Measurement of Carrier-Envelope-Phase shifts using spectral interferometry with a broad frequency laser source

We investigate and analyze in detail an approach to measure Carrier Envelope Phase shifts by using spectral interferometry. The method which uses a broadband laser source is applied to the characterization of an Electro Optic Carrier Envelope Phase shifter and leads to quick and accurate measurements on a large frequency domain. The shifter is inserted in one arm of a Mach–Zehnder interferometer illuminated by a wide frequency spectrum coherent source. By carefully analyzing the observed fringes, we successfully derived, with a very good accuracy, the main useful parameters of the CEP shifter on the whole investigated wavelength spectrum. The laser source which delivers pulses with a Gaussian spatial distribution and a nearly flat spatial phase does not need to be CEP stabilized and no control of the spectral phase of the pulses is necessary. This has specific advantages compared to other methods.