Visible wavelength autocorrelation based on the two-photon absorption in a SiC photodiode and a GaInN light emitting diode

In order to record the autocorrelation signal the SHG signal has usually been measured by a photomultiplier tube (PMT). However, the method requires a precise alignment to achieve critical phase matching in a nonlinear crystal. We will demonstrate the real-time autocorrelation measurement by using the GaInN light emitting diode (LED) and the extended utility of the SiC photodiode in visible wavelength range. We measured the power dependence of the average photocurrent in the SiC photodiode.