Phase Measurement Methods for Femtosecond Pulses.

Spatial phase dislocations in femtosecond laser pulses

We show that spatial phase dislocations can be generated in femtosecond laser beams by computergenerated holograms provided they are build in a setup compensating for the introduced spatial dispersion of the broad spectrum. We present analytical results describing two possible arrangements dispersionless 4f -setup and double-pass grating compressor. Experimental results on the generation of opt...

Light-emitting diodes as measurement devices for femtosecond laser pulses.

We present results showing that, when it is used as a photodetector, a light-emitting diode (LED) has a power-dependent response that can be used for sensitive detection and characterization of picosecond and femtosecond laser pulses. A characterization of a typical LED is presented at 800 nm, and we demonstrate how this effect can be used to construct an extremely compact novel autocorrelator ...

Femtosecond Laser Pulses: Linear Properties, Manipulation, Generation and Measurement

Long distance measurement with femtosecond pulses using a dispersive interferometer.

We experimentally demonstrate long distance measurements with a femtosecond frequency comb laser using dispersive interferometry. The distance is derived from the unwrapped spectral phase of the dispersed interferometer output and the repetition frequency of the laser. For an interferometer length of 50 m this approach has been compared to an independent phase counting laser interferometer. The...

Direct measurement of spectral phase for ultrashort laser pulses.

We present an intuitive pulse characterization method that provides an accurate and direct measurement of the spectral phase of ultrashort laser pulses. The method requires the successive imposition of a set of quadratic spectral phase functions on the pulses while recording the corresponding nonlinear spectra. The second-derivative of the unknown spectral phase can be directly visualized and e...