Active beam morphology control in chiral media: polarization-dependent tuning of circular cosine-hyperbolic-gaussian light

Abstract

Abstract This work theoretically and numerically investigates the propagation characteristics of circular cosine-hyperbolic Gaussian beams (CiChGBs) in chiral media. Using the Huygens–Fresnel integral combined with polarization-dependent ABCD matrices, we derive analytical expressions that describe the amplitude and phase evolution of the left- and right-circularly polarized (LCP and RCP) components. Numerical simulations show that beam morphology is jointly governed by the decentering parameter b , the beam waist ω 0 , and the chirality strength γ . For small b , the CiChGB remains Gaussian-like with nearly flat wavefronts, while increasing γ slows both phase accumulation and divergence. In contrast, large b produces annular intensity profiles and rapid spatial variations that evolve into centrally peaked beams during propagation; stronger chirality delays this reshaping by introducing polarization-dependent phase shifts. The interplay among b , ω 0 , and γ thus enables active control of intensity patterns and wavefront evolution, opening new avenues for structured-light manipulation, phase-sensitive beam shaping, and chiral sensing in strongly chiral platforms such as planar chiral metamaterials and chiral photonic crystals.