Event Details

Practically all ground-based astronomical spectrographs built to date follow the Bunsen-Kirchhoff design, in which a collimator delivers planar wavefronts to a flat diffracting element followed by a camera that forms the spectral image. Curved grating spectrographs, e.g. Offner designs, offer significant advantages over Bunsen-Kirchhoff style devices, but high cost and limited grating size have restricted their application to space astronomy. Over the past two years, Dr. Clemens has led an effort to develop spherically-curved VPH gratings that operate in transmission or reflection and can be recorded at low cost in sizes up to 300mm. In this talk he will describe this new technology and introduce a new family of curved grating spectrograph designs developed in collaboration with Darragh O’Donoghue (SAAO). These designs are simple, compact, highly-efficient, and inexpensive to construct. They will dramatically expand the capabilities of ground-based telescopes. Dr. Clemens will also present the test results from a bench-top prototype spectrograph constructed in the Goodman Laboratory.