Photorefractive incoherent-to-coherent optical converter

Photorefractive incoherent-to-coherent optical converter.

High-resolution, high-speed photorefractive incoherent-to-coherent optical converter.

We demonstrate a photorefractive incoherent-to-coherent optical converter driven by ultraviolet light that provides a 35-mus response time and an optical resolution of 124 line pairs/mm. The device, implemented in KNbO(3) , operates with a modulating intensity of 85 mW/cm(2) , which corresponds to an optical switching energy per bit of 0.5 pJ. A conversion rate of the order of 90 Gbits/(s cm(2)...

Contrast-reversible photorefractive incoherent-to-coherent optical converter by using an anisotropic strong volume hologram.

In the past several years photorefractive materials have been proposed for use as photorefractive incoherent-to-coherent optical converters (PICOC's) because of their dynamic real-time grating recording properties.'5 In a general PICOC, the imagebearing incoherent light is used to erase the grating, which is constructed by two coherent writing beams. The output image is carried by the diffracte...

Image Enhancement in Coherent Optical Amplification by Photorefractive Crystals

In this paper, a model of two-wave mixing in the photorefractive crystal, which takes account of the difference in spatial frequency in a beam, has been built to study the image enhancement effect in coherent optical amplification. Based on the theoretical analysis of the model, the gain distribution for each pixel in the signal beam has been obtained. It shows that the unevenness of the gain i...

Coherent and Incoherent Crosstalk in WDM Optical Networks

The impact of coherent and incoherent crosstalk on an optical signal passing through optical cross-connect nodes (OXC’s) in wavelength division multiplexing (WDM) optical networks is studied, and the analytical expressions are given. Such crosstalk will be generated when the optical propagation delay differences of optical paths in an OXC do not exceed the coherent time of the lasers. While cau...