scholarly journals Construction Features of The High-Precision Laser Rangefinder Light Modulator

2021 ◽  
Vol 1 (1) ◽  
pp. 26-31
Author(s):  
Yegisabet Hakob Hayrapetyan ◽  
Stepan Karen Petrosyan
Keyword(s):  
High Precision ◽  
Modulation Frequency ◽  
Modulation Method ◽  
Optical Effect ◽  
Laser Rangefinder ◽  
Light Modulator ◽  
Phase Determination ◽  
Modulation And Demodulation ◽  
Determination Error ◽  
Optical Crystal

The issues related to the development of a light modulator operating on the electro-optical effect of laser rangefinders by the modulation method are considered. To reduce the modulation power, it is proposed to lower the modulation frequency to 750-800 MHz, while simultaneously increasing the modulation quality to Q = 1000. The study of the phase determination error of a high-precision laser rangefinder depending on temperature showed that it is rational to construct the light modulator by radial installation of the KDP electro-optical crystal, with separated modulation and demodulation channels, while on combined resonators.

Design and Implementation of Digital Communication Platform Based on FPGA/DSP

2014 ◽  
Vol 981 ◽  
pp. 398-401
Author(s):  
Sheng Guo Zhou ◽  
Wen Jing Shang ◽  
Nan Wang ◽  
Victor Rublev
Keyword(s):  
Digital Communication ◽  
Software Radio ◽  
Modulation Method ◽  
Signal Process ◽  
Communication Platform ◽  
Modulation And Demodulation ◽  
Design And Implementation ◽  
Hardware System ◽  
Radio Method

A method to design and implement digital communication platform was in introduced in this paper. The platform based on software radio method can change modulation method conveniently without the change of hardware system because it used FPGA and DSP to do modulation and signal process. The QPSK modulation and demodulation was implemented in the platform to test this platform.

scholarly journals Phase-only liquid crystal spatial light modulator for wavefront correction with high precision

2004 ◽  
Vol 12 (26) ◽  
pp. 6403 ◽  
Author(s):  
Lifa Hu ◽  
Li Xuan ◽  
Yongjun Liu ◽  
Zhaoliang Cao ◽  
Dayu Li ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
High Precision ◽  
Spatial Light Modulator ◽  
Light Modulator ◽  
Wavefront Correction

High-precision laser beam shaping using a binary-amplitude spatial light modulator

2010 ◽  
Vol 49 (8) ◽  
pp. 1323 ◽  
Author(s):  
Jinyang Liang ◽  
Rudolph N. Kohn, Jr. ◽  
Michael F. Becker ◽  
Daniel J. Heinzen
Keyword(s):  
Laser Beam ◽  
High Precision ◽  
Spatial Light Modulator ◽  
Beam Shaping ◽  
Laser Beam Shaping ◽  
Light Modulator

The Construction Basis of High-Precision Optical Range Finder GD-j1(l)

2018 ◽  
Vol 931 ◽  
pp. 681-686
Author(s):  
Hovsep S. Petrosyan ◽  
Yegisabeth H. Hayrapetyan ◽  
Hovnan A. Hunanyan
Keyword(s):  
High Precision ◽  
Linear Measurement ◽  
High Accuracy ◽  
Compensation Method ◽  
Interference Method ◽  
Modulation Method ◽  
Range Finder ◽  
Optical Range ◽  
Linear Measurements ◽  
Measurement Devices

The methods of construction of high-precision rangefinder on the modulation method, which will complement the means of linear measurements on the interference method, are considered. The linearly compensation method, which leads to the possibility of implementing range finders with an error of mφ=0.01 mm, is proposed as the basic constructions of extremely high accuracy linear measurement devices.

La2SrB10O19: A Promising Ultraviolet Nonlinear Optical Crystal with an Enhanced Nonlinear Optical Effect and Shortened Cutoff Edge

2020 ◽  
Vol 20 (8) ◽  
pp. 5626-5632
Author(s):  
Jingcheng Feng ◽  
Youquan Liu ◽  
Yunfei Li ◽  
Huimin Song ◽  
Wang Liu ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Optical Effect ◽  
Nonlinear Optical Crystal ◽  
Nonlinear Optical Effect ◽  
Optical Crystal

scholarly journals Solid-State Spatial Light Modulator with Magneto-Optical Effect

2010 ◽  
Vol 38 (5) ◽  
pp. 356-362
Author(s):  
Hiroyuki TAKAGI ◽  
Pang Boey LIM ◽  
Mitsuteru INOUE ◽  
Hiromitsu UMEZAWA
Keyword(s):  
Solid State ◽  
Spatial Light Modulator ◽  
Optical Effect ◽  
Light Modulator ◽  
Magneto Optical Effect

scholarly journals High-speed spelling with a noninvasive brain–computer interface

