Controllable rotating Gaussian Schell-model beams.

Area of Science:

• Optics and Photonics
• Wave Propagation

Background:

• Optical twists involve the rotation of light structures along the beam axis.
• Partially coherent fields can exhibit quadratic twist phases, leading to optical twists.
• Existing twisted Gaussian Schell-model beams are based on rotationally invariant cross-spectral density functions.

Purpose of the Study:

• To introduce a new class of partially coherent beams with rotating spectral density and degree of coherence during propagation.
• To explore the underlying physics and distinctive twist effects of these novel beams.
• To demonstrate the potential for greater than 90-degree beam twist for flexible tailoring.

Main Methods:

• Construction of partially coherent beams without relying on rotationally invariant cross-spectral density functions.
• Analysis of the propagation dynamics of spectral density and degree of coherence.
• Theoretical investigation of the resulting optical twist effects.

Main Results:

• A new family of partially coherent beams exhibiting rotation in spectral density and coherence during propagation was successfully constructed.
• These beams demonstrate distinct twist effects, differing from previously reported twisted Gaussian Schell-model beams.
• The synthesized beams can achieve twist angles exceeding 90 degrees, offering enhanced control.

Conclusions:

• The study introduces a novel class of rotating partially coherent beams with unique physical properties and twist effects.
• These findings expand the understanding of optical twists and provide greater flexibility in manipulating beam properties.
• The research may inspire new optical applications and further investigations into twist phase phenomena.