title: 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.
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. joncox@alum.mit.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Cox
authors.forename: W P
authors.initials: WP
authors.lastname: Putnam
authors.forename: A
authors.initials: A
authors.lastname: Sell
authors.forename: A
authors.initials: A
authors.lastname: Leitenstorfer
authors.forename: F X
authors.initials: FX
authors.lastname: Kärtner