Ultrafast laser nanostructuring of glass: from S-waveplate to multidimensional data storage

Material processing with ultrafast lasers has attracted considerable interest due to new science and a wide range of applications from laser surgery, integrated optics to optical data storage. A decade ago it has been discovered that under certain irradiation conditions ordered sub-wavelength structures with features smaller than 20 nm can be formed in the volume of silica glass. Here we discuss recent applications of self-assembled sub-wavelength structuring specifically polarization converters branded as the S-waveplate and polarization multiplexed optical data storage

Patterned birefringent polarization converters fabricated by femtosecond laser direct writing

Under certain exposure conditions, focused femtosecond light pulses can induce self-assembled nanogratings inside bulk of fused silica glass. Orientation of nanogratings is always perpendicular to incident light polarization. Induced nanograting period varies from 140 nm to 320 nm. By changing incident light power and polarization orientation we can control induced retardance and slow axis of fabricated birefringent patterns. Induced nanogratings exhibit birefringence that provide retardance as large as 260 nm, which is sufficient for performing the required polarization conversion at visible and near-infrared wavelengths. Recently radially polarized optical vortex converter, Fresnel zone plates, polarization diffractive gratings, radial or azimuthal polarization converters were fabricated by inducing nanogratings in fused silica bulk

Applications of ultrafast laser direct writing: from polarization control to data storage

Ultrafast laser direct writing is a fascinating technology which emerged more than two decades from fundamental studies of material resistance to high-intensity optical fields. Its development saw the discovery of many puzzling phenomena and demonstration of useful applications. Today, ultrafast laser writing is seen as a technology with great potential and is rapidly entering the industrial environment. Whereas, less than 10 years ago, ultrafast lasers were still confined within the research labs. This talk will overview some of the unique features of ultrafast lasers and give examples of its applications in optical data storage, polarization control and optical fibers.</p

Some numerical problems in differential equations

SIGLEAvailable from British Library Document Supply Centre- DSC:D36459/81 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Signatures of light-beam spatial filtering in a three-dimensional photonic crystal

We report experimental evidence of spatial filtering of light beams by three-dimensional, low-refraction-index-contrast photonic crystals. The photonic crystals were fabricated in a glass bulk, where the refraction index has been periodically modulated using tightly focused femtosecond laser pulses. We observe filtered areas in the angular distributions of the transmitted radiation, and we interpret the observations by theoretical and numerical study of light propagation in index-modulated material in paraxial model.Peer Reviewe