High-precision micro-displacement sensing based on an optical filter and optoelectronic oscillators

Area of Science:

• Optoelectronics
• Precision Measurement
• Optical Sensing

Background:

• Accurate micro-displacement sensing is crucial in various scientific and industrial applications.
• Existing methods often involve complex setups and lack self-calibration capabilities.
• Optoelectronic oscillators (OEOs) offer potential for high-sensitivity measurements.

Purpose of the Study:

• To propose and experimentally demonstrate a high-precision micro-displacement sensing system.
• To leverage optical filters and OEOs for a simplified and self-calibrating measurement scheme.
• To achieve enhanced measurement resolution and precision.

Main Methods:

• Utilizing an optical filter to separate measurement and reference optoelectronic oscillator (OEO) loop carriers.
• Implementing a common path structure where OEO loops share optical/electrical components.
• Employing a magneto-optic switch for alternate oscillation of measurement and reference OEOs, enabling self-calibration.

Main Results:

• Achieved a micro-displacement sensitivity of 312.058 kHz/mm.
• Demonstrated a measurement resolution of 356 picometers (pm).
• Obtained a measurement precision of less than 130 nanometers (nm) over a 19 mm range.

Conclusions:

• The proposed optical filter and OEO-based system enables high-precision micro-displacement sensing.
• Self-calibration is effectively achieved by alternately oscillating OEO loops, simplifying the system architecture.
• The experimental results validate the system's capability for sensitive and precise micro-displacement measurements.