Ian Walmsley

Abstract:

We discuss recent developments in the characterization of ultrashort optical pulses in the space-time domain and the attosecond regime. These methods may be applied to the study of the dynamics of the field in nonlinear interactions.

Abstract:

We have measured the joint Q-function of a highly multimode field using unbalanced heterodyne detection with a charge-coupled device array detector. We use spectral interferometry between a weak signal field and a strong, 100 fs duration local oscillator pulse to reconstruct the joint quadrature amplitude statistics of about 25 temporal modes. By adjusting the time delay between the signal and local oscillator pulses we are able to shift all the classical noise to modes distinct from the signal. This obviates the need to use a balanced detector.

Abstract:

We study and demonstrate a version of spectral phase interferometry for direct electric-field reconstruction (SPIDER) that uses self-referencing homodyne detection. This technique has a higher sensitivity than conventional SPIDER, is self-calibrating, and can be adjusted for a wider range of pulse parameters.