Biomedical Measurements

The General Principle of Fiber Optic-based Sensor

Optical sensors are typically interfaced with an optical unit. This optical component supplies the excitation light, which may be from a monochromatic source such as a diode laser or from a broadband source e.g. quartz-halogen that is filtered to provide a narrow bandwidth of excitation.

Fiber Optic-based sensor
Fig: Fiber-optic based sensor

Typically, two wavelengths of light are employed: one that is sensitive to changes in the species to be measured and one that is unaffected by changes in the analyte concentration. This wavelength serves as a reference and is used to compensate for fluctuations in the source output and detector stability. The light output from the optic module is coupled into a fiber optic cable through the appropriate lenses and an optical connector.

Related: Optical Fiber Sensors and their Applications in Medical Field

In fluorescence-based sensors, the incident light excites fluorescence emission, which changes in intensity as a function of the concentration of the analyte to be measured. The emitted light travels back down the fiber to the monitor where the light is measured by a photodetector.

John Mulindi

John Mulindi has a background in Instrumentation, and he writes on various topics ranging from Technical, Business to Internet marketing fields. He likes reading, watching football, writing and taking on adventure walks in free time.

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