Fraunhofer computer-generated hologram for diffused 3D scene in Fresnel region

Abstract

A Fraunhofer computer-generated hologram (CGH) is proved to be valid in display for three-dimensional (3D) objects from the Fresnel to the far-field region without a Fourier lens for reconstruction. To quickly compute large and complicated 3D objects that consist of slanted diffused surfaces in the Fresnel region, a Fraunhofer-based analytical approach using a basic-triangle tiling diffuser is developed. Both theoretical and experimental results reveal that Fraunhofer CGH can perform the same effects as Fresnel CGH but require less calculation time. Impressive 3D solid effects are achieved in the Fresnel region.

Viewing-angle enlargement in holographic augmented reality using time division and spatial tiling

“…This means we use both the digital and optical methods to impose linear phase factors on the compressed SLMs at the 4f plane and form an ECSA in the horizontal direction. In our previous work, we treated a 3D scene as a combination of triangular patches and have developed a full analytical method for the high-speed CGH computation of trianglebased 3D objects [6,20]. The cylindrical lens pair in the TDST system, however, will introduce deform reconstruction in the x and y directions if directly applying the previous method.…”

“…where , y c , z c ) is the object's centroid in the global coordinate. More detail expressions can be found in our previous paper [6,20].…”

Speckle-suppressed phase-only holographic three-dimensional display based on double-constraint Gerchberg–Saxton algorithm

“…Holographic display is generally implemented based on a computer-generated hologram (CGH) with coherent illumination [1][2][3][4]. In holographic display, speckle noise is a serious problem which severely degrades the quality of the reconstructed image, especially for a phase-only CGH.…”

Novel Optimization Method of Phase-Only Computer-Generated Hologram Using the Phase-Shift Characteristic

“…디지털 홀로그래피 방법은 3차원 물체를 모델링하여 실제 빛 분포를 만들어내는 CGH (Computer Generated Hologram) 와 이를 저장해주는 SLM(Spatial Light Modulator)을 이용한 방식이 주로 이용되고 있다. 이 방식은 필름 방식이 갖던 한 계점을 극복하여, 홀로그램의 무한한 저장 및 재생이 가능한 특징과 손쉽게 3차원 물체 표현이 가능하다는 장점을 가지 고 있다 [4][5][6][7][8][9].…”