Wide-field interferometric measurement of a nonstationary complex coherence function

Area of Science:

• Optics and Photonics
• Optical Metrology
• Coherence Theory

Background:

• The spatial coherence function (SCF) provides more information than intensity distribution alone.
• Accurate SCF measurement is crucial for optical sensing and imaging applications.
• Existing methods may lack speed or quantitative accuracy for complex fields.

Purpose of the Study:

• To demonstrate an efficient two-step procedure for measuring the full-field complex coherence function.
• To develop a method capable of characterizing spatially inhomogeneous fields.
• To enable precise analysis of optical fields and their source properties.

Main Methods:

• Utilized an optimized wavefront shearing interferometer design.
• Employed a two-step measurement procedure for comprehensive characterization.
• Validated measurement precision against numerical Fresnel calculations.

Main Results:

• Successfully measured the full-field complex coherence function efficiently and accurately.
• Demonstrated characterization of spatially inhomogeneous fields over an extended angular domain.
• Confirmed high measurement precision through agreement with numerical simulations.

Conclusions:

• The developed method provides a fast and quantitatively accurate measurement of the complex coherence function.
• The instrument's sensitivity and range allow reliable differentiation of coherence functions based on source modifications.
• This technique advances optical sensing and imaging by enabling detailed characterization of optical fields.