[18a-Z06-1~11] 3.6 Ultrashort-pulse and high-intensity lasers

▲ [18a-Z06-3] Attempt to form a gaseous crystal with macroscopic three-fold symmetry

〇Tong Ke¹, Mirai Fukase¹, Shinichirou Minemoto¹, Hirofumi Sakai¹ (1.Univ. Tokyo)

Keywords:threefold symmetry, molecular orientation, ion imaging

By generating a three-fold symmetric electric field formed by the superposition of counterrotating circularly polarized lights of two wavelengths (fundamental wave and its second harmonic), it is possible to align sample molecules with threefold symmetry such as BCl3 with their three arms along (or in between) the laser electric fields with threefold symmetry. Therefore, it is expected to form a molecular ensemble with macroscopic three-fold symmetry (a gaseous crystal with three-fold symmetry). We developed an ion imaging spectrometer which observes the angular distributions of fragment ions within the polarization plane of circularly-polarized laser pulses in order to investigate the state of "the molecular ensemble with threefold symmetry". The spectrometer projects the angular distributions of fragment ions within the polarization plane onto the two-dimensional detector plane by applying a pulsed high voltage perpendicular to the TOF axis at an appropriate timing. The operation of the spectrometer has been checked by OCS molecules as sample molecules.