Centimeter-Wave Free-Space Time-of-Flight Imaging

• URL: http://arxiv.org/abs/2105.11606v1
• Date: Tue, 25 May 2021 01:57:10 GMT
• Title: Centimeter-Wave Free-Space Time-of-Flight Imaging
• Authors: Seung-Hwan Baek, Noah Walsh, Ilya Chugunov, Zheng Shi, Felix Heide
• Abstract summary: We propose a computational imaging method for all-optical free-space correlation before photo-conversion that achieves micron-scale depth resolution. We propose an imaging approach with resonant polarization modulators and devise a novel optical dual-pass frequency-doubling which achieves high modulation contrast at more than 10GHz. We validate the proposed method in simulation and experimentally, where it achieves micron-scale depth precision.
• Score: 25.15384123485028
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Depth cameras are emerging as a cornerstone modality with diverse applications that directly or indirectly rely on measured depth, including personal devices, robotics, and self-driving vehicles. Although time-of-flight (ToF) methods have fueled these applications, the precision and robustness of ToF methods is limited by relying on photon time-tagging or modulation after photo-conversion. Successful optical modulation approaches have been restricted fiber-coupled modulation with large coupling losses or interferometric modulation with sub-cm range, and the precision gap between interferometric methods and ToF methods is more than three orders of magnitudes. In this work, we close this gap and propose a computational imaging method for all-optical free-space correlation before photo-conversion that achieves micron-scale depth resolution with robustness to surface reflectance and ambient light with conventional silicon intensity sensors. To this end, we solve two technical challenges: modulating at GHz rates and computational phase unwrapping. We propose an imaging approach with resonant polarization modulators and devise a novel optical dual-pass frequency-doubling which achieves high modulation contrast at more than 10GHz. At the same time, centimeter-wave modulation together with a small modulation bandwidth render existing phase unwrapping methods ineffective. We tackle this problem with a neural phase unwrapping method that exploits that adjacent wraps are often highly correlated. We validate the proposed method in simulation and experimentally, where it achieves micron-scale depth precision. We demonstrate precise depth sensing independently of surface texture and ambient light and compare against existing analog demodulation methods, which we outperform across all tested scenarios.

Related papers

• Super-resolution imaging based on active optical intensity interferometry [14.452089688779049]
  In contrast to amplitude (phase) interferometry, intensity interferometry exploits the quantum nature of light to measure the photon bunching effect in thermal light. In outdoor environments, we image two-dimension millimeter-level targets over 1.36 kilometers at a resolution of 14 times the diffraction limit of a single telescope.
  arXiv  Detail & Related papers  (2024-04-24T06:51:01Z)
• Optimal baseline exploitation in vertical dark-matter detectors based on atom interferometry [50.06952271801328]
  Several terrestrial detectors for gravitational waves and dark matter based on long-baseline atom interferometry are currently in the final planning stages or already under construction. We show that resonant-mode detectors based on multi-diamond fountain gradiometers achieve the optimal, shot-noise limited, sensitivity if their height constitutes 20% of the available baseline.
  arXiv  Detail & Related papers  (2023-09-08T08:38:24Z)
• Detecting changes to sub-diffraction objects with quantum-optimal speed and accuracy [0.8409980020848168]
  We evaluate the best possible average latency, for a fixed false alarm rate, for sub-diffraction incoherent imaging. We find that direct focal-plane detection of the incident optical intensity achieves sub-optimal detection latencies. We verify these results via Monte Carlo simulation of the change detection procedure and quantify a growing gap between the conventional and quantum-optimal receivers.
  arXiv  Detail & Related papers  (2023-08-14T16:48:18Z)
• Phase sensitivity of spatially broadband high-gain SU(1,1) interferometers [0.0]
  We present a theoretical description of spatially multimode SU (1,1) interferometers operating at low and high parametric gains. Our approach is based on a step-by-step solution of a system of integro-differential equations for each nonlinear interaction region. We investigate plane-wave and Gaussian pumping and show that for any parametric gain, there exists a region of phases for which the phase sensitivity surpasses the standard shot-noise scaling.
  arXiv  Detail & Related papers  (2023-07-04T13:51:31Z)
• Swept-Angle Synthetic Wavelength Interferometry [22.706332189135242]
  We present a new imaging technique, swept-angle synthetic wavelength interferometry, for full-field micron-scale 3D sensing. Our technique uses light consisting of two narrowly-separated optical wavelengths, resulting in per-pixel interferometric measurements. We build an experimental prototype, and use it to demonstrate these capabilities by scanning a variety of objects.
  arXiv  Detail & Related papers  (2022-05-21T18:38:05Z)
• Two-colour spectrally multimode integrated SU(1,1) interferometer [77.34726150561087]
  We develop and investigate an integrated multimode two-colour SU (1,1) interferometer that operates in a supersensitive mode. By ensuring a proper design of the integrated platform, we suppress dispersion and thereby significantly increase the visibility of the interference pattern. We demonstrate that such an interferometer overcomes the classical phase sensitivity limit for wide parametric gain ranges, when up to $3*104$ photons are generated.
  arXiv  Detail & Related papers  (2022-02-10T13:30:42Z)
• Passive Inter-Photon Imaging [18.739224941453983]
  Digital camera pixels measure image intensities by converting incident light energy into an analog electrical current, and then digitizing it into a fixed-width binary representation. This direct measurement method suffers from limited dynamic range and poor performance under extreme illumination. We propose a novel intensity cue based on measuring inter-photon timing, defined as the time delay between detection of successive photons.
  arXiv  Detail & Related papers  (2021-03-31T18:44:52Z)
• Leveraging Spatial and Photometric Context for Calibrated Non-Lambertian Photometric Stereo [61.6260594326246]
  We introduce an efficient fully-convolutional architecture that can leverage both spatial and photometric context simultaneously. Using separable 4D convolutions and 2D heat-maps reduces the size and makes more efficient.
  arXiv  Detail & Related papers  (2021-03-22T18:06:58Z)
• Spectrally multimode integrated SU(1,1) interferometer [50.591267188664666]
  The presented interferometer includes a polarization converter between two photon sources and utilizes a continuous-wave (CW) pump. We show that this configuration results in almost perfect destructive interference at the output and supersensitivity regions below the classical limit.
  arXiv  Detail & Related papers  (2020-12-07T14:42:54Z)
• Fast Generation and Detection of Spatial Modes of Light using an Acousto-Optic Modulator [62.997667081978825]
  spatial modes of light provide a high-dimensional space that can be used to encode both classical and quantum information. Current approaches for dynamically generating and measuring these modes are slow, due to the need to reconfigure a high-resolution phase mask. We experimentally realize this approach, using a double-pass AOM to generate one of five orbital angular momentum states. We are able to reconstruct arbitrary states in under 1 ms with an average fidelity of 96.9%.
  arXiv  Detail & Related papers  (2020-07-31T14:58:30Z)
• Correlation Plenoptic Imaging between Arbitrary Planes [52.77024349608834]
  We show that the protocol enables to change the focused planes, in post-processing, and to achieve an unprecedented combination of image resolution and depth of field. Results lead the way towards the development of compact designs for correlation plenoptic imaging devices based on chaotic light, as well as high-SNR plenoptic imaging devices based on entangled photon illumination.
  arXiv  Detail & Related papers  (2020-07-23T14:26:14Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.