ABSTRACT
Two subfamilies of concave grating superstationary anastigmatic mounts that provide minimum chromatic aberrations are described. The obtained approximate formulas can be used to design flat-field spectrographs and multi/demultiplexers for optical communication networks. Two specific mounts and their performance are presented.
ABSTRACT
The general equations for parameters of concave grating mounts that provide stationary and superstationary astigmatism at the wavelength of correction are derived for the first time, to the best of our knowledge. These can be used to design grating multi/demultiplexers for wavelength-division multiplexed optical communication systems and high-resolution, narrow-band spectrographs. Important special cases of stationary anastigmatic mounts and their performance are presented.
ABSTRACT
The concave grating stationary anastigmatic spectrograph has been modified into a novel retroreflective scheme by introducing a convex mirror concentric to the intermediate image. This provides double dispersion, diffraction-limited imaging of a long entrance slit, and substantial compensation of the stationary chromatic astigmatism. One can realize 140 independent multi/demultiplexers with 160 channels each simultaneously in the described device for optical network applications. Ray-tracing spot diagrams are presented.
ABSTRACT
A simple equation for the parameters of the Rowland circle grating mount is derived that ensures that the astigmatism and the meridional spherical aberration are stationary at the wavelength of correction. This is important in optimizing the design of grating multiplexers-demultiplexers and cross connects in wavelengthdivision multiplexed networks and high-resolution narrow-band spectrographs. An analysis of aberrations in three-dimensional and planar two-dimensional optical schemes is presented, and it is shown that in the wavelength range of 1530-1570 nm diffraction-limited performance can be achieved for 160 channels in a three-dimensional multiplexer-demultiplexer and for more than 800 channels for a planar free-space scheme.
ABSTRACT
A novel multiplexing scheme for dense holographic storage in photorefractive crystals, spatioangular multiplexing, is described in detail. Compared with spatial multiplexing, spatioangular multiplexing increases the storage capacity by fully utilizing the volume of the storage medium. On the other hand, spatioangular multiplexing reduces the number of holograms overlapping any one hologram in a given volume and so increases the diffraction efficiency achievable as compared with angular multiplexing. Using this scheme, we succeeded in storing 756 high-resolution patterns in an Fe:LiNbO(3) crystal of volume 1 cm(3), with an average diffraction efficiency of 0.5%. This large database is designed for practical use in a novel associative-memory system, called a high-order feedback neural network.
ABSTRACT
We propose the use of a computer-generated hologram that combines a fanout and focusing element that can be used to perform an optical perfect-shuffle interconnection. The hologram is designed by calculation of the interference fringes between diverging waves from four point sources and a reference plane wave. With this element we show experimentally the resulting perfect-shuffle pattern. The use of the computer-generated hologram makes it easy to implement a planar optical perfect-shuffle interconnect, which is compact, has low aberration, and is easy to align. The planar optics configuration for a perfect-shuffle interconnection network is also discussed.
ABSTRACT
We propose a planar optical configuration for implementation of crossover interconnects. The planar overlay allows two-dimensional pixel arrays located on a wafer-scale integrated circuit to be interconnected in a compact and vibrationally robust configuration. By using an acute-angle microprism array with apex angles of 70.52 deg fabricated on a silicon substrate, we show the experimental result of the crossover interconnections. Some practical limits of the planar optical crossover interconnections are also discussed.
ABSTRACT
A novel noninverting optoelectronic logic device using a GaAs/AlGaAs multiple-quantum-well modulator is demonstrated that combines electronic nonlinearity with optical input and output and is bistable. The device is bistable but displays hard limiting and an optical gain of 12.