Energy efficient method for two-photon population transfer with near-resonant chirped pulses

Abstract

We investigate a method for complete population inversion in three level systems through pi-pulse bichromatic two-photon coherent excitation and study the dependence on the chirp of the laser pulses. We observe that the population inversion does not monotonously decrease with increasing the time-bandwidth product, and that the excitation depends on the sign of the chirp of the individual pulses. Our results evidence a strategy for coherent population transfer which is energetically superior to adiabatic methods and opens the door for real-world applications, since it alleviates the need for challenging generation of transform-limited pulses at arbitrary wavelengths.

Solvent Environment Revealed by Positively Chirped Pulses

“…The viscosities of ethylene glycol at 5, 20, and 50 °C are 45.4, 19.3, and 6.55 mPa s, respectively . Most importantly, our findings reveal that negative chirp, where historically most of the scientific research has focused, ,,,,− is insensitive to solvent viscosity. Negative chirp experiments can be thought of as being similar to pump–probe measurements, in which the bluer wavelength pump precedes the redder wavelength probe.…”

Chirp-dependent dual light emission in Na0.95Er0.05Nb0.9Ti0.1O3 perovskite

“…In order to qualitatively explain the fluorescence results shown in Figure 11 a), we can accommodate the sequential resonance model, previously used by other authors, [44][45][46] to a stationary three-level model for the erbium ion shown in Figure 12 a). Unlike other models, which take into account the femtosecond vibrational wave-packet dynamics, [40,47,48] in the current case, the pulse duration is sufficiently short to assume that the nuclear configuration is approximately frozen during the impulsive excitation.…”

Control of rubidium low-lying Rydberg states with trichromatic femtosecond π pulses for ultrafast quantum information processing

“…For ultrafast control, π-pulse polychromatic control techniques benefit from the fact that no delay between pulses is involved as compared to adiabatic schemes, so that the interaction time remains of the order of the laser pulse temporal width. The control of population transfer between a pair of quantum states involving single or polychromatic transitions by illuminating the atom with resonant π-pulses has extensively been implemented using from long to ultrashort pulses [32,37,38]. For the case of a four-level ladder system, population transfer schemes combining adiabatic and π-pulse techniques have also been proposed [39].…”