Physical Optics, Diffractive Optics, Fourier Optics, Optical Signal Processing

Propagation law of partially coherent vortex beam

Panfeng Ding and Hongliang Ren
We propose the analytic solution of cross-spectral density matrix (CSDM) of a partially coherent vortex beam while propagating. The solution to the propagation law is appropriate for a Gaussian Schell-model vortex beam to any order. It is found that the solution of CSDM of a Gaussian Schell-model be ... [Opt. Eng. 51, 018002 (2012)] published Tue Feb 7, 2012.

Examination of the nonlinear dynamics of a chaotic acousto-optic Bragg modulator with feedback under signal encryption and decryption

Mohammed Al-Saedi and Monish R. Chatterjee
An acousto-optic Bragg cell with first-order feedback, which exhibits chaotic behavior past the threshold for bistability, was recently examined for possible chaotic encryption and recovery of simple messages (such as low-amplitude periodic signals) applied via the bias input of the sound cell drive ... [Opt. Eng. 51, 018003 (2012)] published Mon Feb 6, 2012.

Resonant frequency of triangle split resonant rings

Peng Gao and Chunmin Zhang
The resonant frequency of triangle split resonant rings and metal wires (TSRRs-MWs) is analyzed. The simulated results show that the resonant frequency can be improved and the bandwidth widened by increasing the opening size of TSRRs and by contracting the substrate. Two samples are designed to impl ... [Opt. Eng. 51, 018001 (2012)] published Fri Jan 20, 2012.

Nonlinear joint fractional Fourier-transform correlator based on the threshold-decomposition preprocessing

Qu Wang, Li Chen, Jinyun Zhou, and Qinghua Lin
The morphological joint fractional Fourier transform correlator (MJFTC), as a modified nonlinear joint fractional Fourier transform correlator (JFTC), is introduced in this paper. An optoelectronic setup that can implement such a nonlinear JFTC is advised and constructed. We investigate the correlat ... [Opt. Eng. 50, 118201 (2011)] published Fri Nov 4, 2011.

Retina recognition using compression-based joint transform correlator

Joewono Widjaja and Ubon Suripon
Retina recognition by using joint transform correlator (JTC) with JPEG-compressed target and reference images is proposed. Recognition performance is studied by using retina images with different contrasts employed as test scenes. The simulation results show that regardless of the reference contrast ... [Opt. Eng. 50, 098201 (2011)] published Fri Sep 2, 2011.

Fringe pattern analysis for optical alignment in nanolithography using two-dimentional Fourier transform

Feng Xu, Hu Song, and Shaolin Zhou
A simple but effective phase analysis method for the fringe pattern that occurs in two superposed grating marks applied in the previously designed dual-gratingbased alignment scheme for lithography is proposed. First, the fringe pattern is processed and analyzed using a frequency domain method based ... [Opt. Eng. 50, 088001 (2011)] published Thu Jul 28, 2011.

Nonparaxial propagation of vectorial hollow Gaussian beams diffracted at an annular aperture

Yuanjie Yang, Xiaofeng Li, and Kailiang Duan
Based on the vectorial RaleighSommerfeld diffraction integral, an analytical propagation equation of vectorial nonparaxial hollow Gaussian beams (HGBs) through an annular aperture is derived. The corresponding closed-forms for a circular aperture, a circular black screen, and unapertured case are gi ... [Opt. Eng. 50, 078001 (2011)] published Wed Jul 6, 2011.

Generation of a spiral wave by modified annular slit

Marcelino Anguiano-Morales, Didia P. Salas-Peimbert, and Gerardo Trujillo-Schiaffino
Optical beams of Bessel-type, whose transverse intensity profile remains unchanged under free-space propagation, are called nondiffracting beams. In this paper, we propose a simple and effective method to generate spiral beams whose intensity remains invariant during propagation using amplitude mask ... [Opt. Eng. 50, 078002 (2011)] published Tue Jul 5, 2011.

Optical cryptographic system employing multiple reference-based joint transform correlation technique

Mohammed Nazrul Islam, Mohammad Ataul Karim, Mohammad Showkat Alam, and K. Vijayan Asari
An optical joint transform correlation-based cryptographic system is a used to feed multiple phase-shifted encryption keys into four parallel channels along with a to-be-encrypted signal in the form of an image. The resulting joint power spectra (JPS) signals are phase-shifted and then combined to y ... [Opt. Eng. 50, 068202 (2011)] published Thu Jun 16, 2011.

Color image encryption based on joint fractional Fourier transform correlator

Ding Lu and Weimin Jin
In this paper, an optical color image encryption/decryption technology based on joint fractional Fourier transform correlator and double random phase encoding (DRPE) is developed. In this method, the joint fractional power spectrum of the image to be encrypted and the key codes is recorded as the en ... [Opt. Eng. 50, 068201 (2011)] published Mon Jun 13, 2011.

