Simple technique to retrieve phase and magnitude of weak ultrashort laser pulses using a stronger unknown pulse

To determine the phase and magnitude of the complex electric field of
weak ultra-short pulses we propose to use a dummy strong pulse time
delayed relative to the weak pulse that needs to be characterized. This
whole sequence of two pulses is then sent to an optical spectrum
analyzer, which yields the square of the FT magnitude of the complex
electric field function of the pulse sequence. By simply choosing a strong
pulse time delayed with respect to the weak pulse, the whole pulse
sequence becomes close to a minimum phase function. This makes the
recovery of the full complex electric field of the weak pulse possible from
only the measurement of the FT magnitude of the complex electric field
function of the pulse sequence. The recovery processing conveniently
involves a simple and fast iterative error reduction algorithm, such as the
Fienup algorithm.

This patent is available for licensing through Stanford's exclusive licensee.
Please contact Dennis Fortner at: Dennis.Fortner@ngc.com for licensing information.