Xianjun Ke

Holographic storage in carbazole-azo binary compound doped polymer

Abstract A series of novel materials of carbazole-azo binary compound doped polymer were introduced for holographic storage. Optical absorption changes orientation distribution of trans isomer of azobenzene moiety that results in the modulation of the refractive indices of azo doped polymer film without additional pump light. The diffraction efficiency of the 15 μm thick film of 4′-carbazolylhexoxyl-2-methyl-4-nitro azobenzene is about 0.65%.

All-optical controlled variable optical attenuator using photochromic sol gel material

In this letter, we report an all-optical controlled polarization-dependent variable optical attenuator using a photochromic sol gel material developed by us. Optical attenuation is achieved by means of photochromic phase modulation in a Mach-Zehnder interferometric waveguide device fabricated with the sol gel film. A 5-mW/mm/sup 2/ light illumination at 532 nm on a 3-mm-long sol gel arm was found to produce a complete 2/spl pi/ phase shift between the two arms of the device, resulting in a 15-dB attenuation dynamic range for transverse-electric-polarization light. The response time of the device is around 50 ms. The wavelength-dependent performance of the device has been characterized across the entire C-band.

Dye-doped polymer film for holographic storage

A new dye-doped polymer film has been developed and typical optical storage properties are assessed using green CW and nano-second pulse lasers. Initial results indicate a large film refraction index modulation in the third decimal under light exposure, suggesting the film as potential medium for high-density holographic data storage applications.

2 × 2 grating assisted all-optical waveguide switch

2 × 2 grating assisted all-optical waveguide switch is realized on ion-exchanged channel waveguides with a new dye-doped sol-gel cover film. The switching state is controlled by the photo-induced dynamic generation of gratings in the sol-gel film. Switch characteristics such as crosstalk, speed, and on-off ratio will be reported.