Combined Displacement and Angle Sensor with Ultra-High Compactness Based on Self-Imaging Effect of Optical...

Area of Science:

• Optoelectronics
• Nanotechnology
• Metrology

Background:

• Accurate measurement of linear and angular displacement is crucial for precision engineering and manufacturing.
• Existing sensors often lack compactness or the ability for simultaneous multi-dimensional measurements.
• Optical microgratings offer potential for miniaturized sensing solutions.

Purpose of the Study:

• To propose and demonstrate an ultracompact, combined sensor for simultaneous linear and angular displacement measurement.
• To leverage the self-imaging effect of optical microgratings for synchronous sensing.
• To evaluate the sensor's performance in terms of resolution and sensitivity.

Main Methods:

• Utilized a two-grating structure based on the self-imaging effect of optical microgratings.
• Investigated optical transmission properties through theoretical analysis and simulations.
• Experimentally validated the synchronous measurement of linear displacement (phase change) and angular displacement (amplitude change).

Main Results:

• Demonstrated a sinusoidal relationship between optical transmission and linear displacement.
• Observed a decrease in transmission amplitude with increasing pitch angle, enabling angular measurement.
• Achieved a linear displacement resolution of 4 nm and angular sensitivity of 0.26 mV/arcsec within ±1°.

Conclusions:

• The proposed sensor enables ultracompact, synchronous measurement of linear and angular displacement using a single micrograting structure.
• The common-path design, free from additional optical components, enhances compactness and robustness.
• The sensor shows significant potential for applications in integrated mechanical positioning and semiconductor fabrication.