High-Speed Swept Laser Source Based on Optical Buffer Device Within Ring Cavity

2020 ◽  
Vol 57 (1) ◽  
pp. 011407
Author(s):  
方定江 Fang Dingjiang ◽  
童杏林 Tong Xinglin ◽  
张翠 Zhang Cui ◽  
邓承伟 Deng Chengwei ◽  
汪鹏飞 Wang Pengfei
Keyword(s):  
High Speed ◽  
Ring Cavity ◽  
Laser Source ◽  
Optical Buffer

A High Speed and Ultra Long-Haul Radio-Over-Fiber System Employing Dual Photoelectric Arms Coherent Modulation and Optical Duo-Binary Coding

2014 ◽  
Vol 988 ◽  
pp. 544-547
Author(s):  
Guang Li
Keyword(s):  
High Speed ◽  
Continuous Wave ◽  
Single Mode ◽  
Fiber Amplifier ◽  
Radio Over Fiber ◽  
Laser Source ◽  
Signal Spectrum ◽  
Fiber System ◽  
Binary Coding ◽  
Coherent Modulation

A novel high speed and ultra long-haul radio-over-fiber (ROF) system based on Dual Photoelectric Arms Coherent Modulation (DPACM) and Optical Duo-Binary Coding (ODBC) is proposed, and demonstrated. The signal spectrum bandwidth, generated by ODBC based on the first order DPACM, is half of non-return-to-zero (NRZ ) signal spectrum bandwidth. The secondary order DPACM generates a 40-GHz Millimeter-wave (mm-wave) that is transmitted over fiber (ROF). The simulation results show that, the bit rate can be up to 40 Gbps and the transmission distance is over 1500 Km, based on the ROF system with a 0 dBm continuous-wave laser source, multiple stages Er-Doped Fiber Amplifier (EDFA), a standard single mode fiber (SSMF) with a dispersion of 17 ps/nm/Km and a attenuation of 0.2 dB/Km.

An all-fiber self-mixing range finder with tunable fiber ring cavity laser source

2020 ◽  
pp. 1-1
Author(s):  
Yunkun Zhao ◽  
Chenchen Wang ◽  
Yuanyang Zhao ◽  
Desheng Zhu ◽  
Liang Lu
Keyword(s):  
Ring Cavity ◽  
Laser Source ◽  
Range Finder ◽  
Fiber Ring ◽  
Cavity Laser

scholarly journals Design for a Highly Stable Laser Source Based on the Error Model of High-Speed High-Resolution Heterodyne Interferometers

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1083
Author(s):  
Hongxing Yang ◽  
Ziqi Yin ◽  
Ruitao Yang ◽  
Pengcheng Hu ◽  
Jing Li ◽  
...  
Keyword(s):  
Measurement Error ◽  
High Resolution ◽  
High Speed ◽  
Beat Frequency ◽  
Error Model ◽  
Laser Source ◽  
Measurement Error Model ◽  
High Resolution Measurement ◽  
Resolution Measurement ◽  
The Impact

Heterodyne interferometers with two opposite Doppler shift interference signals have been proposed for high-resolution measurement with high measurement speed, which can be used in the background of high-speed high-resolution measurement. However, a measurement error model for high-speed high-resolution heterodyne interferometers (HSHR-HIs) has not yet been proposed. We established a HSHR-HI measurement error model, analyzed the influence of beat frequency stability with a simplified optical structure, and then designed an offset-locked dual-frequency laser source with a digital control system to reduce the impact of beat frequency drift. Experiments were used to verify the correction of the measurement error model and the validity of the laser source. The results show that the new laser source has a maximum beat frequency range of 45 MHz, which shows the improvements in the measuring speed and resolution.

scholarly journals High Speed, Localized Multi-Point Strain Measurements on a Containment Vessel at 1.7 MHz Using Swept-Wavelength Laser-Interrogated Fiber Bragg Gratings

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5935
Author(s):  
Steve Gilbertson ◽  
Mark Pickrell ◽  
Dario Castano ◽  
Gary Salazar ◽  
Tom Beery ◽  
...  
Keyword(s):  
Strain Measurement ◽  
High Speed ◽  
High Explosive ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Laser Source ◽  
Global Changes ◽  
Element Analysis ◽  
All Optical ◽  
Explosive Detonation

Dynamic elastic strain in ~1.8 and 1.0 m diameter containment vessels containing a high explosive detonation was measured using an array of fiber Bragg gratings. The all-optical method, called real-time localized strain measurement, recorded the strain for 10 ms after detonation with additional measurements being sequentially made at a rate of 1.7 MHz. A swept wavelength laser source provided the repetition rate necessary for such high-speed measurements while also providing enough signal strength and bandwidth to simultaneously measure 8 or more unique points on the vessel’s surface. The data presented here arethen compared with additional diagnostics consisting of a fast spectral interferometer and an optical backscatter reflectometer to show a comparison between the local and global changes in the vessel strain, both dynamically and statically to further characterize the performance of the localized strain measurement. The results are also compared with electrical resistive strain gauges and finite element analysis simulations.

