Broad and tunable second harmonic generation from 250 to 430 nm from a 80 MHz picosecond white light source

摘要: Supercontinuum generation in microstructured fibers is a most versatile method to generate wide range of visible near infrared colors from fixed wavelength femto- and picosecond sources. Since photonic crystal structures lead favorable zero-dispersion close the pump wavelength, high fiber lengths can be used. As consequence, nJ pulse energies out MHz repetition rate oscillators are sufficient for spectral broadening. So far, however, shortest wavelengths that readily achieved just slightly below 400 nm. For many applications biology chemistry, e.g., fluorescence lifetime imaging (FLIM), total internal reflection (TIRF) microscopy or single molecule imaging, light UV - as far down 250 nm DNA bases needed. No either laboratory commercial "white lasers" (WLL), i.e. combination ps laser with fiber, has been reported.