Abstract

We have built a compact broad-band femtosecond spectrometer based on a probe light supercontinuum generated in a birefringent photonic crystal fiber (PCF). These micro-structured material systems can be tailored for very efficient generation of broadband "white-light" continua using only moderate laser pulse energies derived e.g. from a Titane-Saphire oscillator, rather than from an expensive multi-component amplified laser chain [1,2], Previous spectrometers of that kind where however limited to wavelengths > 550 nm [1,2] or used 800 nm for excitation [1], The use of multi-channel detection with a CCD operated at 600 Hz read-out rate provides more precise spectral information, and a high signal-to-noise ratio. The ultrafast photo-isomerisation of Malachite Green (MG) excited in S₂ at 430 mn, is presented as a proof-of-principle experiment.

© 2007 IEEE