Field of view expansion for 3-D holographic display using a single spatial light modulator with scanning reconstruction light

Increasing the field of view of a holographic display while maintaining adequate image size is a difficult task. To address this problem, we designed a system that tessellates several sub-holograms into one large hologram at the output. The sub-holograms we generate is similar to a kinoform but without the paraxial approximation during computation. The sub-holograms are loaded onto a single spatial light modulator consecutively and relayed to the appropriate position at the output through a combination of optics and scanning reconstruction light. We will review the method of computer generated hologram and describe the working principles of our system. Results from our proof-of-concept system are shown to have an improved field of view and reconstructed image size. ©2009 IEEE.

Instability Of Crack Propagation In Brittle Bulk Metallic Glass

The instability of the crack tip in brittle Mg-based bulk metallic glass (BMG) is studied. The formation of various fractographic surfaces of the BMG is associated with the instability of the fluid meniscus, which is due to viscous fluid matter being present on the fracture process zone. Depending on the values of the wavelength of the initial perturbation of the fluid meniscus and the local stress intensity factor, different fracture surface profiles, i.e. a dimple-like structure, a periodic corrugation pattern and a pure mirror zone are formed. The fractographic evolution is significantly affected by the applied stress. A decreased fracture Surface roughness is observed under a low applied stress. An increased fracture surface roughness, which has frequently been reported by other researchers, is also observed in the present studies under a high applied stress. Unique fractographic features are attributed to the non-linear hyperelastic stiffening for less softening) mechanism. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Study of the surface structure of butterfly wings using the scanning electron microscopic moire method

Scanning electron microscopic (SEM) moire method was used to study the surface structure of three kinds of butterfly wings: Papilio maackii Menetries, Euploea midamus (Linnaeus), and Stichophthalma how-qua (Westwood). Gratings composed of curves with different orientations were found on scales. The planar characteristics of gratings and some other planar features of the surface structure of these wings were revealed, respectively, in terms of virtual strain. Experimental results demonstrate that SEM moire method is a simple, nonlocal, economical, effective technique for determining which grating exists on one whole scale, measuring the dimension and the whole planar structural character of the grating on each scale, as well as characterizing the relationship between gratings on different scales of each butterfly wing. Thus, the SEM moire method is a useful tool to assist with characterizing the structure of butterfly wings and explaining their excellent properties. (c) 2007 Optical Society of America.