Technologies on Display
D2 - Photonic Sensors based on Surface
Plasmon Resonance Effect
Surface plasmon resonance (SPR) is an intriguing effect associated with
interaction between EM wave and metal surface. When an optical beam hits a
metal-dielectric interface at a specific angle, some of the optical energy
will be transferred. It forces the free electrons to move along with the
incident optical wave. ¡§Surface Plasmons¡¨ thus refer to such oscillations of
free electrons in the metal film.
The
existence of SPR in metal film (typically gold) makes it ideal for detecting
material variations within a thin region close to the film surface. This
project aims to exploit the special properties of SPR for sensor
applications. At CUHK we focus on detecting the optical phase. This novel
approach has been shown to be at least one order of magnitude more accurate
than conventional methods. To further increase instrument stability we have
also developed a differential technique to remove unwanted drifts caused by
environmental disturbance.
Applications
- Medical care
- Consumer health products
- Chemical industry
- Pharmaceutical/drugs
- Environmental/pollution monitoring
- Semiconductor/wafer fabrication
Features
- High sensitivity (up to 4 x 10-8 refractive index unit)
- Excellent stability from differential measurement
- Biomolecules such as antibody, DNA and protein can be detected
- Capable of measuring reaction rate
- Label-free sensing and real-time measurement
Principal Investigator
Prof. Aaron Ho
Department of Electronic Engineering
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