Coherent and phase-sensitive phenomena of ultrashort laser pulses propagating in three-level {lambda}-type systems studied with the finite-difference time-domain method
- Departament de Fisica i Enginyeria Nuclear, Universitat Politecnica de Catalunya, Colom 11, 08222 Terrassa (Spain)
Propagation of single- and two-color hyperbolic secant femtosecond laser pulses in a three-level {lambda}-type quantum system is investigated by solving the Maxwell and density matrix equations with the finite-difference time-domain and Runge-Kutta methods. As a first study of our modeling, we simulate pulse self-induced transparency (SIT) in two-level systems and see how this phenomenon can be controlled by manipulating the initial relative phase between the SIT pulse and a second control pulse, provided the ratio between both pulse frequencies obeys the relation {omega}{sub 1}/{omega}{sub 2}=3. We then examine frequency down-conversion processes that are observed with single- and two-color pulses the envelope area of which is equal to or a multiple of 2{pi}, for pulse frequencies close to resonance with the transitions of a three-level {lambda} medium. Also, phase-sensitive phenomena are discussed in the case of two-color {omega}-3{omega} pulses propagating resonantly in the three-level system. In particular, possibilities for such coherent control are found for frequency down-conversion processes when the ratio of the frequencies of optical transitions is {omega}{sub 13}/{omega}{sub 12}=3. The conditions for quantum control of four-wave mixing processes are also examined when the pulse frequencies of two-color {omega}-3{omega} pulses are far from any resonance of the three-level system. We demonstrate the possibility to cancel the phase sensitivity of the four-wave coupling in a {lambda}-type system by competition effects between optical transitions.
- OSTI ID:
- 20787574
- Journal Information:
- Physical Review. A, Vol. 73, Issue 6; Other Information: DOI: 10.1103/PhysRevA.73.063809; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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