The Department of Physics and Astronomy and the SPIE student chapter invites all to a colloquium featuring Dr. Marija Strojnik Scholl of the Optical Research Center, Infrared Group, Leon, Gto., Mexico. Dr. Scholl will present her talk, “Vision System for Bi-Spectral Simultaneous Monitoring of Dynamic Phenomena at 2000 fps in Infrared”, Tuesday, Nov. 10 at 4:10 pm in Webster B17.
Meet for refreshments before the lecture at 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract: Optical instruments are built to expand the capabilities of the human visual system. The smallest detail that an unaided eye may resolve is 1 arc minute (0.3 mm at 1 m distance). We use a microscope to see smaller details and a telescope or a magnifying glass to make objects appear closer. Human visual system is sensitive only in the spectral region between 0.38 micron and 0.78 micron. However, we are interested in exploring our environment in many other spectral intervals, in particular in infrared (beyond 0.76 microns). Currently, near MegaPixel arrays are employed for advanced diagnosis. Human visual system is also quite slow, the feature that facilitated development of moving pictures. At 60 frames per second (fps), human observers perceive continuous motion. When phenomena occur more rapidly, a human detects a blurred image that his brain cannot interpret. Wild fires, or more generally, combustion is one natural phenomenon that human brain is not capable of analyzing due to the rapidity of its evolution.
For the last 10 years we have been developing instruments to study initiation and propagation of rapidly evolving processes in IR and visible. Here we describe an IR optical experimental setup to capture two images of the same scene, side-by-side on a single detector array. With this arrangement, we observe rapidly changing phenomena, at a rate of more than 1000 frames per second, without loss of the spatial information about the test object. We apply this technique to flame analysis in the mid-IR to determine the combustion efficiency, as measured by the CO-gas production. We observe interesting oscillatory behavior of combustion by-products.
