Increased phase-matching bandwidth in simple ultrashort-laser-pulse measurements

摘要

Recently we introduced an extremely simple device for measuring ultrashort laser pulses, which utilizes a thick nonlinear-optical crystal, that replaces the usual thin nonlinear-optical medium and spectrometer simultaneously. It also replaces the usual beamsplitter and delay line with a single optic, a Fresnel biprism, which requires no alignment. Here we review the operation of the device and show that dithering the lateral position of the input beam in such a device increases the spectral range of the device with no loss in spectral resolution. Furthermore, we show that it separates the two constraints on crystal selection, allowing the measurement of a wider range of spectrally broader and/or more complicated pulses.