A fiber optic spectrometer produced by a femtosecond, 400-nm second harmonic Ti:Sapphire laser

A second harmonic 400-nm femtosecond pulse laser has demonstrated efficient hole drilling for a fiber optic spectroscopic measurement. A pulse train of 1 kHz with a pulse width of 350 fs was irradiated during approximately 1 s onto an optical fiber to make a through hole that penetrates whole fiber core and works to be a sample cell for a spectroscopic measurement. The spectroscopic measurement is shown using dye of rhodamine 6G. Even with a pico-liter cell volume of a through hole, the absorption spectrum is appeared in the visible range centered at 530 nm depending on the dye concentration. Discussions have also been made on the optimum arrangement of the through hole to obtain sufficient performance of spectroscopic measurements.