TANAKA LAB. Physics of Soft Condensed Matter The University of Tokyo Graduate School of Engineering Department of Applied Physics The University of Tokyo Institute of Industrial Science Department of Fundamental Engineering
Entrance > Research > Light and Soft Matter > Phase-Coherent Light Scattering Method
Polymer, Liquid Crystal, Colloid, Membrane, ProteinLiquid, Glass, GelLight and Soft Matter
Phase-Coherent Light Scattering MethodOptical ManipulationTime Resolved Simultaneous Observation of Polarized and Depolarized Small Angle Light Scatteing2D Dynamic Fourier Transform Infrared Spectroscopy

Phase-Coherent Light Scattering Method

Phase-Coherent Light Scattering Method We demonstrate here a new phase-coherent light scattering method. Spontaneous Brillouin scattering is caused by thermally excited phonons whose phases have no physical meaning because of their random, incoherent nature. However, coherent phonons having phase information can be generated resonantly by an optically induced scanning interference pattern, when the dispersion relation of phonons is satisfied. By a phase-sensitive detection of the light scattered by optically generated coherent phonons, we have succeeded in measuring complex resonance spectra of acoustic phonons, which we call complex Brillouin spectra, with an ultimate signal-to-noise ratio.