Weak‐Field, Multiple‐Cycle Carrier Envelope Phase Effects in Laser Excitation

Abstract

Although the absolute or carrier envelope phase (CEP) of a laser pulse is usually assumed to be effective for ultrashort and/or ultrastrong pulses only, it is demonstrated that these limitations can eventually be removed. Therefore, the excitation of a model positively charged homonuclear diatomic molecule, in which four electronic states are coupled by the laser field, is studied. In an initial step, nuclear wave packets in two dissociative states are prepared. Upon reaching the fragment channel, a weak pulse interacts with the system and prepares CEP-dependent asymmetries associated with electron density localized on one or the other fragmentation product.

Phase-only laser control in the weak-field limit: Two-pulse control of IBr photofragmentation revisited

“…It has even been shown in model studies that the carrier envelope phase, φ(ω) = φ 0 , of the second (multi-cycle) pulse can play a role. 19,20 Since the first pulse can create a nonstationary superposition of eigenstates, the original seminal work of Brumer and Shapiro 21 suggests that a general phase modulation of the second pulse will allow for the manipulation of quantum mechanical interference terms.…”

Carrier-envelope-phase-dependent above-threshold ionization of xenon observed with multi-cycle laser pulses

“…Even the CEP of few-cycle laser pulses can be determined by these methods, it is still a meaningful question to ask the maximum pulse duration to observe the CEP effect and how to extract the absolute phase from multi-cycle pulses. The CEP of a femtosecond pulse could be a control parameter in investigating electronic transition processes in molecules coupled with multi-cycle laser [20] or molecular dynamics [21]. Photo-fragmentation, for example, was demonstrated for heavy molecules with CEP-controlled laser pulses [22].…”

Coherent and incoherent contributions to the carrier-envelope phase control of wave packet localization in quantum double wells

“…28 Opposite to that we have shown in our recent work that this limitations can be removed and that the influence of the absolute phase on the asymmetry of fragment distributions in a molecular A + 2 -dissociation exists also in the case of weak and multicycle excitation pulses. 29 In another example, the dynamics in a double-well potential as is displayed in Fig. 1 was studied.…”