Ultrahigh-sensitive and compact temperature sensor based on no-core fiber with PMMA coating

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• Optical fiber sensors offer remote and multiplexed sensing capabilities.
• Miniaturized temperature sensors are crucial for various applications.
• Existing fiber optic temperature sensors face limitations in sensitivity and size.

Purpose of the Study:

• To develop a highly sensitive and compact optical fiber temperature sensor.
• To investigate the relationship between temperature sensitivity and the length ratio of PMMA coating to no-core fiber (NCF).
• To explore a new mechanism for enhancing temperature sensing performance.

Main Methods:

• Fabrication of a PMMA-coated NCF structure.
• Theoretical modeling of the sensor's optical properties.
• Experimental characterization of temperature sensitivity using varying PMMA coating lengths.
• Analysis of the linear response between sensitivity and length ratio.

Main Results:

• A linear relationship was established between temperature sensitivity and the PMMA coating-to-NCF length ratio.
• Ultra-high temperature sensitivity of -9.582 nm/°C was achieved.
• The sensor demonstrated a compact size (5 mm NCF, 3 mm PMMA coating).
• The sensor is simple, compact, and inexpensive to fabricate.

Conclusions:

• The length ratio of PMMA coating to NCF is a critical factor for temperature sensitivity, not just the coating length.
• This new mechanism significantly enhances the sensitivity of miniaturized fiber optic temperature sensors.
• The developed sensor presents a promising solution for high-precision temperature monitoring.