Pulse synthesis in the single-cycle regime from independent mode-locked lasers using attosecond-precision feedback

Abstract

We report the synthesis of a nearly single-cycle (3.7 fs), ultrafast optical pulse train at 78 MHz from the coherent combination of a passively mode-locked Ti:sapphire laser (6 fs pulses) and a fiber supercontinuum (1-1.4 μm, with 8 fs pulses). The coherent combination is achieved via orthogonal, attosecond-precision synchronization of both pulse envelope timing and carrier envelope phase using balanced optical cross-correlation and balanced homodyne detection, respectively. The resulting pulse envelope, which is only 1.1 optical cycles in duration, is retrieved with two-dimensional spectral shearing interferometry (2DSI). To our knowledge, this work represents the first stable synthesis of few-cycle pulses from independent laser sources.

Recent advances in ultrafast optical parametric oscillator frequency combs

“…Synthesis has also been demonstrated between lasers with different gain media, including Ti:sapphire and Cr:forsterite lasers, [20][21][22] and a Ti:sapphire and an erbium-doped fiber laser. 23 CEP stabilized OPOs 24 present a unique vehicle for synthesizing coherent waveforms across wide bandwidths, far exceeding those available from laser gain media. 25 In previous work carried out within the authors' group, *Address all correspondence to: Richard A. McCracken, E-mail: r.a.mccracken@ hw.ac.uk a Ti:sapphire-pumped synchronous OPO based on a cascaded-grating MgO:PPLN crystal was used to demonstrate pulse synthesis between the depleted pump pulses and intracavity-doubled-signal pulses from the OPO.…”

All-optical control of unipolar pulse generation in a resonant medium with nonlinear field coupling

“…All these applications turn to be highly sensitive to the maximal flexibility in the ultrashort pulse profiling. Today's research mainstream in the generation of ultrabroadband pulses develops towards the subcycle waveform synthesis that is the coherent combination of pulses generated from different sources covering separate spectral regions [20,22,[40][41][42][43][44]. The synthesis of ultrashort pulses calls for careful manipulation of the parameters of the individual pulses, namely the spec-tral phase, carrier phase and the relative delay between the sources.…”

Mode Profile Shaping in Wire Media: Towards An Experimental Verification

“…The idea has been implemented by means of harmonic synthesis [4,5], and suggested in the context of nonlinearity-induced carrier shocking [6][7][8]. Such shaped waveforms have been suggested as a means of enhancing ionisation in high harmonic generation [9,10].…”