Virtual Issue
- Abstract：
According to the requirements of all optical networks and high speed optical time division multiplex systems for the time delay adjustment, a novel tunable ∝-type delay line is proposed based on the optical fiber nonlinear effect. The delay line is consist of some all-fiber-type devices, such as special optical fibers, optical fiber gratings, and optical fiber amplifiers. On the self-phase modulation, group-velocity dispersion effect and the light splitting effect, the delay line obtains the flat broadened Keywords：all-optical delay line;tunable delay line;optical fiber nonlinear effect;flat broadened spectrum;dispersion;all-optical network;time division multiplexing477|868|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
The stiffness measurement precision of an optical trap is a key in optical force measurement, so this paper proposes a method based on Boltzmann statistics to analyze the stiffness measurement precision of the optical trap. Firstly, a near infrared optical tweezer was introduced and it was built on an air cushion platform in a dark room to isolate light interference and vibration interference. Then, a quadrant photodiode was used to detect the backscatter light of a microsphere captured by the tweezer and t Keywords：optical tweezer;near-infrared optical tweezer system;optical trap stiffness measurement;Boltzmann statistics method422|826|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
As the non-equivalence of absolute radiometers has complex sources and it is difficult to be measured, this paper proposes the finite element method to correct the non-equivalence of a Solar Irradiance Absolute Radiometer (SIAR).On the basis of the measuring method the SIAR, the nonlinear thermal dynamic response of the cavity in vacuum was tested. A finite element model with a relative error of 0.14% for an experimental cavity was established based on the finite element method to test the temperature respo Keywords：Solar Irradiance Absolute Radiometer(SIAR);finite element method;non-equivalence;temperature response336|577|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
A new monocentric multiscale imaging system with a wide field of view and dual resolution was proposed based on the theories of monocentric multiscale imaging and foveated imaging to achieve the high resolution dynamic gazing of the interesting region in a wide-area. The working model of this system was described in detail. By using a single lens and a doublet as the initial structure, two axis MEMS(Micro-Electronic-Mechanical System) micro mirrors were combined to form a light path. On the basis of the ZEM Keywords：monocentric multiscale imaging system;foveated imaging;dual resolution imaging;MEMS micro mirror;high resolution dynamic gazing;wide field of view332|1288|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
When the differential image motion monitor method is used to measure the atmospheric coherence length, it needs a number of frames recorded with objective motions. Therefore, this paper proposes a simultaneous measuring method of the atmospheric coherence length based on the wavefront structure function for spatial objective. The method uses a Shack-Hartmann wavefront sensor to measure the Zernike coefficients of a frame of aberrated wavefront with short exposure. Then, it subtracts the initial aberration o Keywords：adaptive optics;atmospheric coherence length;spatial objective;simultaneous measurement;wavefront structure function method454|937|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
An ultra high speed CCD driver timing method based on a normal CCD image sensor was proposed to improve the CCD image acquisition speed and achieve the image speed in million frame per second. The working processing of the CCD after masking was introduced. With a specialized mask, the original light sensitive area of the normal CCD sensor was divided into pixel array with a certain storage area to implement the storage function on a chip. The driver timing method to achieve the image speed in million frame Keywords：million frame per second imaging;CCD driver timing;high frame rate imaging system;Charge Couple Device(CCD)352|549|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
The auto-focusing precision of microscopy has great influence on the performance of machine-vision-based precise measurement. A comprehensively quantitative evaluation method on image auto-focusing technique in a microscopic vision environment was researched. Several kinds of evaluation indexes were proposed, and the unbiasedness, unimodality, spatial resolution etc. of 13 groups sharpness functions were comprehensively evaluated in a microscopic vision condition. Then variance function and Brenner function Keywords：machine vision;microscopic imaging;auto-focusing;microassembly;Micro-electro-mechanical System(MEMS);comprehensively quantitative evaluation457|749|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
When CaF2 materials are used in projection lenses, the performance of the projection lenses can be improved greatly. This paper researches the process of CaF2 crystal fabrication to realize its high precision optical fabrication in all wave bands. Firstly, the pitch lap and the diamond powder were used to get a relative better figure and surface quality of a CaF2 element. Then, the technological parameters of the polishing lap, such as rotation speed, movement range and pressure were optimized, and the coll Keywords：CaF2;projection lens;precision optical fabrication;sub-nanometer precision fabrication;Ion Beam Figuring(IBF)778|1624|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
Based on Giant Magnetostritive Materials(GMMs), a novel GMM-FBG (Fiber Brager Grating) current sensor with automatic temperature compensation is proposed by combing a sensing fiber Bragg grating (S-FBG) and an auxiliary fiber Bragg grating (A-FBG). The sensor cascades the S-FBG and the A-FBG and pasts them crossly on the GMM bars, then puts them into a magnetic circuit consisted of the ferrites. The radial direction of S-FBG is controlled the same as the direction of magnetic field, and that of the A-FBG is Keywords：optical fiber current sensor;Fiber Bragg Grating(FBG);Giant Magnetostrictive Material(GMM);temperature compensation337|1034|0<HTML><L-PDF>Updated：2020-07-16 - Abstract：
To evaluate quantitatively the uniformity of image illumination for an On-line Visual Ferrograph (OLVF)imaging system, a new mathematical model of image illumination was presented. The view field of an object space was represented by image space parameters and optical magnification, then it was discretized into a micro area. By taking Lambert-cosine law as reference, the image illumination model based on the aperture of entrance pupil was established, the image illumination distribution was calculated relia Keywords：On-line Visual Ferrograph(OLVF);imaging system;Light Emitting Diode(LED);illumination uniformity;image illumination model;image uniformity evaluation411|672|0<HTML><L-PDF>Updated：2020-07-16
