Event Details

Optics News

Capturing Water Splitting by Photosystem II Using a Femtosecond Laser

Speaker: Chris Vincent

A 3-D image of the PSII protein complex, used in photosynthesis, splitting water has been created by researchers using an X-ray free electron laser. The understanding of this reaction sheds new light on the process of photosynthesis and could lead to the development artificial photosynthesis which, in turn, could be used to develop new cleaner energy sources.

Main Talk

Synthesizing and Shaping Ultrafast Pulses Effectively Using Coherently Generated Raman Sidebands

Speaker: Chris Marble

In 2014 the American National Standards Institute laser safety standard ANSI Z136.1-2014 was updated to include new experimental data that determined the threshold for damage to eye tissues from nanosecond laser pulses. As part of this revision, the maximum permissible near-infrared intensity was greatly increased and the results extrapolated to shorter pulse durations. Theoretical and early experimental work suggests that exposure to near-infrared femtosecond laser pulses operated within ANSI limits could result in eye damage due to non-linear effects such as supercontinuum generation. This talk will cover work to numerically simulate the propagation of femtosecond pulses in aqueous media and the human eye. The standard method is to solve the nonlinear Schrodinger equation which is known to be computationally intensive. Dr. Wharmby at the Air Force Research Laboratory (AFRL) has proposed solving a fractional wave equation which is expected to be less computationally intensive to solve than the nonlinear Schrodinger equation. This talk will discuss the fractional calculus used to build the fractional wave equation and ongoing work to numerically solve the fractional wave equation. Future work will include comparing outputs from the fractional wave equation and nonlinear Schrodinger equation and testing these models against experimentally measured propagation of femtosecond pulses in aqueous media and the bio-effects of femtosecond pulses in eye tissues observed by scientists at AFRL.