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Spectrally sliced heterodyne coherent receiver with halved electrical bandwidth

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Chinese Optics Letters 2022年第9期20卷 8-13页

作者：吴琪朱逸萧程子钰尹龙杰胡卫生 State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China

A spectrally sliced heterodyne coherent receiver(SHCR)employing four balanced photodetectors and analog-to-digital converters with half of the signal bandwidth is proposed to complete the signal reception and field recovery.We first numerically characterize the performance of SHCR compared with an intradyne coherent receiver and then validate the principle of the SHCR in a proof-of-concept single-polarization experiment.A 60 GBaud 16-quadrature amplitude modulation transmission is experimentally demonstrated over 80 km standard single-mode fiber with a bit-error-rate of 8.5×10^(-4) below the 7%hard-decision forward error correction threshold of 3.8×10^(-3).The SHCR offers a low-cost,hybrid-free,and channel-skew-tolerant candidate for data center interconnects.

关键词： sliced heterodyne coherent receiver heterodyning spectral slicing electrical bandwidth.

Experimental study on minimum resolvable velocity for heterodyne laser Doppler vibrometry

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Chinese Optics Letters 2011年第8期9卷 31-33页

作者：尚建华赵曙光贺岩陈卫标贾宁 School of Information Science and Technology Donghua University Key Laboratory Space Laser Communication and Testing Technology Chinese Academy of Sciences Institute of Acoustics Chinese Academy of Sciences

A high spatial resolution, high velocity resolution all-fiber laser Doppler vibrometry （LDV） based on heterodyne detection for vibration measurements is reported. A linewidth of 1-kHz single-mode continuous fiber laser, polarization-preserving fiber, and a telescope with 30-ram aperture are used in this LDV. With the inphase-quadrature circuit and the digital differentiating discriminator, a high velocity resolution of 96.9 nm/s and a high displacement resolution of 2.5 pm are obtained simultaneously with a glass attached to a piezoceramic transducer. These values correspond to the measurement uncertainties of vibration velocity and displacement within 4.14% and 4.6%, respectively.

关键词： Classifiers Doppler effect Fiber lasers heterodyning Uncertainty analysis Velocity Vibration measurement

Development of an all-fiber heterodyne lidar for range and velocity measurements

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Chinese Optics Letters 2010年第7期8卷 713-716页

作者：杨馥贺岩尚建华陈卫标 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

A 1550-nm all-fiber monostatic lidar system based on linear chirp amplitude modulation and heterodyne detection for the measurements of range and velocity is presented. The signal processing method is given, after which the relationship between the peak frequency values in the final signal spectrum, the target＇s range, and the line-of-sight velocity is obtained in the presence of the fiber end-face-reflected signal plaguing many monostatic lidar systems. The range of an electric fan as well as the line-of-sight fan speed of different levels is tested. This proposed system has a potential application for the space-borne landing system.

关键词： Chirp modulation heterodyning Optical radar Velocity measurement

Polarimetric interferometer for measuring nonlinearity error of heterodyne interferometric displacement system

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Chinese Optics Letters 2013年第6期11卷 25-29页

作者：许素安 Luc Chassagne Suat Topcu 陈乐孙坚严天宏 College of Mechanical and Electrical Engineering China Jiliang University LISV University of Versailles Saint-QuentinVersailles Cedex78035France

This letter presents a polarimetric interferometer （PI） that can measure the ellipsometric parameter θ with an accuracy of 0.01° leading to a potential accuracy of 17 pm. The PI is constructed and compared with a commercial heterodyne interferometer （HI）. Given its low nonlinearity, the PI is used to measure the residual nonlinearity of a heterodyne interferometric displacement system. A rotating half wave plate is used to compensate for a part of the nonlinearity error caused by the misalignment of the axis between input polarizing states and beamsplitter.

关键词： heterodyning Interferometry Polarimeters

Experimental research of circular incoherently synthetic aperture imaging ladar using chirped-laser and heterodyne detection

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Chinese Optics Letters 2012年第9期10卷 30-34页

作者：严毅孙建锋金晓峰周煜职亚楠刘立人 Key Laboratory of Space Laser Communication and Testing Technology Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

Synthetic aperture imaging ladar （SAIL） technique belongs fully coherent processing in both the time domain and space domain and has a rather high implement difficulty. To solve this problem, the concept of circular incoherently SAIL is introduced. A speckle version image of a two-dimensional （2D） letter ＇E＇ target is reconstructed from E-field projection data detected by a circular incoherently SAIL system. The experimental system is constructed by three subsystems using chirped-pulse laser as the light source and heterodyne detection to get the range information of the target. The reconstruction of the image and the noise effect are also discussed in detail.

