Richardson Gratings produces large mosaic echelle grating for planet-finder spectrograph

Rochester, NY--A large mosaic echelle grating was manufactured and shipped by Richardson Gratings for use in the Habitable Zone Planet Finder.

Richardson Gratings’ large mosaic echelle grating is shown on a Newport optical workstation. (Image credit:Richardson Gratings)
Richardson Gratings’ large mosaic echelle grating is shown on a Newport optical workstation. (Image credit:Richardson Gratings)

IMAGE: Richardson Gratings’ large mosaic echelle grating is shown on a Newport optical workstation. (Image credit:Richardson Gratings)

Rochester, NY--A large mosaic echelle grating was manufactured and shipped by Richardson Gratings, a Newport Corporation business, for use in the Habitable Zone Planet Finder. Contracted by the Pennsylvania State University, this 214 x 840 x 125 mm grating has 31.6 grooves per millimeter and a nominal blaze angle of 75 degrees. The mosaic grating was fabricated as a monolithic gold-coated replica grating from two matched gratings from the same echelle master. The fifteenth mosaic echelle produced by Richardson Gratings, the company says it possesses excellent performance characteristics as measured by spectral resolution, efficiency, blaze angle, wavefront, and alignment between the two segments.

The peak unpolarized diffraction efficiency meets or exceeds 60% for diffracted orders peaking between 900 and 1650 nm. Spectral resolving power was measured to exceed 1,190,000 at 633 nm, and spatial resolution was measured to be better than two seconds of arc. The overall diffracted wavefront demonstrates irregularity less than 0.06 waves at 633 nm.

The Habitable Zone Planet Finder (HzPF) is a cooled, fiber-fed, high resolution near-infrared echelle spectrograph developed at the Pennsylvania State University for the Hobby-Eberly telescope, which is housed at the McDonald Observatory in Texas. HzPF will be capable of discovering low-mass planets around cool, nearby stars as well as determining if these planets are in orbits that allow liquid water to exist on their surfaces, the so-called “habitable zone” around stars. The spectrograph will cover the wavelength range from 900 to 1650 nm to enable precise radial velocities as low as one meter per second--the speed of a person walking.

For further information on the HzPF, see Mahadeven et al., “The Habitable Zone Planet Finder: A Proposed High Resolution NIR Spectrograph for the Hobby Eberly Telescope to Discover Low Mass Exoplanets around M Dwarfs,” Proc. SPIE 7735 (2010) (http://arxiv.org/ftp/arxiv/papers/1007/1007.3235.pdf).

SOURCE: Richardson Gratings; http://www.gratinglab.com/News/News.aspx

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