Gas environment independent temperature sensor via double-metal surface plasmon resonance

Area of Science:

• Photonics
• Nanotechnology
• Materials Science

Background:

• Optical temperature sensors face noise from environmental refractive index changes.
• High sensitivity often exacerbates this gas environment dependence.

Purpose of the Study:

• To design and fabricate an optical temperature sensor with minimal gas environment dependence.
• To achieve high temperature sensitivity without compromising performance.
• To facilitate generous dimensional tolerance in device fabrication.

Main Methods:

• Fabrication of a sensor using a titanium dioxide grating on a double-metal surface plasmon resonance (SPR) structure.
• Characterization of the proof-of-concept device.
• Testing resonance wavelength shift in various gases (air, CH4, CO2).

Main Results:

• The fabricated sensor achieved a sensitivity of 135 pm/°C.
• Minimal resonance wavelength shift (∼0.004 pm) was observed across different gases.
• The device has a small footprint (15 μm²).

Conclusions:

• The developed optical temperature sensor effectively minimizes gas environment dependence.
• The sensor offers high accuracy for temperature measurements.
• The design is suitable for integrated opto-electronic sensing chips.