PROOF for attosecond pulse characterization

Attosecond pulses are typically characterized using an attosecond streak camera. The amplitude and phase of the attosecond pulse are retrieved from the delay-dependent streaked spectrogram using a technique known as FROG-CRAB (frequency-resolved optical gating for complete reconstruction of attosecond bursts). This method, however, are not appropriate for pulses whose spectral bandwidth is large than the center photon energy. We developed a new technique for characterizing attosecond pulses, whereby the spectral phase of the attosecond pulse is extracted from the oscillation component with the dressing laser frequency in the photoelectron spectrogram. This technique, termed PROOF (Phase Retrieval by Omega Oscillation Filtering), can be applied to characterizing attosecond pulses with ultrabroad bandwidths. The spectral phase encoding in PROOF can be described by quantum interference of the continuum states caused by the dressing laser. We are working on refining the PROOF method for characterizing ultrabroad bandwidth attosecond and zeptosecond pulses.

Michael Chini, Steve Gilbertson, Sabih D. Khan, and Zenghu Chang, “Characterizing ultrabroadband attosecond lasers,” Opt. Express 18, 13006 (2010).