Page 605 - Introduction to Information Optics

10.3. Distributed Fiber-Optic Sensors 589

50 200 350 500 650 800 950
M I I | I I I I I I I I l l I I I I I M I I I I I I
i
260-

Nd:YAC br 100
Fluorescense
Lifetime
250— 133
c=- 10

pc

240-^

S=-0.1
Blackbody
radiation
at 1064nm
230- I I I I | I I I I I I I [ I I I I | I I I I 0.01

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Temperature C
Fig, 10.13. Schematic of cross-reference black-body radiation/fluorescent temperature sensor.

10.3. DISTRIBUTED FIBER-OPTIC SENSORS

One of the most important features of fiber-optic sensors is their ability to
implement distributed sensing. Multiple-point measurements can be achieved
by using a single fiber, which provides light weight, compact size, and low cost.
There are basically two types of distributed fiber-optic sensors, intrinsic
distributed sensors and quasi-distributed sensors. In this section, we briefly
introduce the most commonly used distributed fiber-optic sensors.

10.3.1. INTRINSIC DISTRIBUTED FIBER-OPTIC SENSORS
Intrinsic distributed fiber-optic sensors are particular effective for use in
applications where monitoring of a single measurand is required at a large
number of points or continuously over the path of the fiber. These applications