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Youzhen Gui

Publications and source records attributed to Youzhen Gui.

5 recordsLinked to original sources

Multi-mode Coherent Detection Ghost Imaging Lidar and Vibration-Mode Imaging

Coherent detection ghost imaging lidar (CD-GI lidar) integrates ghost imaging with coherent detection, thereby achieving enhanced anti-interference and phase-resolved imaging capability. Here, we propose a bucket-detector-based multi-mode coherent detection scheme for CD-GI lidar, where the reflected multi-mode light fields are coherently mixed with a single-mode local oscillator (LO) at the bucket detector photosensitive plane. The bucket-detector-based multi-mode CD-GI lidar system breaks the constraints of Siegman antenna theorem by utilizing field correlation to decouple the reflected multi-mode light fields and reconstructs the spatial distribution of targets' vibration modes. Theoretical analysis of the bucket-detector-based multi-mode CD-GI lidar system is presented in this work, and its feasibility is verified through a series of experiments.

physics.optics

Counting and metrology of distributed atomic clocks using metropolitan fiber

We demonstrate a distributed atomic clocks network between Shanghai Institute of Optics and fine Mechanics (SIOM) and Shanghai Institute of Measurement and Test (SIMT). The frequency signals from three different clocks transfer in one fiber link and four clocks can have comparison in two different labs.By comparing the results of the comparison between the two labs, it was found that the consistency of the frequency signal is on the order of lower than 1E-15. And we also achieve consistency between two locations at the E-15 level of frequency reporting. This scheme can achieve distributed time counting and frequency dissemination of remote atomic clocks, which is a new exploration of the future time keeping laboratory mode.

physics.atom-ph

Fiber-optic joint time and frequency transfer with the same wavelength

Optical fiber links have demonstrated their ability to transfer the ultra-stable clock signals. In this paper we propose and demonstrate a new scheme to transfer both time and radio frequency with the same wavelength based on coherent demodulation technique. Time signal is encoded as a binary phase-shift keying (BPSK) to the optical carrier using electro optic modulator (EOM) by phase modulation and makes sure the frequency signal free from interference with single pulse. The phase changes caused by the fluctuations of the transfer links are actively cancelled at local site by optical delay lines. Radio frequency with 1GHz and time signal with one pulse per second (1PPS) transmitted over a 110km fiber spools are obtained. The experimental results demonstrate that frequency instabilities of 1.7E-14 at 1s and 5.9E-17 at 104s. Moreover, time interval transfer of 1PPS signal reaches sub-ps stability after 1000s. This scheme offers advantages with respect to reduce the channel in fiber network, and can keep time and frequency signal independent of each other.

eess.SP

Time and Frequency Injection into a Stabilized Fiber Link for Multi-clock Dissemination Network

Owing to the characteristics of ultra-low loss and anti-electromagnetic interference, using optical fiber to deliver time and frequency signal has been a preferred choice for high precise clock dissemination and comparison. As a brilliant idea, one has been able to reproduce ultra-stable signals from one local station to multiple users. In this paper, we take a step further. A concept of multi-clock (in different locations) dissemination for multi-terminals is presented. By injecting frequency signals into one stabilized ring-like fiber network, the relative stabilities of 3.4e-14@1s for a master clock dissemination and 5.1e-14@1s for a slave clock dissemination have been achieved. The proposed scheme can greatly simplify the future 'N' to 'N' time and frequency dissemination network, especially facing a multi-clock comparison situation.

physics.optics

Joint time and frequency dissemination network over delay-stabilized fiber optic links

A precise fiber-based time and frequency dissemination scheme for multiple users with a tree-like branching topology is proposed. Through this scheme, ultra-stable signals can be easily accessed online anywhere along the fiber without affecting other sites. The scheme is tested through an experiment, in which a modulated frequency signal and a synchronized time signal are transferred to multiple remote sites over a delay-stabilized fiber optic links that are over 50 km long. Results show that the relative stabilities are 5E-14@1s and 2E-17@10000s. Meanwhile, compared with each site, time synchronization precision is less than 80 ps. These results can pave the way to practical applications in joint time and frequency dissemination network systems.

physics.optics