Cyrus D. Cantrell

Resonance structure of multiple-photon excitation in symmetric and asymmetric tops☆

Abstract IR multiphoton resonances have been observed in the absorption spectra of C 2 F 5 Cl, CF 3 Br and CF 3 I excited by means of a continuously-tunable CO 2 laser. Their preliminary assignment, based on available spectroscopic data, shows the relevance of hot bands and Fermi resonances in the first steps of the non-linear laser excitation. The significance of multiphoton resonances for laser chemistry and isotope separation is discussed briefly.

Solution of the schrödinger equation for systems driven by an exponential or a semiexponential pulse

Abstract The time-dependent probability amplitudes of a general multilevel system can be obtained analytically as power series in the pulse area for quasimonochromatic pulses with special envelope shapes in the rotating-wave approximation. Closed-form solutions can also be found for some cases of interest. These solutions are useful in evaluating the correctness of the adiabatic approximation and in illustrating the dependence of the intramolecular relaxation time on the conditions of excitation.

Study of multiphoton resonances in the CF3I molecule

Abstract A systematic investigation of the MPA and MPD of CF 3 I by CO 2 laser radiation has been performed under collision-free conditions. Prominent structures observed in MPA spectra have been identified as vibration—rotation multiphoton resonances on the basis of their dependence on laser frequency and fluence and the gas temperature. Narrowing of the thermal rotational distribution was also accomplished by cooling the CF 3 I in a molecular beam in order to study the purely vibrational compensation of anharmonicity.

Nonperturbative quantum calculation of the index of refraction of multilevel systems

Abstract We calculate the index of refraction ( n ) nonperturbatively for a multilevel ladder of states, and show that the dependence of n on the strength of an applied laser field departs qualitatively from that expected for a two-level system and employed in previous phenomenological models of self-focusing.