Kriti Batra

Asymmetric effects on the optical properties of double-quantum well systems

Abstract. Linear, nonlinear, and total absorption coefficient and refractive index changes of double-quantum well (DQW) systems are studied theoretically in the presence of external static electric field applied along the growth direction. The analytical expression for the linear and nonlinear optical properties is obtained using density matrix method. Emphasis is laid on the effect of asymmetry in the shapes of DQW system on optical properties. Some interesting results are obtained and explained.

Multiphoton ionization of atoms using the pseudostate summation technique

An accurate and powerful pseudostate summation technique has been used to study multiphoton ionization of an atom. Results are obtained for three-photon ionization of hydrogen from the ground state, as well as from the metastable 2s state. We calculate the ionization cross section from these states for both linearly and circularly polarized light, thereby showing the effect of polarization of incident photons on the ionization cross section. Although our method of calculation is entirely different, the results mirror closely those obtained by conventional methods.

Atom in a femtosecond bichromatic laser field

The ionization of real hydrogen atom is studied under the action of a two-color pulsed laser field of duration 2.12 fs consisting of a fundamental frequencyω and one of its harmonics. We study the effect of phase difference (φ betweenω and its harmonic on the ionization probability. It is found that ionization can be switched on and off by varying the relative phaseφ betweenω and its harmonic.