Filamentation and discrete supercontinuum generation in dielectric materials

A new method of filamentary discrete lines supercontinuum generation is reported. It is based on distributed feedback dye laser action instead of the conventional propagation of femtosecond pulses through open air or photonic molecules. Novelty of the technique, ease and economy make it attractive for continual spectral lines generation. Although, this work was carried out by pumping dye solution with only six pulses to generate 45 nm wide supercontinuum, consisting of nine distinct coherent lines, but the principle may be extended to any desired spectral range, depending upon the available gain medium and number of pumping pulses. Successful design and operation of multi-wavelength laser source, an off white supercontinuum, using a mode-locked and frequency doubled picosecond Nd:YAG laser is presented to demonstrate filamentation in atmosphere.