ACT Branch
The June 2010 Meeting
Continuing are series of talks marking the 50th anniversary of the laser,
Dynamic microscopy: From optical micro-manipulation to neuronstimulation
| Speaker | Dr Vincent Daria
Research School of Physics and Engineering and the John Curtin School of Medical Research, The Australian National University |
| Time | Wednesday 23rd of June 2010 6.00pm (refreshments available from 5.30pm) |
| Location | Research School of Physics and Engineering Seminar Room Cockroft/Oliphant Link Building, Australian National University Building 58D on the campus map |
In this talk, I will summarize techniques for generating programmable three-dimensional (3D) optical field patterns as used in multi-beam micro-manipulation of mesoscopic particles. I will discuss three techniques for array illumination based on: (1) high-speed beam scanning (2) Holographic projection and (3) the Generalized Phase contrast method. I will show experiments demonstrating effective transfer of linear, spin and orbital angular momentum on dielectric and birefringent particles and point to potential biological applications. Then I will discuss uses of these complex optical field patterns for non-linear energy transfer via multi-photon absorption for laser surgery, photopolymerization and photostimulation. Towards the end, I will show recent experiments in neuroscience where 3D optical field patterns are used for simultaneous multi-site photostimulation of neurotransmitters and recording of neuronal activity.
Dr. Daria earned his PhD in Applied Physics from Osaka University (Japan, 2000), where he developed a two-photon microscope and analyzed fs-laser light propagation in turbid medium for studying the growth of mouse embryos. From 2001-04, he has been a Scientist at the Risoe National Laboratory(Denmark), where he worked with spatial light modulators (SLM) to produce multi-beam optical tweezers for manipulating microscopic objects and cells. Their work on optical tweezers was in Denmark's top five most promising technical innovations of 2004.From 2004-07, he took up a teaching position at the University of the Philippines and established a group to work on ultrafast lasers in combination with SLM technology for trapping, non-linear processes and fs-laser nanosurgery of cells. In 2007, he joined the Australian National University to set up a SLM-based multi-photon microscope for applications in neuroscience.