Universal sensitivity of speckle intensity correlations to wavefront change in light diffusers

Area of Science:

• Optics and Photonics
• Interferometry
• Wavefront Sensing

Background:

• Traditional interferometers often require complex setups.
• Speckle patterns arise from light scattering through diffusers.
• Retrieving phase information from scattered light is challenging.

Purpose of the Study:

• To demonstrate that a light diffuser can function as a simple interferometer.
• To show that speckle pattern correlations are independent of the diffuser properties.
• To confirm that these correlations solely depend on the incident beam's phase changes.

Main Methods:

• Utilizing numerical simulations based on random matrix theory.
• Employing an experimental setup with a microfluidic channel for pressure-driven wavefront deformation.
• Analyzing spatial intensity correlations of speckle patterns generated by a coherent beam passing through a light diffuser.

Main Results:

• Spatial intensity correlations of speckle patterns are independent of the light diffuser.
• These correlations are solely determined by the phase changes of the incident beam.
• Experimental and numerical results confirm the universal sensitivity of speckle intensity correlations.

Conclusions:

• A light diffuser can serve as a compact and simple interferometer.
• This technique allows for the retrieval of phase information from optical fields.
• Potential applications exist in metrology, analytical chemistry, and biomedicine.