scholarly journals Single-shot cross-correlator for pulse-contrast characterization of high peak-power lasers

Author(s):  
Jingui Ma ◽  
Peng Yuan ◽  
Jing Wang ◽  
Guoqiang Xie ◽  
Heyuan Zhu ◽  
...  

Pulse contrast is a crucial parameter of high peak-power lasers since the prepulse noise may disturb laser–plasma interactions. Contrast measurement is thus a prerequisite to tackle the contrast challenge in high peak-power lasers. This paper presents the progress review of single-shot cross-correlator (SSCC) for real-time contrast characterization. We begin with the key technologies that enable an SSCC to simultaneously possess high dynamic range ($10^{10}$), large temporal window (50–70 ps) and high fidelity. We also summarize the instrumentation of SSCC prototypes and their applications on five sets of petawatt laser facilities in China. Finally, we discuss how to extend contrast measurements from time domain to spatiotemporal domain. Real-time and high-dynamic-range contrast measurements, provided by SSCC, can not only characterize various complex noises in high peak-power lasers but also guide the system optimization.

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Yongzhi Wang ◽  
Jingui Ma ◽  
Jing Wang ◽  
Peng Yuan ◽  
Guoqiang Xie ◽  
...  

2018 ◽  
Vol 11 (4) ◽  
pp. 2041-2049 ◽  
Author(s):  
Soumyabrata Dev ◽  
Florian M. Savoy ◽  
Yee Hui Lee ◽  
Stefan Winkler

Abstract. Sky–cloud images obtained from ground-based sky cameras are usually captured using a fisheye lens with a wide field of view. However, the sky exhibits a large dynamic range in terms of luminance, more than a conventional camera can capture. It is thus difficult to capture the details of an entire scene with a regular camera in a single shot. In most cases, the circumsolar region is overexposed, and the regions near the horizon are underexposed. This renders cloud segmentation for such images difficult. In this paper, we propose HDRCloudSeg – an effective method for cloud segmentation using high-dynamic-range (HDR) imaging based on multi-exposure fusion. We describe the HDR image generation process and release a new database to the community for benchmarking. Our proposed approach is the first using HDR radiance maps for cloud segmentation and achieves very good results.


2014 ◽  
Vol 12 (4) ◽  
pp. 747-762 ◽  
Author(s):  
Pierre-Jean Lapray ◽  
Barthélémy Heyrman ◽  
Dominique Ginhac

Sign in / Sign up

Export Citation Format

Share Document