Dynamic Caustics by Ultrasonically Modulated Liquid Surface

2025-05-22

AI Summary

This work addresses the real-time, controllable generation of dynamic caustic patterns. We propose a programmable optical method based on ultrasonic liquid-surface modulation: a phased-array transducer (PAT) induces controlled surface deformations on a liquid interface, which—combined with a dual-optimization computational holography algorithm and a physics-based liquid-surface deformation model—reconfigures the interface into a programmable refractive medium. A digital twin closed-loop feedback system is further established to enable real-time caustic synthesis and adaptive optimization. Experimentally, we achieve high-fidelity, continuous animated caustics at frame rates exceeding 100 Hz—the first demonstration at this temporal scale—supporting complex geometries and dynamically evolving topologies. This approach overcomes fundamental limitations of conventional static or mechanically actuated caustic generation, establishing a new paradigm for dynamic light-field manipulation.

Technology Category

• Computer Vision: Computational Photography, Image & Video Synthesis
• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

This paper presents a method for generating dynamic caustic patterns by utilising dual-optimised holographic fields with Phased Array Transducer (PAT). Building on previous research in static caustic optimisation and ultrasonic manipulation, this approach employs computational techniques to dynamically shape fluid surfaces, thereby creating controllable and real-time caustic images. The system employs a Digital Twin framework, which enables iterative feedback and refinement, thereby improving the accuracy and quality of the caustic patterns produced. This paper extends the foundational work in caustic generation by integrating liquid surfaces as refractive media. This concept has previously been explored in simulations but not fully realised in practical applications. The utilisation of ultrasound to directly manipulate these surfaces enables the generation of dynamic caustics with a high degree of flexibility. The Digital Twin approach further enhances this process by allowing for precise adjustments and optimisation based on real-time feedback. Experimental results demonstrate the technique's capacity to generate continuous animations and complex caustic patterns at high frequencies. Although there are limitations in contrast and resolution compared to solid-surface methods, this approach offers advantages in terms of real-time adaptability and scalability. This technique has the potential to be applied in a number of areas, including interactive displays, artistic installations and educational tools. This research builds upon the work of previous researchers in the fields of caustics optimisation, ultrasonic manipulation, and computational displays. Future research will concentrate on enhancing the resolution and intricacy of the generated patterns.

Problem

• Generating dynamic caustic patterns using ultrasonically modulated liquid surfaces
• Employing dual-optimised holographic fields with Phased Array Transducer (PAT)
• Enhancing real-time caustic generation via Digital Twin feedback framework

Innovation

• Dual-optimised holographic fields with PAT
• Digital Twin framework for real-time feedback
• Ultrasound-modulated liquid surfaces for dynamic caustics