Bradley Department of Electrical and Computer Engineering

Permanent URI for this community

https://hdl.handle.net/10919/18738
From pervasive computing, to smart power systems, Virginia Tech ECE faculty and students delve into all major areas of electrical and computer engineering. The main campus is in Blacksburg, and the department has additional research and teaching facilities in Arlington, Falls Church, and Hampton, Virginia.

Browse

Browsing Bradley Department of Electrical and Computer Engineering by Subject "0205 Optical Physics"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Off-axis optical scanning holography [Invited]
    Zhang, Yaping; Yao, Yongwei; Zhang, Jingyuan; Liu, Jung-Ping; Poon, Ting-Chung (Optical Society of America, 2022-02-01)
    Optical scanning holography (OSH) involves the principles of optical scanning and heterodyning. The use of heterodyning leads to phase-preserving, which is the basic idea of holography. While heterodyning has numerous advantages, it requires complicated and expensive electronic processing. We investigate an off-axis approach to OSH, thereby eliminating the use of heterodyning for phase retrieval.We develop optical scanning theory for holographic imaging and show that by properly designing the scanning beam, we can performcoherent and incoherent holographic recording. Simulation results are provided to verify the proposed idea.
  • Thumbnail Image
    Optimal sampled phase-only hologram (OSPOH)
    Tsang, P. W. M.; Liu, J. Ping; Lam, H.; Poon, T. C. (Optical Society of America, 2021-08-02)
    A sampled phase-only hologram (SPOH) is the phase component of the hologram of an object image with pixels being sampled with a periodic grid-cross pattern. The reconstructed image of a SPOH is a sparse image with abundant empty voids and degradation in sharpness and contrast. In this paper we proposed a method based on a new sampling scheme, together with stochastic binary search (SBS), to obtain an optimal sampling lattice that can be applied to generate phase-only holograms with enhanced reconstructed image. Experimental results show that with our proposed method, the fidelity and quality of the reconstructed image are increased.
  • Thumbnail Image
    Polygon-based computer-generated holography: a review of fundamentals and recent progress [Invited]
    Zhang, Yaping; Fan, Houxin; Wang, Fan; Gu, Xianfeng; Qian, Xiaofan; Poon, Ting-Chung (2022-01-31)
    In this review paper, we first provide comprehensive tutorials on two classical methods of polygon-based computer generated holography: the traditional method (also called the fast-Fourier-transform-based method) and the analytical method. Indeed, other modern polygon-based methods build on the idea of the two methods. We will then present some selective methods with recent developments and progress and compare their computational reconstructions in terms of calculation speed and image quality, among other things. Finally, we discuss and propose a fast analytical method called the fast 3D affine transformation method, and based on the method,we present a numerical reconstruction of a computer-generated hologram (CGH) of a 3D surface consisting of 49,272 processed polygons of the face of a real person without the use of graphic processing units; to the best of our knowledge, this represents a state-of-the-art numerical result in polygon-based computed-generated holography. Finally, we also show optical reconstructions of such a CGH and another CGH of the Stanford bunny of 59,996 polygons with 31,724 processed polygons after back-face culling. We hope that this paper will bring out some of the essence of polygon-based computer-generated holography and provide some insights for future research.