Quantum mechanics

Reflection (computer programming)

Engineering

Psychoanalysis

Bragg's law

Materials science

Refractive index

Planar

Computer graphics (images)

Computer science

In situ

Wavelength

Transverse plane

Physics

Psychology

Waveguide

Temperature measurement

Optics

Grating

Structural engineering

Programming language

Meteorology

Birefringence

Diffraction

Compensation (psychology)

Optoelectronics

Fiber Bragg grating

Sensors and Actuators B Chemical

An exposed Bragg grating incorporated into a planar waveguide forms an optical device that acts as a refractive index sensor. The exposed evanescent field causes the Bragg peak to be sensitive to the refractive index of its surroundings and can be used to detect changes in this environment. The method reported is able to provide accurate temperature compensation by applying a scaling factor derived from measurement of the birefringence of the transverse electric (TE) and transverse magnetic (TM) modes of the Bragg reflection. For a fluid sensor, fluctuations in ambient temperature can be both accounted for and compensated to produce a temperature-insensitive sensor.

A temperature-insensitive Bragg grating sensor—Using orthogonal polarisation modes for in situ temperature compensation