Speckle fields generated with binary diffusers and synthetic pupils implemented on a spatial light modulator.

Area of Science:

• Optics and Photonics
• Digital Holography
• Speckle Metrology

Background:

• Gaussian speckle fields are crucial for applications like optical coherence tomography and microscopy.
• Traditional methods for generating speckle fields often lack dynamic control and require bulky optical components.

Purpose of the Study:

• To develop a novel digital method for generating controllable Gaussian speckle fields.
• To replace conventional components like ground glass diffusers with a more flexible spatial light modulator (SLM) based system.

Main Methods:

• Experimentally generated digitally controllable Gaussian speckle fields using a liquid crystal spatial light modulator (SLM).
• Implemented binary diffusers and synthetic pupils, where the synthetic pupil included a Ronchi phase mask and filtered diffraction orders.
• Displayed the binary diffuser within an aperture on the Ronchi phase mask.

Main Results:

• Successfully replaced the need for ground glass and physical pupils in speckle generation.
• Demonstrated dynamic control over the average speckle size.
• Achieved dynamic control over the statistical independence of generated speckle patterns.
• Showcased dynamic control over the average intensity distribution of the speckle field.

Conclusions:

• The proposed SLM-based system offers a flexible and digitally controllable approach to generating Gaussian speckle fields.
• This technique simplifies speckle generation setups by eliminating the need for physical diffusers and pupils.
• The dynamic control capabilities open new avenues for advanced optical imaging and metrology applications.