A low cost interrogation scheme is demonstrated for a refractometer based on an in-line fiber long period grating (LPG) Mach–Zehnder interferometer. Using this interrogation scheme the minimum detectable change in refractive index of ?n ~ 1.8×10-6 is obtained, which is the highest resolution achieved using a fiber LPG device, and is comparable to precision techniques used in the industry including high performance liquid chromatography and ultraviolet spectroscopy.
Bibliographical noteCopyright (2002) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Allsop, Thomas D.P.; Reeves, R.; Webb, David J.; Bennion, Ian and Neal, R. (2002). A high sensitivity refractometer based upon a long period grating Mach-Zehnder interferometer. Review of Scientific Instruments, 73 (4), pp. 1702-1705 and may be found at http://rsi.aip.org/resource/1/rsinak/v73/i4/p1702_s1.
- interrogation scheme
- an in-line fiber long period grating
- Mach–Zehnder interferometer
- high performance liquid chromatography
- ultraviolet spectroscopy