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Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons
Published on: July 21, 2018
Polarization-independent on-axis light coupler for surface plasmon resonance using a concentric chirped grating
Sakoolkan Boonruang1, Mahesh Pitchumani, Waleed S Mohammed
1National Electronics and Computer Technology Center, National Science and Technology Development Agency, Thailand Science Park, Pathumthani, Thailand. sakoolkan.boonruang@nectec.or.th
Optics Letters
|September 3, 2011
Summary
A new optical system uses a special grating for surface plasmon resonance (SPR) sensing. This method enables efficient light coupling and signal detection for broad refractive index sensing applications.
Area of Science:
- Optics and Photonics
- Nanotechnology
- Chemical Sensing
Background:
- Surface Plasmon Resonance (SPR) is a label-free optical sensing technique.
- Conventional SPR systems often require complex optical setups and precise alignment.
- Efficient light coupling and signal extraction are critical for SPR sensor performance.
Purpose of the Study:
- To propose a novel, compact, and polarization-independent light in- and out-coupling mechanism for SPR.
- To demonstrate a broad sensing dynamic range using the proposed system.
- To develop an analytical model for understanding SPR signal behavior.
Main Methods:
- Design and implementation of an integrated high-Numerical Aperture (NA) concentric chirped grating.
- Utilizing the grating for focusing incident light and collimating the reflected SPR signal.
- Employing a CCD array for SPR signal detection.
- Development of an analytical model to predict resonance behavior.
Main Results:
- Achieved a high NA up to 1.47 for efficient light manipulation.
- Demonstrated a broad sensing dynamic range for refractive indices from n=1 to 1.35.
- The analytical model accurately predicted the radial location of SPR resonances and sensitivity to refractive index changes, consistent with ray-tracing simulations.
Conclusions:
- The proposed on-axis, one-element system offers a simplified and effective approach for SPR sensing.
- The integrated grating design enables efficient light coupling and signal extraction.
- The system's broad dynamic range and validated analytical model show significant potential for various sensing applications.
