Long-distance fiber-optic point-sensing systems based on random fiber lasers

We report the development of a new type of space lidar specifically designed for missions to small planetary bodies for both topographic mapping and support of sample collection or landing. The instrument is designed to have a wide dynamic range with several operation modes for different mission phases. The laser transmitter consists of a fiber laser that is intensity modulated with a return-to-zero pseudo-noise (RZPN) code. The receiver detects the coded pulse-train by correlating the detected signal with the RZPN kernel. Unlike regular pseudo noise (PN) lidars, the RZPN kernel is set to zero outside laser firing windows, which removes most of the background noise over the receiver integration time. This technique enables the use of low peak-power but high pulse-rate lasers, such as fiber lasers, for long-distance ranging without aliasing. The laser power and the internal gain of the detector can both be adjusted to give a wide measurement dynamic range. The laser modulation code pattern can also be reconfigured in orbit to optimize measurements to different measurement environments. The receiver uses a multi-pixel linear mode photon-counting HgCdTe avalanche photodiode (APD) array with near quantum limited sensitivity at near to mid infrared wavelengths where many fiber lasers and diode lasers operate. The instrument is modular and versatile and can be built mostly with components developed by the optical communication industry.

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Long-distance fiber optic white-light sensing system with synthetic sources

10.1117/12.255341 ◽

1996 ◽

Author(s):

Yun-Jiang Rao ◽

David A. Jackson

Keyword(s):

White Light ◽

Fiber Optic ◽

Long Distance ◽

Light Sensing ◽

Sensing System

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Referencing In Fiber Optic Sensing Systems

10.1117/12.940678 ◽

1987 ◽

Cited By ~ 1

Author(s):

Grigory Adamovsky

Keyword(s):

Fiber Optic ◽

Sensing Systems ◽

Fiber Optic Sensing

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Recent Progress of Fiber-Optic Sensors for the Structural Health Monitoring of Civil Infrastructure

Sensors ◽

10.3390/s20164517 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4517

Author(s):

Tiange Wu ◽

Guowei Liu ◽

Shenggui Fu ◽

Fei Xing

Keyword(s):

Structural Health Monitoring ◽

Health Monitoring ◽

Electromagnetic Interference ◽

Fiber Optic ◽

Materials Science ◽

Fiber Optic Sensors ◽

Civil Infrastructure ◽

Basic Principles ◽

Structural Health ◽

Sensing Systems

In recent years, with the development of materials science and architectural art, ensuring the safety of modern buildings is the top priority while they are developing toward higher, lighter, and more unique trends. Structural health monitoring (SHM) is currently an extremely effective and vital safeguard measure. Because of the fiber-optic sensor’s (FOS) inherent distinctive advantages (such as small size, lightweight, immunity to electromagnetic interference (EMI) and corrosion, and embedding capability), a significant number of innovative sensing systems have been exploited in the civil engineering for SHM used in projects (including buildings, bridges, tunnels, etc.). The purpose of this review article is devoted to presenting a summary of the basic principles of various fiber-optic sensors, classification and principles of FOS, typical and functional fiber-optic sensors (FOSs), and the practical application status of the FOS technology in SHM of civil infrastructure.

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