Perfect blazing for transmission gratings

“…The power distribution between the different orders and within a given order as a function of wavelength, however, depends on the groove geometry: the shape of the individual grooves, their orientation with respect to the grating normal, and the width of the grooves relative to the size of the spacing between them. Derivation of the blaze function is complex and requires detailed calculation of the electromagnetic behavior of the groove structure, taking into account the geometry, the material properties, and the polarization of the radiation (Nevière et al 1990;Neviere 1991). The most common sorts of infrared grisms for astronomy either employ flat-faceted grooves that fill the groove intervals and have 90 • corners or, in the case of micro-machined Si grisms, flat-faceted grooves with 70 • vertices and small (filling-factor ∼ 10%) lands parallel to the grating surface in between the facets (Figure 3).…”

Section: Blazementioning

confidence: 99%

A Grism Design Review and the As-Built Performance of the Silicon Grisms forJWST-NIRCam

Deen¹,

Gully-Santiago²,

Wang³

et al. 2017

PASP

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Grisms are dispersive transmission optics that find their most frequent use in instruments that combine imaging and spectroscopy. This application is particularly popular in the infrared where imagers frequently have a cold pupil in their optical path that is a suitable location for a dispersive element. In particular, several recent and planned space experiments make use of grisms in slitless spectrographs capable of multi-object spectroscopy. We present an astronomer-oriented general purpose introduction to grisms and their use in current and future astronomical instruments. We present a simple, step-by-step procedure for adding a grism spectroscopy capability to an existing imager design. This procedure serves as an introduction to a discussion of the device performance requirements for grisms, focusing in particular on the problems of lithographically patterned silicon devices, the most effective grism technology for the 1.1-8 micron range. We begin by summarizing the manufacturing process of monolithic silicon gratings. We follow this with a report in detail on the as-built performance of parts constructed for a significant new space application, the NIRCam instrument on JWST and compare these measurements to the requirements.

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Diffraction Gratings WDM Components

Laude¹

Springer Series in Optical Sciences

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Perfect blazing for transmission gratings

Cited by 11 publications

References 6 publications

<title>Some recent applications of electromagnetic theory in optics</title>

<title>Some recent applications of electromagnetic theory in optics</title>

A Grism Design Review and the As-Built Performance of the Silicon Grisms forJWST-NIRCam

Diffraction Gratings WDM Components

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