Grating-coupled surface plasmon resonance on bulk stainless steel

Area of Science:

• Materials Science
• Optics and Photonics
• Surface Science

Background:

• Surface Plasmon Resonance (SPR) is a label-free optical technique used for detecting surface interactions.
• Grating-coupling is a method to excite SPR at wavelengths not accessible by traditional prism-based methods.
• Stainless steel offers a robust and cost-effective substrate for sensor development.

Purpose of the Study:

• To demonstrate grating-coupled SPR using one-dimensional gratings on stainless steel.
• To investigate the influence of incident angle and light polarization on SPR characteristics.
• To compare experimental SPR results with theoretical predictions.

Main Methods:

• Fabrication of one-dimensional gratings on bulk stainless steel via imprinting and electrochemical etching.
• Characterization of SPR using varying incident angles and light polarization states (TM and TE).
• Analysis of SPR peak wavelengths and light coupling efficiency.

Main Results:

• Demonstrated grating-coupled SPR on stainless steel.
• Observed polarization-dependent SPR absorption: TM polarization showed two peaks when incident light was orthogonal to grooves.
• TE-polarized light showed a single resonance peak when incident light was parallel to grooves.
• SPR wavelength dependence on incident angle agreed well with theoretical calculations.

Conclusions:

• Successful fabrication of grating-coupled SPR sensors on stainless steel.
• Understanding of polarization and angle-dependent SPR behavior is crucial for sensor design.
• The developed method provides a viable approach for creating SPR sensors on metallic substrates.