Laser differential reflection-confocal focal-length measurement

Area of Science:

• Optical Metrology
• Lens Characterization
• Precision Measurement

Background:

• Accurate lens focal length measurement is critical for optical system performance.
• Existing methods face limitations in accuracy and anti-interference capabilities.

Purpose of the Study:

• To introduce a new high-accuracy method for measuring lens focal length.
• To demonstrate the effectiveness of the proposed laser differential reflection-confocal focal-length measurement (DRCFM) technique.

Main Methods:

• Utilizes weak reflected light from the lens's last surface to determine vertex position.
• Employs differential confocal technology for precise identification of lens focus and surface vertex.
• Leverages laser differential reflection-confocal focal-length measurement (DRCFM) for focal length determination.

Main Results:

• The DRCFM method achieves high accuracy in focal length measurement.
• Demonstrates strong anti-interference capabilities compared to existing techniques.
• Experimental results show a relative measurement error of less than 10 ppm.

Conclusions:

• The proposed DRCFM method provides a significant advancement in lens focal length metrology.
• DRCFM offers a reliable and accurate solution for optical component characterization.
• The technique is suitable for applications demanding high precision and stability.