关键词： Computerized tomography heterodyning Image reconstruction Light sources Synthetic apertures Time domain analysis

Novel high-sensitivity coherent transceiver for optical DPSK/DQPSK signals based on heterodyne detection and electrical delay interferometer

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Chinese Optics Letters 2012年第3期10卷 12-14页

作者：孔德明李岩伍霞王慧郭宏翔洪小斌左勇徐坤李蔚伍剑林金桐 State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

We present a novel coherent transceiver for optical differential phase-shift keying/differential quadrature phase-shift keying （DPSK/DQPSK） signals based on heterodyne detection and electrical delay interferometer. A simulation framework is provided to predict a theoretical sensitivity level for the reported scheme. High sensitivity of –45.18 dBm is achieved for 2.5-Gb/s return-to-zero （RZ）-DPSK signal, and high sensitivities of –36.83 dBm （I tributary） and –35.90 dBm （Q tributary） are observed for 2.5-GBaud/s RZ-DQPSK signal in back-to-back configuration. Transmission for both signals over 100 km is also investigated. Experimental results are discussed and analyzed.

关键词： heterodyning Optical frequency conversion Quadrature phase shift keying Transceivers

Optical heterodyne Herriott-type multipass laser absorption spectrometer

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Chinese Optics Letters 2015年第1期13卷 97-99页

作者：李传亮刘路路邱选兵魏计林邓伦华陈扬骎 Department of Physics School of Applied ScienceTaiyuan University of Science and Technology State Key Laboratory of Precision Spectroscopy East China Normal University

We present a Herriott-type multipass laser absorption spectrometer enhanced by optical heterodyne detection. The proposal is demonstrated by measuring the spectra of water vapor molecule in the region from 12247.6873 to 12249.6954 cm^-1. Compared with direct absorption spectroscopy, the signal-to-noise ratio is improved nearly one magnitude of factor by combining with the optical heterodyne spectroscopy and extra weak absorption lines are observed. The minimum detectable absorption is estimated at 4.36×10^-8 cm^-1 and the measured line shape dominated by Doppler broadening can be precisely recovered by direct transformation of experimental optical heterodyne spectral profile.

关键词： Absorption spectroscopy heterodyning Signal to noise ratio

Laser Doppler vibrometer for real-time speech-signal acquirement

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Chinese Optics Letters 2009年第8期7卷 732-733页

作者：尚建华贺岩刘丹臧华国陈卫标 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

Laser Doppler vibrometer （LDV） has a potential application prospect in remote sensing. Based on the correlation theories of heterodyne detection, a LDV system with a configuration of all fiber and heterodyne techniques is developed to detect the sound signal through the vibration of glass. Experimental results show that the LDV system has an ability to acquire the real-time speech signal 25 m away through glass. While, the system signal-to-noise ratio （SNR） value decreases with the increase of the glass thickness and the detection distance.

关键词： Acoustic intensity Classifiers Correlation theory Doppler effect Glass heterodyning Laser Doppler velocimeters Remote sensing Signal to noise ratio

Developing an Advanced Prototype of the Acousto-Optical Radio-Wave Spectrometer for Studying Star Formation in the Milky Way

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International Journal of Astronomy and Astrophysics 2014年第1期4卷 128-144页

作者： Alexandre S. Shcherbakov Abraham Luna National Institute for Astrophysics Optics & Electronics (INAOE) Puebla Mexico

The designed practically prototype of an advanced acousto-optical radio-wave spectrometer is presented in a view of its application to investigating the Milky Way star formation problems. The potential areas for observations of the cold interstellar medium, wherein such a spectrometer can be exploited successfully at different approximations, are: 1) comparison of the Milky Way case with extragalactic ones at scale of the complete galactic disk;2) global studies of the Galactic spiral arms;and 3) characterization of specific regions like molecular clouds or star clusters. These aspects allow us to suggest that similar instrument will be really useful. The developed prototype of spectrometer is able to realize multi-channel wideband parallel spectrum analysis of very-high-frequency radio-wave signals with an improved resolution power exceeding 103. It includes the 1D-acousto-optic wide-aperture cell as the input device for real-time scale data processing. Here, the current state of developing this acousto-optical spectrometer in frames of the astrophysical instrumentation is briefly discussed, and the data obtained experimentally with a tellurium dioxide crystalline acousto-optical cell are presented. Then, we describe a new technique for more precise spectrum analysis within an algorithm of the collinear wave heterodyning. It implies a two-stage integrated processing, namely, the wave heterodyning of a signal in an acoustically square-law nonlinear medium and then the optical processing in the same solid-state cell. Technical advantage of this approach lies in providing a direct multi-channel parallel processing of ultra-high-frequency radio-wave signals with the resolution power exceeding 104. This algorithm can be realized on a basis of exploiting a large-aperture effective acousto-optical cell, which operates in the Bragg regime and performs the ultra-high-frequency co-directional collinear acoustic wave heterodyning. The general concept and basic conclusions here are confirmed by proof-of-principle experiment

关键词： Star Formation Astronomical Instrumentation Cold Interstellar Medium Acousto-Optical Spectrum Analysis Frequency Bandwidth and Resolution Wide-Aperture Acousto-Optical Cell Collinear Wave heterodyning