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Ultrafast-optical-pump -- structural-probe measurements, including ultrafast electron and x-ray scattering, provide direct experimental access to the fundamental timescales of atomic motion, and are thus foundational techniques for studying…

The main challenge in 3D object detection from LiDAR point clouds is achieving real-time performance without affecting the reliability of the network. In other words, the detecting network must be confident enough about its predictions. In…

Computer Vision and Pattern Recognition · Computer Science 2023-01-11 Youshaa Murhij , Alexander Golodkov , Dmitry Yudin

Integrating two-dimensional (2D) crystals into optical fibers can grant them optoelectronic properties and extend their range of applications. However, our ability to produce complicated structures is limited by the challenges of chemical…

Applied Physics · Physics 2018-07-03 Yi-feng Xiong , Jin-hui Chen , Fei Xu

LiDAR and camera are two important sensors for 3D object detection in autonomous driving. Despite the increasing popularity of sensor fusion in this field, the robustness against inferior image conditions, e.g., bad illumination and sensor…

Computer Vision and Pattern Recognition · Computer Science 2022-03-23 Xuyang Bai , Zeyu Hu , Xinge Zhu , Qingqiu Huang , Yilun Chen , Hongbo Fu , Chiew-Lan Tai

LiDARs are usually more accurate than cameras in distance measuring. Hence, there is strong interest to apply LiDARs in autonomous driving. Different existing approaches process the rich 3D point clouds for object detection, tracking and…

Robotics · Computer Science 2020-10-15 You Li , Clément Le Bihan , Txomin Pourtau , Thomas Ristorcelli

In this paper, we report on the development progress of correlation-based optical time domain reflectometry (OTDR). Substituting the direct detection receiver with a coherent receiver enables to extract the phase and polarization…

Instrumentation and Detectors · Physics 2022-09-30 Florian Azendorf , André Sandmann , Michael Eiselt , Bernhard Schmauss

Optimising wind turbine performance involves maximising energy harvesting while seeking to minimise load fatigues on the tower structure, blades and rotor. To improve turbine control performance, wind preview measurement technologies such…

Systems and Control · Electrical Eng. & Systems 2019-10-18 Amin Mahdizadeh , Robert Schmid , Denny Oetomo

Fiber-delay measurement is one of the key fundamental technologies in numerous fields. Here we propose and experimentally demonstrate a high-precision and concise optical time delay measurement system based on the technique of linear…

Optics · Physics 2023-12-19 Yufei Zhang , Ziyang Chen , Dongrui Yu , Jialin Niu , Xing Chen , Hong Guo

This paper presents an innovative method for automatically detecting dust accumulation on a PV system and notifying the user to clean it instantly. The accumulation of dust, bird, or insect droppings on the surface of photovoltaic (PV)…

Obstacle detection is one of the basic tasks of a robot movement in an unknown environment. The use of a LiDAR (Light Detection And Ranging) sensor allows one to obtain a point cloud in the vicinity of the sensor. After processing this…

Robotics · Computer Science 2024-04-12 Lukas Kratochvila

The recent introduction of coherent optical communications has created a compelling need for ultra-fast phase-sensitive measurement techniques operating at milliwatt peak power levels and in time scales ranging from sub-picoseconds to…

- Both Lidars and Radars are sensors for obstacle detection. While Lidars are very accurate on obstacles positions and less accurate on their velocities, Radars are more precise on obstacles velocities and less precise on their positions.…

Robotics · Computer Science 2019-07-02 Hatem Hajri , Mohamed-Cherif Rahal

The coherent reflectivity of a dense, relativistic, ultra-thin electron layer is derived analytically for an obliquely incident probe beam. Results are obtained by two-fold Lorentz transformation. For the analytical treatment, a plane…

Plasma Physics · Physics 2009-11-13 Hui-Chun Wu , Jürgen Meyer-ter-Vehn

The coupling of Rydberg vapour medium to both microwave and optical fields allows harnessing the merits of all-optical detection, e.g. weak disruption of the measured field and invulnerability to extremely strong fields, owing to the lack…

Atomic Physics · Physics 2025-10-20 Sebastian Borówka , Mateusz Mazelanik , Wojciech Wasilewski , Michał Parniak

Integrated photodetectors are essential components of scalable photonics platforms for quantum and classical applications. However, most efforts in the development of such devices to date have been focused on infrared telecommunications…

Applied Physics · Physics 2021-04-14 Salih Yanikgonul , Victor Leong , Jun Rong Ong , Ting Hu , Ching Eng Png , Leonid Krivitsky

A phase retrieval technique using a spatial light modulator (SLM) and a phase diffuser for a fast reconstruction of smooth wave fronts is demonstrated experimentally. Diffuse illumination of a smooth test object with the aid of a phase…

Optics · Physics 2015-06-11 Mostafa Agour , Percival F. Almoro , Claas Falldorf

Reliable detection of humans beneath forest canopy remains a difficult remote-sensing challenge due to sparse, structured, and viewpoint-dependent occlusion. This paper presents a multimodal proof-of-concept pipeline that integrates three…

Computer Vision and Pattern Recognition · Computer Science 2026-05-18 Nitik Jain , Mangal Kothari

In distributed fiber-optic sensing based on optical frequency domain reflectometry (OFDR), Doppler frequency shifts due to the changes of disturbances during one sweep period introduce demodulation errors that accumulate along both the…

Optics · Physics 2024-10-28 Qiang Yang , Weilin Xie , Congfan Wang , Bowen Li , Xin Li , Xiang Zheng , Wei Wei , Yi Dong

The increasing deployment of small drones as tools of conflict and disruption has amplified their threat, highlighting the urgent need for effective anti-drone measures. However, the compact size of most drones presents a significant…

Computer Vision and Pattern Recognition · Computer Science 2024-12-24 Hanfang Liang , Jinming Hu , Xiaohuan Ling , Bing Wang

Lidar-based object detectors are critical parts of the 3D perception pipeline in autonomous navigation systems such as self-driving cars. However, they are known to be sensitive to adverse weather conditions such as rain, snow and fog due…

Computer Vision and Pattern Recognition · Computer Science 2021-07-16 Velat Kilic , Deepti Hegde , Vishwanath Sindagi , A. Brinton Cooper , Mark A. Foster , Vishal M. Patel