Integrated optical and optofluidic sensors

SensOptoThe optofluidic sensors are a recent innovation in sensoristics. They combine the unique characteristics of liquids to those of microfluidics leading to innovative devices. In this field, for instance, there are sensors based on liquid jet waveguides, recently developed by IREA researchers. Moreover, optofluidic sensors provide easy integration to electronic devices.

Integrated optical sensors, which integrate on the same platform optoelectronic elements for the signal processing, offer great advantages in terms of costs, weight and size. These devices, in fact, can be fabricated with reduced costs as respect to the conventional counterparts. Moreover, due to reduced dimensions, they require a very small amount of sample thus reducing sample consuming and allowing field deployability.

The research activity of IREA in the field of integrated micro-sized devices is focused on the realization of optofluidic devices, which makes use of fluid to tune the optical property of the device itself. Optofluidic devices allow the full integration of the microfluidic and optic elements, leading to very compact devices. Moreover, since the light propagates in the same channel wherein the fluid flows, stronger interaction efficiency between the sample to be tested and the light can be obtained, thus improving the sensitivity. The devices have been fabricated both with silicon or polymer (typically PDMS, PMMA) and by developing hybrid approaches that make use of both silicon and polymer. Polymer-based devices have been fabricated by using soft lithography technique and/or by milling machine.

In this framework, IREA researchers have a long experience in the design, modelling, fabrication and characterization of a new class of optofluidic waveguides called Antiresonant Reflecting Optical Waveguides (ARROW), which are capable to confine light to core with a refractive index lower than either of the surrounding cladding layers. By developing an innovative hybrid approach, the scientists of IREA have recently demonstrated a hybrid optofluidic waveguide, named h-ARROW, which has been obtained by substituting the top antiresonant cladding layers with a PDMS layer.

These new waveguides have been fabricated and characterized and successfully applied for the realization of an integrated optofluidic platform for sensing application. The ARROW waveguides, on the basis of the design principle, can be directly used as refractive index sensor or they can be exploited as flow cell in order to increase the light interaction with the sample to be tested (liquids or gases).

These waveguides have also been applied as a basic element in the realization of more complex photonic devices like:
- Refractometers
- Optofluidic multimode interference coupler
- Tunable optofluidic filter
- Optofluidic integrated Mach-Zehnder interferometer
- Integrated optofluidic ring resonator
- Hybrid silicon-PDMS optofluidic platform

Additional Info

Water pollutants monitoring

Biochemical and biomedical sensors

    G. Testa, Y. Huang, P. M. Sarro, L. Zeni, and R. Bernini, "Integrated silicon optofluidic ring resonator”, Applied Physics Letters , vol. 97, 131110, 2010.

    G. Testa, Y. Huang, P. m. Sarro, L. Zeni, and R. Bernini, "High visibility optofluidic Mach-Zehnder interferometer”, Optics Letters, vol.35, no.10, pp.1584-1586, 2010.

    G. Testa, Y. Huang, L. Zeni, P. M. Sarro and R. Bernini, “Liquid core ARROW waveguides by Atomic Layer Deposition”, IEEE Photon. Technol. Lett., vol.22, pp.616–618, 2010.

    R. Gravina, G. Testa, R. Bernini, “Perfluorinated Plastic Optical Fiber Tapers for Evanescent Wave Sensing”,  Sensors, vol.9, pp.10423-10433, 2009.

    R. Bernini, G. Testa, L. Zeni, P.M. Sarro, “2x2 Optofluidic multimode interference coupler”, IEEE J. Select. Topics Quantum Electron., vol.15, pp.1478-1484. 2009.

    R. Bernini, G. Testa, L. Zeni, P.M. Sarro “Integrated optofluidic Mach-Zehnder interferometer based on liquid core waveguides”, Applied Physics Letters, vol. 93, 011106, 2008.

    R. Bernini, E. De Nuccio, A. Minardo, L. Zeni and P.M. Sarro,“Liquid-core/liquid-cladding integrated silicon ARROW waveguides”, Optics Communications, vol.281, pp.2062-2066, 2008

    R. Bernini, E. De Nuccio, A. Minardo, L. Zen, P. M. Sarro, “2D MMI devices based on integrated hollow ARROW waveguides”, IEEE J. Select. Topics Quantum Electron., vol.13, no.2, pp.194-201, 2007.

    R. Bernini . E. De Nuccio, F. Brescia, A. Minardo, L. Zeni, P. M. Sarro, R. Palumbo, M. R. Scarfi, “Development and characterization of an integrated silicon micro flow cytometer”, Analytical and Bioanalytical Chemistry, vol.386, pp.1267–1272, 2006.

    A.Minardo, R. Bernini, F. Mottola and L. Zeni “Optimization of metal-clad waveguides for sensitive fluorescence detection”, Optics Express, vol. 14, No. 8, pp.3512-3527, 2006. Scelto per The virtual journal  for biomedical optics Vol. 1, Iss. 5 -- May 5, 2006.


      Technical University of Delft

      Seconda Università di Napoli

      Università di Firenze