Author Affiliations
Abstract
School of Instrumentation Science & Opto-Electronics Engineering, Beihang University, Beijing 100191, China
The measurement of an extremely small magneto-optical polarization rotation angle with high sensitivity is integral to many scientific and technological applications. In this Letter, we have presented a technique based on Faraday modulation combined with the optical differential method to measure an extremely small polarization rotation angle with high sensitivity. The theoretical and experimental results show that common mode noise is reduced appreciably and signal to noise ratio is enhanced. The effectiveness of this technique has been demonstrated by measuring the Verdet constant of terbium gallium garnet glass and measuring the small polarization rotation angle. A sensitivity of enhancement of one order of magnitude has been achieved using differential detection based on Faraday modulation.
120.5410 Polarimetry 000.3110 Instruments, apparatus, and components common to the sciences 040.1880 Detection Chinese Optics Letters
2018, 16(8): 081201
Author Affiliations
Abstract
1 Institute of Particle and Two-Phase Flow Measurement/Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2 Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China
A method to three-dimensional position moving particles with one lens and two cameras is proposed. Two particle images with different degrees of defocusing are adopted to solve the ambiguous problem of particle positions. A single-lens dual-camera system is developed to simultaneously capture these two images for the moving particles. The measurement principles and theoretical analysis are introduced first, and then simulated investigations and experimental research are discussed. The measurement errors in the simulations and experiments are less than 1% and 4%, respectively, in 20 times the depth of field of the system, which validates the feasibility of this method.
120.4640 Optical instruments 110.2970 Image detection systems 000.3110 Instruments, apparatus, and components common to the sciences Chinese Optics Letters
2016, 14(3): 031201
Author Affiliations
Abstract
Core mineral spectrometer is one of the advanced and important tools for core digitalization, altered mineral mapping, ore deposits exploring, and ore-searching in surrounding mine and beneficiation process. In this letter, a new core mineral spectrometer (CMS 350) is designed and developed. The basic principle, structural design, function module, key components, data acquisition, and processing methods of CMS 350 are introduced. In addition, some applications and results of CMS 350 in Zijin Mining are presented to validate the performance of CMS 350.
300.6190 Spectrometers 000.3110 Instruments, apparatus, and components common to the sciences Chinese Optics Letters
2014, 12(8): 083002
Author Affiliations
Abstract
A method is presented for in situ resolution calibration of multiple feedback interferometers (MFIs) using two lasers with different feedback levels simultaneously. The laser with weak optical feedback level generates half-wavelength optical fringes, whereas the laser with strong multiple feedback level generates optical nano-fringes. By using this method, the number of displaced optical nano-fringes can be easily counted, and the resolution of the MFIs can be accurately determined. The integrated MFIs can be used to measure displacements and calibrate other displacement sensors.
260.3160 Interference 000.3110 Instruments, apparatus, and components common to the sciences 140.1340 Atomic gas lasers Chinese Optics Letters
2013, 11(10): 102601
Author Affiliations
Abstract
This letter presents a polarimetric interferometer (PI) that can measure the ellipsometric parameter \theta with an accuracy of 0.01o leading to a potential accuracy of 17 pm. The PI is constructed and compared with a commercial heterodyne interferometer (HI). Given its low nonlinearity, the PI is used to measure the residual nonlinearity of a heterodyne interferometric displacement system. A rotating half-wave plate is used to compensate for a part of the nonlinearity error caused by the misalignment of the axis between input polarizing states and beamsplitter.
120.2130 Ellipsometry and polarimetry 060.4370 Nonlinear optics, fibers 060.2840 Heterodyne 000.3110 Instruments, apparatus, and components common to the sciences Chinese Optics Letters
2013, 11(6): 061201
Author Affiliations
Abstract
School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China
A laser power feedback control system that features fast response, large-scale performance, low noise, and excellent stability is presented. Some essential points used for optimization are described. Primary optical lattice experiments are given as examples to show the performance of this system. With these performance characteristics, the power control system is useful for applications in cold atom physics and precision measurements.
激光功率 反馈控制 大范围 快速响应 光晶格 140.3425 Laser stabilization 020.1475 Bose-Einstein condensates 000.3110 Instruments, apparatus, and components common to the sciences Chinese Optics Letters
2011, 9(9): 091403
Author Affiliations
Abstract
Key Laboratory of Optoelectronic Technology and System, Ministry of Education, Chongqing University, Chongqing 400030, China
A multi-parameter fusion algorithm (MPFA) for auto-focus (AF) is discussed. The image sharpness evaluation algorithm (ISEA) and zoom tracking method (ZTM) are combined for AF. The zoom motor position (z) and background complexity (c) are regarded as the main parameters of this algorithm. A priority table depending on z and c is proposed. Modified ISEA or ZTM is adopted according to the priority table value. The hardware implementation of the MPFA on Texas Instruments' Davinci digital signal processor is also provided. Results show that the proposed scheme provides faster focusing compared with the conventional approaches.
图像清晰度评价 变焦跟踪算法 优先级表 000.3110 Instruments, apparatus, and components common to the sciences 040.1490 Cameras 110.2960 Image analysis 110.5200 Photography Chinese Optics Letters
2010, 8(6): 580
