Beam deflection measurement of bound-electronic and rotational nonlinear refraction in molecular gases

Abstract

A polarization-resolved beam deflection technique is used to separate the bound-electronic and molecular rotational components of nonlinear refractive transients of molecular gases. Coherent rotational revivals from N(2), O(2), and two isotopologues of carbon disulfide (CS(2)), are identified in gaseous mixtures. Dephasing rates, rotational and centrifugal distortion constants of each species are measured. Polarization at the magic angle allows unambiguous measurement of the bound-electronic nonlinear refractive index of air and second hyperpolarizability of CS(2). Agreement between gas and liquid phase second hyperpolarizability measurements is found using the Lorentz-Lorenz local field correction.

Nondegenerate two- and three-photon nonlinearities in semiconductors

“…We apply our recently developed ultrafast beam deflection (BD) technique [19,29,30] to measure the ND-NLR of several direct-gap semiconductors. The experimental setup and beam geometries are shown in Figure 8(a).…”

Dispersion of nondegenerate nonlinear refraction in semiconductors

“…To experimentally measure ND-NLR of semiconductors, we utilize our recently developed beam-deflection technique [35][36][37][38]. BD is an excite-probe technique where we use fs pulses along with a temporal delay line, as shown in Fig.…”

“…BD is a highly sensitive excite-probe technique capable of simultaneously measuring the absolute magnitude, sign, and temporal dynamics of both NLR and NLA. We previously applied BD to measure the nonlinearity of fused silica [35], the response functions of various liquid solvents [36,37] and NLR transients of molecular gases [38]. Here, using very different excitation and probe wavelengths, the dispersion of the ND-NLR is measured over the sub-gap region, along with ND-2PA or nondegenerate threephoton absorption (ND-3PA).…”

Изменение Нормальных Координат И Геометрических Параметров Молекулы В Лазерном Поле

“…Среди достижений последних лет можно указать исследование лазерного химического синтеза [1,2], лазерный контроль движения молекуляр-ных электронов [3,4] и изменения оптических свойств газа когерентно вращающихся молекул [5][6][7][8], спектро-скопию комбинационного [9] и когерентного антисток-сова рассеяния света [10], перегруппировку атомов при лазерной фрагментации молекул [11], наблюдение двухэлектронного отрыва от анионов SF − 6 [12,13] и F − (NF 3 ) n [14]. В недавнем эксперименте [15] была продемонстри-рована важная роль " одетого полем" атома при рас-сеянии на нем электрона в поле лазерного излучения (laser-assisted electron scattering, LAES), теоретически рассмотренного в работе [16].…”