Dome-shaped whispering gallery mode laser for remote wall temperature sensing

Area of Science:

• Optics and Photonics
• Materials Science
• Sensing Technology

Background:

• Whispering gallery mode (WGM) microlasers offer high sensitivity for sensing applications.
• Remote temperature sensing is crucial in various industrial and environmental monitoring scenarios.
• Developing robust and efficient microlaser-based sensors is an active area of research.

Purpose of the Study:

• To investigate the performance of dome-shaped microlasers for remote wall temperature sensing.
• To evaluate the impact of different polydimethylsiloxane (PDMS) encapsulation methods on microlaser stability and sensitivity.
• To determine the temperature sensitivity and resolution of the developed sensing system.

Main Methods:

• Fabrication of dome-shaped microlasers using Norland blocking adhesive (NBA 107) doped with rhodamine 6G and ethanol.
• Experimental setup involving remote pumping of the microlaser with a Q-switched Nd:YAG laser.
• Testing two configurations: resonator on a PDMS layer and resonator encapsulated in PDMS.
• Characterization of optical quality factor and temperature-dependent spectral shifts.

Main Results:

• Achieved an average optical quality factor of 10⁴ for both resonator configurations.
• Demonstrated a temperature sensitivity of approximately 0.06 nm/°C.
• Obtained a temperature resolution of 1°C, limited by the experimental setup's resolution.

Conclusions:

• Dome-shaped WGM microlasers are viable for remote wall temperature sensing.
• Both tested PDMS configurations yielded comparable temperature sensitivity and resolution.
• Further improvements in experimental resolution are needed to fully exploit the sensor's potential.