Novel diffractive optical element: binary photon sieve

Changlun Hou
In this paper, we developed a novel photon sieve consisting of a large number of precisely positioned holes distributed according to an underlying Fresnel zone plate (FZP) geometry, while the holes at transparent and opaque circular rings of the FZP have a pi phase shift. Compared to a conventional ... [Opt. Eng. 50, 068001 (2011)] published Mon Jun 6, 2011.

Short period resonant dual-grating structures for applications to anisotropic color change securities

Yongli Chen and Wenxia Liu
A subwavelength grating with resonant behaviors can be used to exploit security productions with characteristics of anisotropic color variation, i.e., its color has been changed when the grating is rotated on its own plane. In this paper, a novel grating structure with potentials of broadening its s ... [Opt. Eng. 50, 048001 (2011)] published Tue Apr 26, 2011.

On-the-fly writing of a long grating phase mask

Philipp Muller, Yves Jourlin, Colette Veillas, Gerard Bernaud, Yannick Bourgin et al.
A method is demonstrated for writing long grating phase masks, which can be used for patterning large-area (square meter size) submicron-period gratings. The method consist of illuminating a small area transmission grating phase mask by a continous wavetransverse-electric-polarized collimated laser ... [Opt. Eng. 50, 038001 (2011)] published Thu Mar 3, 2011.

Displacement measurement using phase-encoded target joint transform correlator

Ge Peng, Li Qi, Feng Huajun, and Xu Zhihai
A displacement measurement technology using phase-encoded target joint transform correlator (PETJTC) is analyzed in detail. A phase mask is generated electronically and applied to encode the target image. Input images include the phase-encoded target image and the reference image. The joint power sp ... [Opt. Eng. 50, 038201 (2011)] published Tue Mar 1, 2011.

Cryptanalysis of optical encryption schemes based on joint transform correlator architecture

Wan Qin, Xiang Peng, and Xiangfeng Meng
From the perspective of optical cryptanalysis, we propose a method of chosen-plaintext attack against the optical encryption scheme based on joint transform correlator (JTC) architecture. By implementing this attack, an opponent can access the encryption key with the help of the pre-knowledge of a s ... [Opt. Eng. 50, 028201 (2011)] published Tue Feb 1, 2011.

Discrimination between speckle images using diffusers modulated by some deformed apertures: simulation

Abdallah Mohamed Hamed
We investigate new numerical speckle images using diffuser provided with some classes of amplitude apertures. The 1st class is based on circular aperture modulation, the 2nd class assumes modulated elliptical apertures, while the 3rd is devoted to a cardiac, and comet deformed apertures. We have rec ... [Opt. Eng. 50, 018202 (2011)] published Thu Jan 20, 2011.

Four-wave mixing real-time intensity filtering with organic photorefractive materials

Jed Khoury, Bahareh Haji-saeed, Charles L. Woods, John Kierstead, Nasser Peyghambarian et al.
In this paper, we exploit the nonlinearity inherent in four-wave mixing in organic photorefractive materials and demonstrate edge enhancement, contrast conversion, and defect enhancement in a periodic structure. With the availability of these materials, which have large space-bandwidth products, edg ... [Opt. Eng. 50, 018201 (2011)] published Wed Jan 12, 2011.

Design method to enhance the transmittance of a structured lens based on nonperiodic sampling

Yifu Wang, Xiaochun Dong, Guishan Yuan, Guoxing Zheng, and Chunlei Du
On the basis of the work of Chen, Zhou, Luo, and Du [Opt. Lett. 33, 753755 (2008)], we propose a new method using nonperiodic sampling to design a high-transmittance structured lens. The sizes of the holes are decided by the phase requirements, and the holes are arranged with a fixed interval in the ... [Opt. Eng. 50, 018001 (2011)] published Wed Jan 12, 2011.

Resonance and zero scattering of light by spherical photonic clusters: analytical approach

Vitaly V. Prosentsov
Light scattering by finite nanostructures is a topic for modern photonics. The scattering can be investigated numerically by performing memory-demanding and long-running computer simulations. When the electromagnetic field inside the nanostructure is quasiperiodic the computations can be thousand ti ... [Opt. Eng. 49, 128001 (2010)] published Thu Dec 16, 2010.

Photochromic diarylethene-film-based compact all-optical nonlinear joint transform correlator

Hui Jia, Xiujian Li, and Jiankun Yang
We construct an all-optical nonlinear joint transform correlator utilizing the rewritable photochromic diarylethene film, which serves as a joint transform power spectrum recorder. The computer simulations indicate that, with the nonlinear response characteristic of the diarylethene film, the SNR an ... [Opt. Eng. 49, 108201 (2010)] published Mon Oct 25, 2010.

Microstructured design for light trapping in thin-film silicon solar cells

Jian Chen, Qingkang Wang, and Haihua Li
In thin-film silicon solar cells, a flexible optical design for light collection is developed that can lead to zero reflection loss and enhance the optical path length in the absorber layer. In this work, we demonstrate two-filling-factor asymmetric binary gratings on the top of the solar cells and ... [Opt. Eng. 49, 088001 (2010)] published Wed Aug 4, 2010.