Compact freeform illumination design by deblurring the extended sources

Illumination is the deliberate utilization of light to realize practical or aesthetic effects. The designers combine with the environmental considerations, energy-saving goals, and technology advances with fundamental physics to develop lighting solutions to satisfy all of our ever-changing needs. Achieving highly efficient and precise control of the energy output of light sources while maintaining compact optical structures is the ultimate goal of illumination design. To realize miniaturized and lightweight luminaires, the design process must consider the extents of light sources. However, the illumination design for extended sources is still a challenging and unsolved problem. Here, we propose a method to design ultra-performance illumination optics enabled by freeform optical surfaces. The proposed method is very general with no limitations of far-field approximation and Lambertian luminescent property. We demonstrate the feasibility and efficiency of the proposed method by designing several freeform lenses realizing accurate and highly efficient illumination control as well as ultra-compact structures

Paraxial design of four-component zoom lens system with fixed distance between focal points by matrix optics

In this paper, we propose a systematic approach to design a four-component zoom system with fixed spacing between focal points based on matrix optics. Since the more complex model the higher degree of freedom it has, the task of determining the zoom trajectory is meaningful and challenging. The elements of the system matrix imply the working state of the optical system, and axial displacement equation for the desired zoom system are derived by restricting specific matrix elements. Properly selected trajectory of the particular component described by means of a parametric function can make the model become solvable explicitly. Then the paraxial design problem is transformed into the optimization of these parameters with regard to the merit functions encompassing the primary aberration terms, compactness, smoothness of the trajectories. We adopt Particle Swarm Optimization (PSO) algorithm to globally optimize the parameters to retrieve the optimum zoom trajectory in specific design criteria. The proposed method is demonstrated through two numerical examples under different configurations. The simulation results demonstrate that our proposed method can be a practical and powerful tool for paraxial design of complex multi-group zoom optical systems

Multi-surface catadioptric freeform lens design for ultra-efficient off-axis road illumination

We propose a novel design methodology to tackle the multi-surface catadioptric freeform lens design for off-axis road illumination applications based on an ideal source. The lens configuration contains an analytic refractive entrance surface, an analytic total internal reflective (TIR) surface and two freeform exit surfaces. A curl-free energy equipartition is established between the source and target plane and divided to implement the composite ray mapping mechanism. Furthermore, the analytic TIR surface and refractive entrance surface are optimized for the minimal Fresnel losses and surface error based on genetic algorithm (GA). The results show a significant improvement on illuminance uniformity and ultra-high transfer efficiency compared to our proposed result in [Zhu et al., Opt. Exp. 26, A54-A65 (2018)]

Automated first-order design of double-sided telecentric zoom systems based on PSO algorithms

In this paper, we propose a new approach to automatically retrieve the first-order design of double-sided telecentric zoom systems with high efficiency based on Particle Swarm Optimization (PSO) algorithms. We transform the design problem to realize a zoom lens system with fixed positions of both the front focal point and the rear focal point during zooming. We demonstrate that the proposed algorithm is much more efficient than the Monte Carlo algorithm in designing zoom systems with two fixed foci as well as a given zoom ratio. Furthermore, a compact first-order design of three-component 4X zoom system with two fixed foci is proposed to show the high efficiency and great potential of our proposed algorithm in searching proper first-order configuration for complex optical systems

Surface variation analysis of freeform optical systems over surface frequency bands for prescribed wavefront errors

The surface errors of freeform surfaces reflect the manufacturing complexities and significantly impact the feasibility of processing designed optical systems. With multiple degrees of freedom, freeform surfaces pose challenges in surface tolerance analysis in the field. Nevertheless, current research has neglected the influence of surface slopes on the directions of ray propagation. A sudden alteration in the surface slope will lead to a corresponding abrupt shift in the wavefront, even when the change in surface sag is minimal. Moreover, within the realm of freeform surface manufacturing, variation in surface slope across different frequency bands may give rise to unique surface variation. Within the context of this study, we propose a tolerance analysis method to analyze surface variation in freeform surfaces considering surface frequency band slopes based on real ray data. This approach utilizes real ray data to rapidly evaluate surface variation within a specified frequency band of surface slopes. Crucially, our proposed method yields the capability to obtain system surface variation with significant wavefront aberration, in contrast to previous methodologies. The feasibility and advantages of this framework are assessed by analyzing a single-mirror system with a single field and an off-axis two-mirror system. We expect to integrate the proposed methodology with freeform surface design and manufacturing, thereby expanding the scope of freeform optics