Dual-wavelength intensity-modulated Fabry-Perot refractive index sensor driven by temperature fluctuation

Area of Science:

• Optics and Photonics
• Sensor Technology
• Physical Chemistry

Background:

• Refractive index measurement is crucial for chemical analysis and quality control.
• Existing methods may face limitations in accuracy, cost, or environmental sensitivity.

Purpose of the Study:

• To propose and demonstrate a novel in-line Fabry-Perot interferometer for refractive index sensing.
• To evaluate the sensor's accuracy, resolution, and temperature stability.

Main Methods:

• Utilizing a dual-laser system injected into a Fabry-Perot interferometer.
• Analyzing the elliptical distribution of reflected power signals at two wavelengths.
• Calculating refractive index from the ellipse's major axis length.

Main Results:

• Successfully demonstrated refractive index sensing of salt solutions.
• Achieved high accuracy, correlating well with Abbe refractometer measurements.
• Obtained a resolution of 0.0017 and demonstrated temperature insensitivity.

Conclusions:

• The proposed sensor offers a cost-effective, robust, and accurate method for refractive index measurement.
• Its temperature insensitivity and ease of use make it suitable for biological detection, chemical analysis, and environmental monitoring.