Chongfan Technology
News
13
2026
-
04
All-Optical Polarization Control in Time-Varying Low-Refractive-Index Films Based on Plasma Symmetry Breaking
Author:
A team led by Marcello Ferrera at Heriot-Watt University has proposed an all-optical scheme that employs femtosecond pumping of low-refractive-index, subwavelength isotropic thin films to achieve ultrafast control over birefringence, dichroism, and optical activity on a single-material platform. When probed at the material’s cross-wavelength, linearly polarized pump light induces transient phase delays of up to 0.1π μm⁻¹ between the appropriate orthogonal components, accompanied by a dichroic absorption ratio of approximately 1.2. In contrast, circularly polarized excitation gives rise to nonreciprocal optical activity, resulting in polarization rotation rates as high as 1.1° μm⁻¹. These transient values exceed by several orders of magnitude those reported for other nanophotonic systems and can be quantitatively reproduced using a dedicated theoretical model, underscoring the critical role of time-dependent damping in photoexcited carrier plasmas. By integrating experimental and theoretical investigations, the authors have established a reconfigurable, deep-subwavelength polarization-control mechanism operating on subpicosecond timescales. This approach is highly suitable for compact ultrafast modulators, dynamic metasurfaces, and tunable nonreciprocal photonic devices, with broad application prospects in quantum optics, ultrafast logic, and time-resolved sensing.
The research findings were published in Nature Photonics on April 3, 2026, under the title “All-optical polarization control in time-varying low-index films via plasma symmetry breaking.”
Figure 1: Conceptual Comparison of Structural and Temporal Approaches to Polarization Control
Figure 2: Experimental Optical Path
Figure 3: Ultrafast Nonlinear Polarization Coupling in Time-Dependent AZO Thin Films
Figure 4: Extended Analysis of Dichroism and Birefringence
Figure 5: Pump-induced transient optical activity and global polarization transformation on the Poincaré sphere
Figure 6: Schematic illustration of the full-wave simulation of the coupled equations and the material polarization under circularly polarized pumping.
Source: Optical World
LATEST NEWS
Thank you for visiting the official website of Chongfan Technology. If you have cooperation intentions or suggestions, please contact us through the following methods, and we will reply as soon as possible, thank you!
Address: Room 403, Building 6, Phase III of R&D, No. 36 Xiyong Avenue, High tech Zone, Chongqing, China.
Telephone: +86-13658337211
E-mail: Sales@cfkeji.net
Website: www.cfkeji.net
Mobile Version
