We present cross-correlation frequency-resolved optical gating (XFROG) measurements of supercontinuum pulses generated by using a photonic crystal fiber (PCF), and ultraviolet (UV) pulses generated by frequency doubling of infrared ultra-short pulses. Since supercontinuum pulses have broad spectra, XFROG measurement typically requires using an extremely thin nonlinear crystal which has a thickness of sub-ten microns. Instead of using such a thin crystal, we employed a relatively thick crystal which was mounted on a galvanometer in order to achieve a phase-matching over the whole spectral bandwidth of the supercontinuum pulses by a crystal-dithering technique. Experimental results of the retrieved phase and intensity were in fair agreement with the independently measured data.
Two different pump-probe (PP) setups were developed successfully with different femtosecond pulse lasers. Using a PP setup with an ultra-short pulse laser, the excitation of coherent phonons in GaAs was measured for a calibration and an accuracy test of the developed setup. The frequencies of the coherent phonon modes were in good agreement with reported values [1, 2]. The setups for ZnSe and GaAs were transmission and reflection–type, respectively. When using the ultra-short pulse laser, the signal in the PP experiment was measured by a balanced photo diode.In the other PP experimental setup, built to measure the transient transmittance of bulk ZnSe, the light source and detector differed from the previous PP setup. A strong pulse laser was successfully used for the spectrally resolved pump probe experimental setup. A broadband, high-resolution spectrometer (HR4000CG-UV-NIR) was used as the detector.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.