High-sensitivity, fast-response ethanol gas optical sensor based on a dual microfiber coupler structure with the...

Area of Science:

• Photonics
• Chemical Sensing
• Materials Science

Background:

• Optical sensors offer high sensitivity and immunity to electromagnetic interference.
• The Vernier effect enhances spectral shifts in coupled optical systems.
• Developing sensitive and selective ethanol sensors is crucial for environmental monitoring and safety.

Purpose of the Study:

• To develop a high-sensitivity ethanol gas sensor.
• To leverage the Vernier effect for enhanced spectral response.
• To investigate the sensor's performance characteristics, including responsivity and response/recovery times.

Main Methods:

• Fabrication of a sensor system using two parallel microfiber couplers.
• Coating the microfiber coupler waist with Nile red and polymethyl methacrylate for ethanol interaction.
• Analyzing the superimposed output spectrum and its shift in response to ethanol concentration.
• Utilizing variation rate conversion point characteristics to determine responsivity.

Main Results:

• The sensor exhibited a symmetrical envelope curve in its output spectrum.
• A high responsivity of 160 pm/ppm was achieved by tracking reference peaks.
• The sensor demonstrated fast response and recovery times, on the order of seconds.
• The spectral shift of the envelope curve correlated with changes in ethanol concentration.

Conclusions:

• The microfiber coupler-based sensor effectively detects ethanol gas with high sensitivity.
• The Vernier effect significantly enhances the sensor's responsivity to ethanol.
• The sensor's rapid response and recovery times make it suitable for real-time monitoring applications.