Additional filters enhancing the sensitivity of an optical correlator

Area of Science:

• Optics and Photonics
• Metrology

Background:

• Optical correlators are used for size measurements.
• Spatial filters are crucial for defining measurement parameters.
• Sensitivity limitations can impact measurement accuracy.

Purpose of the Study:

• To investigate the impact of additional filters on optical correlator output.
• To derive new filters that increase measurement sensitivity.
• To explore applications in automated production control.

Main Methods:

• Derivation of additional filters using series expansion.
• Implementation of slit filters for linear output.
• Implementation of bandpass filters for quadratic output.
• Experimental validation of filter performance.

Main Results:

• Additional filters significantly enhance measurement sensitivity.
• Slit filters create a linear relationship between output and size deviation.
• Bandpass filters produce a quadratic output characteristic.
• Experimental results confirm the effectiveness of the derived filters.

Conclusions:

• Additional filters improve the sensitivity of optical correlators for size measurement.
• The developed filters offer precise control over output characteristics.
• This technique is applicable to measuring both rectangular and circular dimensions.
• The method holds potential for applications in automatic production control.