Patent ID: 7050176

Claim:
A sensor assembly for measuring one or more factors contributing to a change in the effective refractive index of a sensor component thereof caused by the introduction of or changes in a stimulus in a localised environment, wherein said sensor component includes either: (1) one or more sensing layers capable of inducing a measurable response to a change in the localised environment caused by the introduction of or changes in the stimulus; or (2) a sensing waveguide capable of exhibiting a measurable response to a change in the localised environment caused by the introduction of or changes in the stimulus, said sensor assembly further comprising: first irradiating means for irradiating the sensor component with electromagnetic radiation in TM mode; second irradiating means for irradiating the sensor component with electromagnetic radiation in TE mode; a measuring means for measuring the measurable response; and a synchronising means for synchronising the measuring means with the first and second irradiating means so as to correlate the measurement of the measurable response with the irradiation of the sensor component with electromagnetic radiation in TE and TM modes.