Miniaturized fiber taper reflective interferometer for high temperature measurement

Area of Science:

• Photonics and Optical Sensing
• Materials Science
• Fiber Optic Technology

Background:

• High-temperature sensing is crucial for various industrial applications.
• Existing sensors often face limitations in size, harsh environment durability, and cost.
• Miniaturization and robust design are key challenges in developing advanced optical sensors.

Purpose of the Study:

• To present an ultra-small, all-silica high-temperature sensor.
• To demonstrate a novel Fabry-Perot modal interferometer (FPMI) design for temperature sensing.
• To evaluate the performance of the FPMI sensor in harsh environments.

Main Methods:

• Fabrication of a micro-cavity (approx. 4.4 microm) within a fiber taper probe (<10 mum diameter).
• Utilized a single-mode-multimode fiber configuration for the sensing head, eliminating the need for splicing.
• Leveraged the interference between fundamental and high-order modes reflected from the end-faces for sensing.

Main Results:

• Achieved an ultra-small sensor size (<10 mum diameter).
• Demonstrated a temperature sensitivity of approximately 20 pm/°C near 1550 nm wavelength.
• Confirmed the sensor's capability to operate in environments with ultra-large temperature gradients.

Conclusions:

• The developed FPMI sensor is highly suitable for high-temperature measurements in harsh environments.
• Its miniaturized size and robust all-silica construction offer significant advantages over conventional sensors.
• The novel fiber configuration without splicing simplifies fabrication and enhances reliability.