Autofocusing properties of partially coherent caustic beams

Area of Science:

• Optics and Photonics
• Catastrophe Optics
• Coherence Engineering

Background:

• Partially coherent caustic (autofocusing) beams are vital for optical applications in complex, scattering environments.
• Adjusting beam coherence enhances performance, but reduced coherence typically increases diffraction, weakening focusing ability.
• Existing methods face limitations in balancing coherence and focusing for optimal performance in adverse conditions.

Purpose of the Study:

• To address the limitations of reduced coherence in focusing ability for optical beams.
• To generate and characterize a novel circular swallowtail beam on an incoherent background (CSBIB).
• To investigate the autofocusing properties of CSBIB under varying coherence levels.

Main Methods:

• Generated CSBIB through the incoherent superposition of weighted cosine modes.
• Investigated the beam's autofocusing behavior using truncated CSBIB.
• Analyzed the impact of decreased coherence on focal length and maximum intensity.

Main Results:

• The truncated CSBIB demonstrated enhanced autofocusing properties under low coherence conditions.
• Decreasing coherence shortened the focal length and increased maximum intensity of the CSBIB.
• CSBIB outperformed traditional partially coherent caustic beams in autofocusing under low coherence.

Conclusions:

• The developed CSBIB offers improved autofocusing capabilities by leveraging low coherence.
• This work presents a new approach combining catastrophe optics and coherence engineering for advanced beam design.
• CSBIB provides a promising solution for optical applications in scattering media and engineered partial coherence environments.