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Goddard Space Flight Center, Greenbelt, Maryland 20771

ENGINEERING COLLOQUIUM

Monday, October 19, 2009 / 3:30 PM, Building 3 Auditorium

photo of mantis shrimp

Don Wolpert

"Optical Filters in Nature"

ABSTRACT -- There are interesting parallels between scanning multi-specrtral optical instruments and the eyes of some organisms. It can be difficult to understand how nature fabricates and integrates these systems, but the rewards of such understanding can be great. One of the animals that inspires biomimicking is the mantis shrimp. This talk will discuss the properties of the mantis shrimp and its ability to undertake multi-spectral imaging and polarization detection.

The two compound eyes of this shrimp are mounted on mobile stalks that are independent of one another. The eyes show saccadic movement, that is, a rapid sequence of redirections for targeting of prey. After the prey is targeted, the eyes stabilize the image and slowly track the object.

Each eye has six linear detector rows in the space between the upper and lower hemispheres of the eye. Rows one through four are for color vision. Each of the four rows has eight different visual pigments giving it a visual range from 400 nanometers (nm) to 550 nm. In addition, these rows extend their wavelength range to 650 nm (in almost ten equal spectral intervals), by means of three additional layers containing compounds that tune and shape the light that reaches the visual pigments.

Rows five and six of the central band detect ultraviolet light and polarized light. These rows simultaneously measure four linear and two circular polarization components of the light. The measurement of these polarized components can enhance contrast, a fact known to any microscopist who studies living cells in a liquid medium.

SPEAKER -- H. D. "Don" Wolpert has been interested in bio-optics, bio-mimicking, and bio-inspiration for many years. His numerous papers and talks on these subjects have introduced many people to the benefits of understanding nature's solutions to optics and physics problems.

Don retired from Northrop Grumman Space Technology (formerly TRW) in January 2008 after 45+ years in the aerosopace industry, both commercial and defense. Trained and educated traditionally, he began, early in his career, to use bio-mimicking in his optical engineeering work. Don has extensive experience in the design, fabrication, and testing of sensors in the near, mid, and long infrared, as well as the optical and ultraviolet regions of the spectrum. In this work, he acted as an electro-optical physicist, a systems engineer, and a biologist. He has worked on both room temperature and cooled sensors.

Don has recently worked on the development of single photon area arrays with individual pixel timing resolution from 1 to 0.5 nanosecond for 3-D LADAR imaging. A number of other programs have required working with optical coating houses for the development of advanced optical filters for optical communications, multi-spectral instruments, and solar rejection. He was in charge of the optical telescope system for Kompsat, a Korean oceanographic space payload, and was technically responsible for the opto-mechanical subsystem for Hyperion, a space borne hyper-spectral payload instrument for Goddard Space Flight Center.


Engineering Colloquium home page: https://ecolloq.gsfc.nasa.gov