Specialty Optical Fibers Handbook

complex and costly White cell to provide an effective means for gas analysis.

Unlike evanescent wave spectroscopy in which light is coupled out of a solid-

core–only fiber into media in contact with the core, all of the light is passing

through the gas in the hollow guide cell, making this a sensitive, quick response

fiber sensor. Temperature measurements may be aided by using an HGW to

transmit blackbody radiation from a remote site to an IR detector. Such an

arrangement has been used to measure jet engine temperatures.

13.7 SUMMARY

During the past 30 years of the development of IR fibers, there has been a

great deal of fundamental research designed to produce a fiber with optical and

mechanical properties close to that of silica. IR fibers are still ...