Time-resolved coherent polarimetry using polarization vortices

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13369
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Optical engineering, Photon science
• Research Institution: Hokkaido University
• Principal Investigator: Toda Yasunori 北海道大学, 工学研究院, 教授 (00313106)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 光物性 / 偏光渦 / 縮退四光波混合

Outline of Final Research Achievements

We have developed a novel type of coherent spectroscopy (time-resolved polarimetry using nonlinear laser spectroscopy known as degenerate four-wave-mixing) using polarization vortices characterized by a vector singularity on the beam cross-section, and performed the spectroscopy on semiconductor GaN excitons (electron-hole pairs). We successfully obtained the results concerned as follows: (a) quantitative snap-shot evaluations of exciton spin exchange and uniaxial strain energies; especially for small residual anisotropies in isotropic samples; (b) coherent dynamics of the polarization singularities resulting from broken rotational symmetries of excitons, (c) spin and pseudo-spin dynamics and their correlations resulting from excitons interactions.

Free Research Field

光物性