Superior Method for Measuring Chirp Structure of Femtosecond Supercontinuum Pulse

We present a straightforward method to measure the temporal chirp structure of supercontinuum (SC) pulses. Wavelength-tunable laser pulses acquired from the chirped SC are spatially separated from the incident SC region, which can be detected with zero background in the detection plane. Experimental results show that this convenient method, which is based on ultrafast transient lens effect, has many advantages compared with ordinary optical Kerr gate method.