades the quality of image, such as the coma. In order to reduce lens decentration, the lenses are centered while manufacturing, while gluing, while attachment in the mounts. Significant decrease in the lenses decentering in the mounts is achieved by using a special manufacturing equipment, which allow combining the optical axis of the lens with the base axis of the mount in assembly process. Solutions for coma's alignment by shifting, tilting and rotation their components are also provided in the construction of high-quality objectives (microscopes [1-7], photolithographic, aerophotographic). For optimization of methods for such adjustment the influence coefficients of decentering of each optical surface of the lens system on the value and sign of coma must be calculated and taken into account. In this paper, we propose a special mounting which combined with the Opticentric of Trioptics device to center the lenses. The results show that the decentering is significantly reduced (0.9µm) compared to (44.2µm) with using a reference mount.

Motion-picture phase imaging by an integrated optical system of a parallel phase-shifting digital holographic microscope

2018 ◽  
Author(s):  
Kazuki Shimizu ◽  
Yasuhiro Awatsuji ◽  
Kenzo Nishio ◽  
Osamu Matoba ◽  
Takahito Fukuda ◽  
...  
Keyword(s):  
Motion Picture ◽  
Optical System ◽  
Phase Shifting ◽  
Phase Imaging ◽  
Integrated Optical
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