2015 ◽  
Vol 112 (44) ◽  
pp. E6058-E6067 ◽  
Author(s):  
Xiaogang Chen ◽  
Yijun Wang ◽  
Masaki Nakanishi ◽  
Xiaorong Gao ◽  
Tzyy-Ping Jung ◽  
...  
Keyword(s):  
Information Transfer ◽  
High Speed ◽  
Target Identification ◽  
Modulation Method ◽  
Identification Algorithm ◽  
Calibration Data ◽  
Transfer Rates ◽  
Modulation And Demodulation ◽  
Individual Calibration ◽  
High Consistency

The past 20 years have witnessed unprecedented progress in brain–computer interfaces (BCIs). However, low communication rates remain key obstacles to BCI-based communication in humans. This study presents an electroencephalogram-based BCI speller that can achieve information transfer rates (ITRs) up to 5.32 bits per second, the highest ITRs reported in BCI spellers using either noninvasive or invasive methods. Based on extremely high consistency of frequency and phase observed between visual flickering signals and the elicited single-trial steady-state visual evoked potentials, this study developed a synchronous modulation and demodulation paradigm to implement the speller. Specifically, this study proposed a new joint frequency-phase modulation method to tag 40 characters with 0.5-s-long flickering signals and developed a user-specific target identification algorithm using individual calibration data. The speller achieved high ITRs in online spelling tasks. This study demonstrates that BCIs can provide a truly naturalistic high-speed communication channel using noninvasively recorded brain activities.

scholarly journals Comparison of multiple modulation techniques for various topologies of multilevel converters for single phase AC motor drive

2019 ◽  
Vol 10 (2) ◽  
pp. 662
Author(s):  
Laith M. Akram Alsaqal ◽  
Ahmed M. T. Ibraheem Alnaib ◽  
Omar Talal Mahmood
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Modulation Frequency ◽  
Harmonic Distortion ◽  
Modulation Method ◽  
Motor Drive ◽  
Comparison Study ◽  
Multilevel Converters ◽  
Performance Factors ◽  
Modulation Techniques

There are various types of Multilevel Converters (MCs) in addition to various types of modulation techniques for these types of MCs; the challenges in selecting the best one of them with regard to the amount of the required of components, and its harmonics content. So, a comparison study among these types has been done in this paper. For comparison study, the simulation of seven level of two popular topologies of MCs: Neutral Point Clamped (NPC) converter, and Cascaded-MCs were carried out with Matlab/Simulink software program. These converters are used to drive a single phase capacitor start motor drive. Multicarrier modulation control techniques are used for controlling the MCs; these techniques involve two main type: Level Shifted Carrier (LSC), and Phase Shifted Carrier (PSC). The comparison is made with respect to the performance factors as, the amplitude of  the Total Harmonic Distortion (THD), and the DC-bus utilization performance which measured by Root Mean Square of the output voltage Vrms at variable modulation indices and variable carrier frequency. Based on simulation results it's found, that the cascaded-MC with PSC modulation method gives best results, in addition to the Alternative Phase Opposition Disposition APOD-LSC modulation technique (with even number of modulation frequency) generate the output voltage with a lower harmonic content compared with the other techniques.

scholarly journals Research and Prospect on Key Technologies of Indoor Positioning Based on Visible Light Communication

2022 ◽  
Vol 2160 (1) ◽  
pp. 012074
Author(s):  
Yong Cao ◽  
Yifan Zheng ◽  
Xiao Wang ◽  
Yanbo Liu ◽  
Yi Liu
Keyword(s):  
Visible Light ◽  
High Precision ◽  
Electromagnetic Interference ◽  
Visible Light Communication ◽  
Indoor Positioning ◽  
Modulation Method ◽  
Positioning System ◽  
White Led ◽  
Wireless Positioning ◽  
Modulation Methods

Abstract Indoor positioning has become a research hotspot because of its important application value in industrial production and daily life. Traditional wireless positioning technologies such as Wi Fi and Bluetooth are difficult to achieve high-precision indoor positioning due to electromagnetic interference and multipath effect. The modulated white LED can not only meet the needs of lighting, but also transmit the location information to achieve high-precision indoor positioning. This paper first introduces several modulation methods commonly used in visible light positioning system, compares the characteristics of different modulation methods, and proposes a modulation method suitable for visible light positioning; Then, two demodulation methods of the visible light positioning system are introduced and discussed; After that, several visible light location algorithms are introduced, and the performance of each algorithm is analyzed in detail; Finally, the problems in visible light positioning are discussed and prospected.

Sign in / Sign up

Export Citation Format

Share Document