Parallel Microstructuring using Femtosecond Laser and Spatial Light Modulator

AbstractThe spatial light modulator together with the computer generated holograms can be used to shape laser beam to correspond for specific need of the micromachining task. Especially dividing the original laser energy to beam array enables high degree of parallelism in laser micromachining. Spatial light modulator together with femtosecond laser enables fast machining of the complex structures with feature sizes down to a few microns

Spreading properties of beams radiated by partially coherent Schell-model sources

We derive a general law for the M-2 factor of any beam generated by a partially coherent Schell-model source. The fourth power of M differs from its minimum value, attained in the coherent limit, by a term proportional to the second derivative of the modulus of the spectral degree of coherence evaluated for zero argument. Examples are given for cases of practical interest. (C) 1999 Optical Society of America [S0740-3232(99)01501-X]

Spreading properties of beams radiated by partially coherent Schell-model sources

We derive a general law for the M-2 factor of any beam generated by a partially coherent Schell-model source. The fourth power of M differs from its minimum value, attained in the coherent limit, by a term proportional to the second derivative of the modulus of the spectral degree of coherence evaluated for zero argument. Examples are given for cases of practical interest

Strong enhancement of second-harmonic generation in all-dielectric resonant waveguide grating

The authors demonstrate that a dielectric resonant waveguide grating can enhance optical second-harmonic generation by a factor of 550 compared to a similar flat surface. Their structure, which consists of purely dielectric and thereby transparent materials, has a low index silicon dioxide grating covered by a high index titanium dioxide layer and it is optimized for the fundamental wavelength of 1064 nm. Polarization dependence of the second-harmonic response suggests that the enhancement arises from the favorable interaction of the resonant waveguide mode and its strong local field with the inherent surface nonlinearity of the dielectric materials.Peer reviewe

Giant enhancement of second-harmonic generation in multiple diffraction orders from sub-wavelength resonant waveguide grating

We demonstrate a purely dielectric resonant waveguide structure that enhances the efficiency of second-harmonic generation by a factor of at least 5500 compared to a flat reference surface in the same geometry. We also show that the structure emits second-harmonic radiation in four different directions when the sample is illuminated with fundamental radiation incident at the resonant angle of the sample.Peer reviewe