Analysis of prospects of fiber optic long-distance telephone network architecture

1991 ◽  
Vol 29 (7) ◽  
pp. 23-25
Author(s):  
L.E. Varakin ◽  
A.S. Adjemov ◽  
L.I. Golyayeva ◽  
A.F. Petrov ◽  
V.M. Tjomkin
Keyword(s):  
Network Architecture ◽  
Fiber Optic ◽  
Telephone Network ◽  
Long Distance

Hybrid FSO/fiber optic link based reliable & energy efficient WDM optical network architecture

2021 ◽  
Vol 61 ◽  
pp. 102422
Author(s):  
Amit Kumar Garg ◽  
Vijay Janyani ◽  
Bostjan Batagelj ◽  
N.H. Zainol Abidin ◽  
M.H. Abu Bakar
Keyword(s):  
Energy Efficient ◽  
Network Architecture ◽  
Fiber Optic ◽  
Optical Network

Distributed Fiber Optic Strain Sensing with Embedded Small-Diameter Optical Fibers in CFRP Laminate

2007 ◽  
Vol 334-335 ◽  
pp. 1013-1016
Author(s):  
Tadahito Mizutani ◽  
Takafumi Nishi ◽  
Nobuo Takeda
Keyword(s):  
Spatial Resolution ◽  
Optical Fibers ◽  
Composite Structures ◽  
Fiber Optic ◽  
Current Trend ◽  
Small Diameter ◽  
Long Distance ◽  
Distributed Sensors ◽  
Cfrp Laminate ◽  
Sensing Applications

Although demand for composite structures rapidly increase due to the advantages in weight, there are few effective assessment techniques to enable the quality control and guarantee the durability. In particular, an invisible microscopic damage detection technology is highly required because damages such as transverse cracks, debondings, or delaminations can lead to the critical failure of the structures. Among many non-destructive evaluation (NDE) methods for composite structures, fiber optic sensors are especially attractive due to the high sensitivity, the lightweight, and the small size. In the current trend of the structural health monitoring technology, fiber Bragg gratings (FBG) sensors are frequently used as strain or temperature sensors, and Brillouin scattering sensors are also often used for a long distance distributed measurement. The Brillouin distributed sensors can measure strain over a distance of 10km while a spatial resolution was limited to 1m. Some novel sensing method is proposed to improve the spatial resolution. The pulse-prepump Brillouin optical time domain analysis (PPP-BOTDA) is one of the latest distributed sensing applications with a cm-order high spatial resolution. The PPP-BOTDA commercial product has the spatial resolution of 10cm, and can measure the strain with a precision of ±25og. This precision, however, can be achieved by using conventional single-mode optical fibers. In our research, small-diameter optical fibers with a cladding diameter of 40om were embedded in the CFRP laminate to avoid the deterioration of the CFRP mechanical properties. Thus, in order to verify the performance of PPP-BOTDA, the distributed strain measurement was conducted with the small-diameter optical fibers embedded in the CFRP laminate.

scholarly journals Long distance telemetry of fetal heart rate from patients' homes using public telephone network.

BMJ ◽  
1983 ◽  
Vol 286 (6377) ◽  
pp. 1545-1545 ◽  
Author(s):  
K J Dalton ◽  
A J Dawson ◽  
N A Gough
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Telephone Network ◽  
Long Distance ◽  
Public Telephone

Ultra long distance distributed fiber-optic system for intrusion detection

2012 ◽  
Author(s):  
Dongsheng Tu ◽  
Shangran Xie ◽  
Zhaogong Jiang ◽  
Min Zhang
Keyword(s):  
Intrusion Detection ◽  
Fiber Optic ◽  
Optic System ◽  
Long Distance ◽  
Fiber Optic System
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