Novel diffraction gratings for next generation Spectrographs with high spectral dispersion
Novel diffraction gratings for next generation Spectrographs with high spectral dispersion
复制标题
用于下一代高光谱色散光谱仪的新型衍射光栅
DOI：
10.1117/12.2231949
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
N. Ebizuka;et al.
作为一种透射型光栅，脊型起伏光栅和体相位全息光栅在天文观测仪器中有着广泛的应用。然而，SR光栅在高角度色散下难以实现高衍射效率，而VPH光栅在高衍射级下衍射效率较低。我们提出了新的光栅，解决这些问题。本文介绍了一种由高折射率棱镜和具有锐角脊的复制透射光栅组成的混合棱镜。双折射VPH（B-VPH）光栅包含各向异性介质，例如液晶，对于自然偏振和圆偏振，在第一衍射级处实现高达100%的衍射效率。准布拉格（QB）光栅由精确平行排列的长矩形反射镜组成，就像百叶窗一样，在高于4级衍射时可实现60%或更高的衍射效率。具有窄槽的体二元（VB）光栅在高于第6衍射级时也实现了60%或更高的衍射效率。反射面透射（RFT）光栅是一种具有锐角脊的SR光栅，在高于4级衍射时，衍射效率可达80%。
As a transmission grating, a surface-relief (SR) grating with sawtooth shaped ridges and volume phase holographic (VPH) grating are widely used for instruments of astronomical observations. However the SR grating is difficult to achieve high diffraction efficiency at high angular dispersion, and the VPH grating has low diffraction efficiency in high diffraction orders. We propose novel gratings that solve these problems. We introduce the hybrid grism which combines a high refractive index prism with a replicated transmission grating, which has sawtooth shaped ridges of an acute apex angle. The birefringence VPH (B-VPH) grating which contains an anisotropic medium, such as a liquid crystal, achieves diffraction efficiency up to 100% at the first diffraction order for natural polarization and for circular polarization. The quasi-Bragg (QB) grating which consists of long rectangular mirrors aligned in parallel precisely, like a window blind, achieves diffraction efficiency of 60% or more in higher than the 4th diffraction order. The volume binary (VB) grating with narrow grooves also achieves diffraction efficiency of 60% or more in higher than the 6th diffraction order. The reflector facet transmission (RFT) grating which is a SR grating with sawtooth shaped ridges of an acute apex angle achieves diffraction efficiency up to 80% in higher than the 4th diffraction order.