Frequency Response Bandwidth Calibration of High Speed Photodetector Using Frequency-Stabilized Laser by Optical Heterodyne Technique

2014 ◽  
Vol 644-650 ◽  
pp. 1031-1034
Author(s):  
Nan Xu ◽  
Jian Wei Li ◽  
Jian Li ◽  
Zhi Xin Zhang
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Beat Frequency ◽  
Tunable Laser ◽  
Laser Source ◽  
Response Measurement ◽  
System A ◽  
Response Bandwidth ◽  
Heterodyne Technique ◽  
Frequency Stabilized Laser

In this paper, frequency-stabilized laser technology is introduced into photodetector frequency response measurement system. A 1531nm frequency-stabilized laser fulfilled by acetylene saturated absorption is employed to produce coherent light with a tunable laser source, gaining stable beat frequency light that reaches as high as several hundred ghz, fulfilling measurement of 40ghz high-speed photodetector frequency response bandwidth, and lowering impacts caused by instability of light frequency. In addition, measurement uncertainty analysis is conducted, which is better than 7 %(k=2).

Research on the High-Speed Object Shadowgraph Image Processing Method Based on Adaptive Threshold Segmentation

2013 ◽  
Vol 325-326 ◽  
pp. 1571-1575
Author(s):  
Fang Wang ◽  
Zong Wei Yang ◽  
De Ren Kong ◽  
Yun Fei Jia
Keyword(s):  
Image Processing ◽  
High Speed ◽  
Center Of Mass ◽  
Image Data ◽  
Ccd Camera ◽  
Adaptive Threshold ◽  
Processing Method ◽  
Laser Source ◽  
Feature Points ◽  
Threshold Segmentation

Shadowgraph is an important method to obtain the flight characteristics of high-speed object, such as attitude and speed etc. To get the contour information of objects and coordinates of feature points from shadowgraph are the precondition of characteristics analysis. Current digital shadowgraph system composed of CCD camera and pulsed laser source is widely used, but still lack of the corresponding method in image processing. Therefore, the selection of an effective processing method in order to ensure high effectiveness and accuracy of image data interpretation is an urgent need to be solved. According to the features of shadowgraph, a processing method to realize the contour extraction of high-speed object by adaptive threshold segmentation is proposed based on median filtering in this paper, and verified with the OpenCV in VC environment, the identification process of the feature points are recognized. The result indicates that by using this method, contours of high-speed objects can be detected nicely, to combine relevant algorithm, the pixel coordinates of feature points such as the center of mass can be recognized accurately.

Effect of Optical Properties Characteristic Polymethylmethacrylate Using UV Laser Direct-Structuring

2014 ◽  
Vol 939 ◽  
pp. 230-236
Author(s):  
Chien Kai Chung ◽  
Wen Tse Hsaio ◽  
Shih Feng Tseng ◽  
Kuo Cheng Huang ◽  
Ming Fei Chen
Keyword(s):  
High Speed ◽  
Pulse Repetition Frequency ◽  
Laser System ◽  
3D Structure ◽  
Optical Quality ◽  
Light Transmittance ◽  
Laser Source ◽  
Laser Machining ◽  
Uv Laser ◽  
Machining Quality

Polymethylmethacrylate (PMMA) material has excellent characteristics, such as being light weight, low cost, ease of machining, and optical quality, which are useful in numerous applications such as backlit LCD display panels, lens optics, and other photoelectric fields. Laser machining of polymerization material results in a superior machining quality, high accuracy, high speed, and high reproducibility, produces a small variety of products, reduces mold costs, and enables the rapid manufacture of products based on complex graphics by processing different depths and widths of the 3D structure. This paper presents the fabrication of symmetrical array microstructures on PMMA material by using a UV laser system. The PMMA material dimensions and thickness were 20 x 20 mm and 1 mm, respectively. Regarding the machining quality, the laser pulse energy, pulse repetition frequency, and fill spacing were adjusted. For the experiments, a semiconductor laser source (635 nm/5 mW/TEM00) and a beam profiler were used to measure the characteristics of a laser beam passing through the microstructures. The microstructure pitches and morphologies also affected the light uniformity. After laser machining, the surface morphology and the light transmittance were measured using a spectrophotometer.

scholarly journals Active meta polarizer for terahertz frequencies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hang Wong ◽  
Kai Xu Wang ◽  
Laure Huitema ◽  
Aurelian Crunteanu
Keyword(s):  
High Speed ◽  
Phase Change Materials ◽  
High Efficiency ◽  
Low Cost ◽  
Single Layer ◽  
Intense Laser ◽  
Laser Source ◽  
Terahertz Waves ◽  
Compact Size ◽  
Thz Waves

Abstract Active meta polarizers based on phase-change materials have recently led to emerging developments in terahertz devices and systems for imaging, security, and high-speed communications. Existing technologies of adaptive control of meta polarizers are limited to the complexity of external stimuli. Here, we introduce an active terahertz polarizer consisting of a single layer of large array patterns of vanadium dioxide material integrated with metallic patch matrix to dynamically reconfigure the polarization of the terahertz waves. The proposed active polarizer is simple in structure and can independently manipulate the polarization of the incident THz waves in two orthogonal directions. In addition, the device can also be performing as a highly efficient reflector at the same frequencies. We demonstrate that efficient and fast polarization changes of THz waves can be achieved over a wide operating bandwidth. Compared with other active polarizers using mechanical, optical and thermal controls, it can be conveniently manipulated with DC bias without any external actuators, intense laser source or heater. Therefore, with the advantages of high efficiency, compact size, low loss, low cost and fast response, the proposed polarizer can be highly integrative and practical to operate within adaptive terahertz circuits and systems.

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