Micro-Cantilever Displacement Detection Based in Optical Fiber Tip.

Area of Science:

• Optoelectronics
• Fiber Optics
• Sensor Technology

Background:

• Contact sensors are crucial for various applications.
• Existing fiber optic sensors have limitations in sensitivity and operating range.
• Integrating microspheres with fiber optic tips offers a new design paradigm.

Purpose of the Study:

• To develop and characterize a novel fiber optic contact sensor.
• To investigate the sensor's performance under different conditions, including temperature and vibration.
• To explore the potential of a microsphere-tip structure for enhanced sensing capabilities.

Main Methods:

• Fabrication of the sensor using an electric arc machine, integrating a microsphere with a fiber optic tip.
• Characterization of sensor operation based on variations in optical path due to tip curvature changes.
• Testing sensor response to temperature and vibration in both parallel and perpendicular configurations.

Main Results:

• The developed sensor demonstrated functionality through changes in output signal correlated with tip curvature.
• Temperature characterization revealed very low sensitivity.
• Vibration characterization showed a higher sensitivity in the perpendicular configuration (0 Hz to 20 kHz) compared to the parallel configuration (1.5 kHz to 7 kHz).
• Linear intensity variation with frequency was observed up to 2 Hz in the perpendicular configuration with a sensitivity of 0.032 ± 0.001 (Hz^-1).

Conclusions:

• The combined microsphere-tip structure is a viable design for fiber optic contact sensors.
• The sensor exhibits promising performance for vibration detection, particularly in the perpendicular configuration.
• The sensor's low temperature sensitivity and wide operating bandwidth make it suitable for diverse applications.