New ultrashort pulsewidth measurement technology based on interference jitter and FPGA platform

Conventional ultrashort pulsewidth measurement technology is autocorrelation based on second-harmonic generation; however, nonlinear crystals and bulky components are required, which usually leads to the limited wavelength range and the difficult adjustment with free-space light alignment. Here, we proposed a compact all-fiber pulsewidth measurement technology based on the interference jitter (IJ) and field-programmable gate array (FPGA) platform, without requiring a nonlinear optical device (e.g., nonlinear crystal/detector). Such a technology shows a wide measurement waveband from 1 to 2.15 mu m at least, a pulsewidth range from femtoseconds to 100 ps, and a small relative error of 0.15%-3.8%. In particular, a minimum pulse energy of 219 fJ is experimentally detected with an average-power-peak-power product of 1.065 x 10(-6) W-2. The IJ-FPGA technology may offer a new route for miniaturized, user-friendly, and broadband pulsewidth measurement.