Few‐optical‐cycle light pulses with passive carrier‐envelope phase stabilization

Abstract

One of the most advanced frontiers of ultrafast optics is the control of carrier-envelope phase (CEP) φ of light pulses, which enables the generation of optical waveforms with reproducible electric field profile. Such control is important for pulses with few-optical-cycle duration, for which a CEP variation produces a strong change in the waveform, so that strongly nonlinear optical phenomena, such as multiphoton absorption, above-threshold ionization and high-harmonic generation become CEP-dependent. In particular, CEP control is the prerequisite for the production of isolated attosecond pulses. Standard laser systems generate pulses that are CEP unstable; the CEP can be stabilized using either active or passive methods. Passive, all-optical schemes rely on differencefrequency generation (DFG) between two pulses sharing the same CEP: in this process the phases of the two pulses add up with opposite signs, leading to cancellation of the shot-to-shot CEP fluctuations. This paper presents an overview of passive CEP stabilization schemes, starting from the basic concepts and progressing to the details of the practical implementations of the idea. The passive approach allows the generation of CEP-controlled few-optical-cycle pulses covering a very broad range of parameters in terms of carrier frequency (from visible to mid-IR), energy (up to several mJs) and repetition rate (up to hundreds of kHz).

Subfemtosecond steering of hydrocarbon deprotonation through superposition of vibrational modes

“…While in the current proof-of-principle experiment, the degree of control was rather limited, it can be enhanced by using near-single cycle waveforms that are resonant with the optically active mode. With the advent and current development towards the generation of ultrashort, phase-stable light pulses in the mid-infrared 31 , substantial improvement of control is within reach. We expect the control scheme to be widely applicable to a variety of chemical processes, where the reactions of not only asymmetric but also symmetric molecules can be manipulated.…”

Generation of Phase-Stable Sub-Cycle Mid-Infrared Pulses from Filamentation in Nitrogen

“…Following the expression of the CEP in frequency conversion processes described in [49,50], the phase of the generated MIR pulse produced through the process, ω 1 +ω 1 −ω 2 → ω 0 , is given by φ 0 = π/2 + φ 1 + φ 1 − φ 2 , where φ 0 , φ 1 , and φ 2 are the phases of ω 0 , ω 1 , and ω 2 components, respectively. Since ω 2 wave was produced through SH of ω 1 wave, the phase of the ω 2 wave is given by φ 2 = π/2 + 2φ 1 .…”

Temporal Characterization of Front-End for Yb-Based High-Energy Optical Waveform Synthesizers

“…Since the HHG process is driven by the electric field E(t) of an optical pulse, control of the carrierenvelope phase (CEP) is crucial. The CEP can be controlled either actively [2], requiring several feedback loops increasing the system's complexity, or passively, using the difference-frequency process [3][4][5].…”

“…Since the HHG process is driven by the electric field E(t) of an optical pulse, control of the carrierenvelope phase (CEP) is crucial. The CEP can be controlled either actively [2], requiring several feedback loops increasing the system's complexity, or passively, using the difference-frequency process [3][4][5].Previously, we demonstrated passively CEP-stabilized synthesizers pumped by Ti:Sapphire laser technology [3,4], and we have been pursuing average-power scaling with Yb-based pump technology [6,7]. In this particular study, we demonstrate the temporal characterization of a two-channel parametric synthesizer at the µJ energy level, which will serve as the seed source for a mJ-level pulse synthesizer.…”