Free-Space Heterochronous Imaging Reception of Multiple Optical Signals

Mao, Wei; Kahn, Joseph M.

doi:10.1109/tcomm.2003.822755

Cited by 26 publications

(13 citation statements)

References 10 publications

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“…4(d) deviate from those of Fig. 3(d) with a standard deviation below 10 . The observed deviations are greatest for orientations with large, i.e., glancing, angles of incidence off of one or more PDs, though such deviations at the angular extremes are well within the required accuracy for the retrodetector alignment process (as the overall surface concavity of the differential distribution is used to minimize the photocurrent differential sum and optimize the structure's alignment).…”

Section: Resultsmentioning

confidence: 62%

“…Incident light detection is typically accomplished with a photodetector, while retroreflection is provided by a separate corner-cube retroreflector. Modulation of the returning signal, allowing communication in the bidirectional link, is typically accomplished by mechanical beam deflectors on the incorporated corner-cube mirrors [10] or liquid crystal shutters [11]. Given the motivations for emerging multidirectional (e.g., Smart Dust) technologies, we present an architecture that merges the detection and retroreflection capabilities of active remote sensing.…”

Section: Introductionmentioning

confidence: 99%

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Differential Retro-Detection for Remote Sensing Applications

Jin

Holzman

2010

IEEE Sensors J.

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A retro-detection technique is introduced for simultaneous optical retroreflection, detection, and control in bidirectional sensor links. An architecture with three orthogonal photodiodes (PDs) is used to retroreflect incident light and sample the incident optical signals. Such a system establishes a two-way (bidirectional) optical link. Moreover, the three photocurrent signals can be used in differential combinations for active control and optimization of the alignment. The theory and methodology for the optical retroreflection, detection, and control characteristics are presented, and the technique is verified experimentally with a silicon PD retro-detection prototype. The active remote sensing capabilities of the retrodetector are found to be successful.

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Section: Resultsmentioning

confidence: 62%

Section: Introductionmentioning

confidence: 99%

Differential Retro-Detection for Remote Sensing Applications

Jin

Holzman

2010

IEEE Sensors J.

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“…Interested readers may refer to existent literature on this topic (e.g. [29]- [31]). Let us assume synchrony between the OWAS devices and the camera in what follows.…”

Section: The Imaging Sensor-based Optical Receivermentioning

confidence: 99%

A High-Speed Camera-Based Approach to Massive Sound Sensing With Optical Wireless Acoustic Sensors

Nava

Nguyen

Kamamoto

et al. 2015

IEEE Trans. Comput. Imaging

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This paper introduces an optical wireless audio system, which takes advantage of the parallel transmission feature offered by the arrangement of LEDs and a high-speed video camera. The motivation for building such system is the limitation encountered when deploying huge arrays of sound sensors, as existent wired and RF wireless microphones are undermined by complexity, energy, and bandwidth issues. In contrast, the proposed prototype is able to simultaneously capture 120 audio channels with full bandwidth each. Although the scalability to more channels is currently constrained by the camera interface hardware, our numerical analysis suggests that the proposed algorithms can decode optical signals of over 12 500 audio channels in a single GPU card. We discuss the various challenges involved in its deployment from the optical, image, and audio signal processing standpoints, and develop theoretical and practical solutions to accomplish a full real-time system integration. We further present examples of typical applications such as acoustic imaging of sound fields by beamforming with microphone arrays.Index Terms-High speed camera, free space optical communication, wireless sensor networks, microphone arrays, beamforming, acoustic imaging, parallel processing. Manuscript

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“…Distinct bias frequencies are applied to support diversity reception [10,15]. Modulated-retroreflection techniques are shown elsewhere [12][13][14]. The level of detection and retroreflection depends upon the incident signal's angle of arrival, which is defined according to the azimuthal angle ϕ in the xy plane and the polar angle θ off the z axis.…”

Section: Design and Operation Of The Devicementioning

confidence: 99%

“…Multidirectional reception allows for an increased number of established communication channels for angular [10] or imaging [11] diversity reception, and this leads to improved link performance. At the same time, bidirectional transmission/reception can facilitate passive uplink communications [12][13][14] by using OWC receivers that detect, retroreflect, and modulate incident optical beams. This minimizes the alignment sensitivity and eliminates the need for broadcasting at the receivers.…”

Section: Introductionmentioning

confidence: 99%

Ultrafast transient responses of optical wireless communication detectors

et al. 2013

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In this work, fundamental ultrafast transient responses are studied for optical wireless communication (OWC) detectors. It is shown that material impulse responses, associated with transient photoconductivity, and geometrical input responses, associated with transient optical power, must be considered in tandem when OWC photodetection is pursued with broad spectral and directional characteristics. An OWC detector, composed of GaAs photoconductive gaps in a corner-cube geometry, is fabricated and analyzed. The GaAs material response times are investigated experimentally and found to range from approximately 3 ps to 200 fs for 390 nm (violet) to 780 nm (red) photoexcitation. The geometrical response times are investigated theoretically and found to range from approximately 2 to 20 ps for device dimensions from 1 to 10 mm. The overall response times manifest themselves in two distinct dimensional regimes, with differing levels of wavelength and dimension dependence. The relevance of these findings is discussed for future ultrafast OWC detectors.

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Free-Space Heterochronous Imaging Reception of Multiple Optical Signals

Cited by 26 publications

References 10 publications

Differential Retro-Detection for Remote Sensing Applications

Differential Retro-Detection for Remote Sensing Applications

A High-Speed Camera-Based Approach to Massive Sound Sensing With Optical Wireless Acoustic Sensors

Ultrafast transient responses of optical wireless communication detectors

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