scholarly journals Investigation of Spatial Chirp Induced by Misalignments in a Parallel Grating Pair Pulse Stretcher

2020 ◽  
Vol 10 (5) ◽  
pp. 1584 ◽  
Author(s):  
Zhicheng Zhong ◽  
Wenqi Gong ◽  
Hao Jiang ◽  
Honggang Gu ◽  
Xiuguo Chen ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Simulation Method ◽  
Output Pulse ◽  
Imaging Spectrometer ◽  
Chirped Pulse ◽  
Adjustment Procedure ◽  
Simulation Results ◽  
Spatial Chirp ◽  
Ray Tracing Simulation ◽  
Grating Pair

Spatial chirp induced by the misaligned gratings and mirrors in a parallel grating pair pulse stretcher can significantly affect the performance of the output pulses. Firstly, a detailed analysis about the spatial chirp of the stretched pulses caused by the misalignments has been carried out using the ray tracing simulation method. According to the simulation results, an adjustment procedure has been summarized to accurately calibrate these misalignments. The proposed method has been successfully applied in a home-made chirped pulse stretcher. By measuring the output pulse with an imaging spectrometer, the results show the stretched pulse has a good linear temporal chirp and little spatial chirp, which demonstrates the good adjustment of the stretcher.

Influence of surface relaxation on the contrast of threading edge dislocations in synchrotron X-ray topographs under the condition of g · b = 0 and g · b × l = 0

2021 ◽  
Vol 54 (2) ◽  
Author(s):  
Hongyu Peng ◽  
Tuerxun Ailihumaer ◽  
Fumihiro Fujie ◽  
Zeyu Chen ◽  
Balaji Raghothamachar ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Depth Profiling ◽  
Simulation Method ◽  
Surface Relaxation ◽  
X Ray ◽  
Relaxation Effects ◽  
Orientation Contrast ◽  
Relaxation Depth ◽  
Edge Dislocations ◽  
Ray Tracing Simulation

Residual contrast of threading edge dislocations is observed in synchrotron back-reflection X-ray topographs of 4H-SiC epitaxial wafers recorded using basal plane reflections where both g · b = 0 and g · b × l = 0. The ray-tracing simulation method based on the orientation contrast formation mechanism is applied to simulate images of such dislocations by applying surface relaxation effects. The simulated contrast features match the observed features on X-ray topographs, clearly demonstrating that the contrast is dominated by surface relaxation. Depth profiling indicates that the surface relaxation primarily takes place within a depth of 5 µm below the surface.

VLC-LED Receiver Condenser with Optimized CPC

2014 ◽  
Vol 597 ◽  
pp. 480-483
Author(s):  
Zhao Xia Wu ◽  
You Jin Nie ◽  
Wei Jin ◽  
Zhi Xu Zhang ◽  
Qian Qiao ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ray Tracing ◽  
Signal Intensity ◽  
Concentration Ratio ◽  
Deviation Angle ◽  
Compound Parabolic Concentrator ◽  
Simulation Results ◽  
Ray Tracing Simulation

In order to enhance the signal intensity of VLC-LED receiver, this paper describes a receiver condenser which is designed based on optimized CPC (compound parabolic concentrator) by using a truncated method, for achieving the aim of boosting receiver’s ability of gathering light and enhancing signal intensity. The Monte Carlo-ray tracing simulation results shows that in the VLC-LED system, the optimized CPC condenser has those advantages, such as higher concentration ratio, larger concentrate light deviation angle.

scholarly journals Homogeneous Flux Distribution in High-Flux Solar Furnaces

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 433 ◽  
Author(s):  
José Carlos Garcia Pereira ◽  
José Rodríguez ◽  
Jorge Cruz Fernandes ◽  
Luís Guerra Rosa
Keyword(s):  
Ray Tracing ◽  
Flux Distribution ◽  
Thermal Power ◽  
Solar Furnace ◽  
High Flux ◽  
Radiation Distribution ◽  
Homogenous Distribution ◽  
Modelling Studies ◽  
Simulation Results ◽  
Ray Tracing Simulation

Comparisons between experimental data and ray-tracing simulation results are presented for the high-flux SF60 solar furnace available at the Plataforma Solar de Almeria, Spain, which has an estimated thermal power of 60 kW. Since an important issue in many applications of solar concentrated radiation is to obtain a radiation distribution that is as homogeneous as possible over the central working area, so-called radiation homogenisers were also used but the degree of success achieved is just satisfactory, as the results show. Finally, further modelling studies using ray-tracing simulations aiming to attain a homogenous distribution of flux by means of double reflexion using two paraboloid surfaces are presented.

Ray-tracing simulation method using piecewise quadratic interpolant for aspheric optical systems

2010 ◽  
Vol 49 (18) ◽  
pp. 3442 ◽  
Author(s):  
Shin-ya Morita ◽  
Yohei Nishidate ◽  
Takashi Nagata ◽  
Yutaka Yamagata ◽  
Cristian Teodosiu
Keyword(s):  
Ray Tracing ◽  
Simulation Method ◽  
Optical Systems ◽  
Ray Tracing Simulation

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

scholarly journals Investigating Intense Rainfall Influence on Distance Measurement with a Time-of-Flight Camera Sensor Using Optical Ray-Tracing Simulation Technique

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1056
Author(s):  
Marcus Baumgart ◽  
Norbert Druml ◽  
Markus Dielacher ◽  
Cristina Consani
Keyword(s):  
Ray Tracing ◽  
Time Of Flight ◽  
Autonomous Driving ◽  
Intense Rainfall ◽  
Signal Suppression ◽  
Tof Camera ◽  
Ray Tracing Simulation ◽  
Camera Sensors ◽  
Optical Ray Tracing ◽  
Rain Effect

Robust, fast and reliable examination of the surroundings is essential for further advancements in autonomous driving and robotics. Time-of-Flight (ToF) camera sensors are a key technology to measure surrounding objects and their distances on a pixel basis in real-time. Environmental effects, like rain in front of the sensor, can influence the distance accuracy of the sensor. Here we use an optical ray-tracing based procedure to examine the rain effect on the ToF image. Simulation results are presented for experimental rain droplet distributions, characteristic of intense rainfall at rates of 25 mm/h and 100 mm/h. The ray-tracing based simulation data and results serve as an input for developing and testing rain signal suppression strategies.

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