TY - JOUR

T1 - Complete elimination of nonlinear light-matter interactions with broadband ultrafast laser pulses

AU - Shu, Chuan-Cun

AU - Dong, Daoyi

AU - Petersen, Ian R.

AU - Henriksen, Niels Engholm

PY - 2017

Y1 - 2017

N2 - The absorption of a single photon that excites a quantum system from a low to a high energy level is an elementary process of light-matter interaction, and a route towards realizing pure single-photon absorption has both fundamental and practical implications in quantum technology. Due to nonlinear optical effects, however, the probability of pure single-photon absorption is usually very low, which is particularly pertinent in the case of strong ultrafast laser pulses with broad bandwidth. Here we demonstrate theoretically a counterintuitive coherent single-photon absorption scheme by eliminating nonlinear interactions of ultrafast laser pulses with quantum systems. That is, a completely linear response of the system with respect to the spectral energy density of the incident light at the transition frequency can be obtained for all transition probabilities between 0 and 100% in multilevel quantum systems. To that end, a multiobjective optimization algorithm is developed to find an optimal spectral phase of an ultrafast laser pulse, which is capable of eliminating all possible nonlinear optical responses while maximizing the probability of single-photon absorption between quantum states. This work not only deepens our understanding of light-matter interactions, but also offers a way to study photophysical and photochemical processes in the "absence" of nonlinear optical effects.

AB - The absorption of a single photon that excites a quantum system from a low to a high energy level is an elementary process of light-matter interaction, and a route towards realizing pure single-photon absorption has both fundamental and practical implications in quantum technology. Due to nonlinear optical effects, however, the probability of pure single-photon absorption is usually very low, which is particularly pertinent in the case of strong ultrafast laser pulses with broad bandwidth. Here we demonstrate theoretically a counterintuitive coherent single-photon absorption scheme by eliminating nonlinear interactions of ultrafast laser pulses with quantum systems. That is, a completely linear response of the system with respect to the spectral energy density of the incident light at the transition frequency can be obtained for all transition probabilities between 0 and 100% in multilevel quantum systems. To that end, a multiobjective optimization algorithm is developed to find an optimal spectral phase of an ultrafast laser pulse, which is capable of eliminating all possible nonlinear optical responses while maximizing the probability of single-photon absorption between quantum states. This work not only deepens our understanding of light-matter interactions, but also offers a way to study photophysical and photochemical processes in the "absence" of nonlinear optical effects.

U2 - 10.1103/PhysRevA.95.033809

DO - 10.1103/PhysRevA.95.033809

M3 - Journal article

SN - 2469-9926

VL - 95

JO - Physical Review A (Atomic, Molecular and Optical Physics)

JF - Physical Review A (Atomic, Molecular and Optical Physics)

IS - 3

M1 - 033809

ER -