Axicon is an interesting optical element for its optical properties. This paper presents an approach to dynamically generated tunable axicons with a spatial light modulator (SLM). 256-level phase computer-generated holograms (CGHs) were loaded into the SLM to simulate the positive and negative axicons. The intensity distributions of beams passing through these axicons were analyzed with the principle of blazed grating and Fresnel diffraction; and the diffraction patterns were obtained theoretically in terms of zero-order Bessel beams and annular hollow beams, corresponding to the positive and negative axicons, respectively. Experimental results verified that the diffraction patterns have the same distribution as the real axicon. The types of the axicon and the axicon’s parameters can be easily altered through changing the CGHs.
27 November 2024 in Energy Conversion and Management
The optimization of imaging accuracy and speed is a crucial issue in the development of computer-generated holograms (CGH) for three-dimensional (3D) displays. This paper proposes an optimized iterative algorithm based on the angular spectrum method (ASM) to achieve high-quality holographic imaging across multiple planes. To effectively utilize spatial resources for multi-image reconstruction and mitigate the speckle noise caused by the overlapping of target images, constraint factors are introduced between different layers within the same region. The seeking rule of the constraint factor is also analyzed. By utilizing both constraint factors and variable factors, the presented method is able to calculate phase holograms for target figure imaging at four different planes. Simulation and experimental results demonstrate that the proposed method effectively improves the overall quality of the different planes, thus holding great potential for wide-ranging applications in the field of holography.
1 April 2024 in Journal of Thermophysics and Heat Transfer
As integrated circuit technology continues to advance, clock tree synthesis has become increasingly significant in the design of ultra-large-scale integrated circuits. Traditional clock tree synthesis methods often face challenges such as insufficient computational resources and buffer fan-out limitations when dealing with ultra-large-scale clock trees. To address this issue, this paper proposes an improved clock tree synthesis algorithm called incomplete balanced KSR (IB-KSR). Building upon the KSR algorithm, this proposed algorithm efficiently reduces the consumption of computational resources and constrains the fan-out of each buffer by incorporating incomplete minimum spanning tree (IMST) technology and a clustering strategy grounded in Balanced Split. In experiments, the IB-KSR algorithm was compared with the GSR algorithm. The results indicated that IB-KSR reduced the global skew of the clock tree by 43.4% and decreased the average latency by 34.3%. Furthermore, during program execution, IB-KSR maintained low computational resource consumption.