Laser heterodyne interferometric signal processing method based on rising edge locking with high frequency clock...

Area of Science:

• Optics and Photonics
• Metrology
• Digital Signal Processing

Background:

• Laser heterodyne interferometry is crucial for precise measurements.
• Traditional methods face limitations in accuracy and stability.
• Existing phase measurement techniques can be susceptible to noise and errors.

Purpose of the Study:

• To introduce a novel phase measurement method for laser heterodyne interferometers.
• To enhance measurement accuracy, anti-interference capabilities, and stability.
• To achieve high-speed and nanometer-resolution displacement measurements.

Main Methods:

• A novel phase measurement method combining rising-edge locked signal processing and digital frequency mixing.
• Rising-edge locked signal processing utilizes a high-frequency clock to lock signal edges, improving steepness and eliminating counting errors.
• Digital frequency mixing employs digital signals instead of conventional analog mixing for enhanced performance.

Main Results:

• The proposed method significantly improves measurement accuracy and stability.
• Enhanced anti-interference capabilities were demonstrated.
• Feasibility was verified through experiments for large displacement measurements with high speed and nanometer resolution.

Conclusions:

• The novel phase measurement method offers superior performance for laser heterodyne interferometers.
• The digital signal processing approach enhances precision and reliability in metrology.
• This technique is suitable for demanding applications requiring high-speed, high-resolution displacement sensing.