Optical sensing occurs when a change of an external magnitude modifies the optical properties of the sensing area along the guiding element and modulates the light characteristics (intensity, phase, polarization...).

Great effort are done in the developing of sensing devices for monitoring different physical and chemical parameters. Being the first ones who have reached the industrialization phase.

However, opto(bio)chemical sensors may have the higher growth, due to their application in different fields as: industrial process automatization, environmental control and clinical monitoring.

As examples of integrated optical sensor, two kind of opto-chemical sensors have been developed t:

• Intensity modulation, through the absorption of the propagated mode through the waveguide.
• Phase modulation, sensible to the variation of the real part of the refractive index under measure.

Moreover, combining optical components and mechanical actuators an Optical Waveguide Cantilever able to measure biochemical interactions have been designed and fabricated.

Opto(bio)chemical sensors based on integrated optical components

Examples of Absorption, Mach-Zehnder Interferometer and Optical actuated Cantilever as transducers for Opto(bio)chemical sensors.

• K+ sensor with a dynamic range of 3.0 absorption units.
• TIR-MZI with a limit of detection of 2.5•10-6 Units of Refractive Index
• Optical Waveguide Cantilever displacement precision of 0,04 nm, and resolution of 18 fmHz-1/2

Light coupling to an array
of Optical Waveguide Cantilevers