Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region
Zinc sulfide and zinc selenide immersion gratings for astronomical high-resolution spectroscopy: evaluation of internal attenuation of bulk materials in the short near-infrared region
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DOI：
10.1117/1.3206734
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发表时间：
2009-08-01
影响因子：
1.3
通讯作者：
Terada, Hiroshi
中科院分区：
文献类型：
--
作者：
Ikeda, Yuji;Kobayashi, Naoto;Terada, Hiroshi
我们测量了化学气相沉积硒化锌（CVD-ZnS）、化学气相沉积硫化锌（CVD-ZnSe）、Si和GaAs的体晶体在短近红外（sNIR）区的内部衰减，以评估用这些高折射率材料制作天文浸没光栅的可能性。我们确认，多光谱级CVD-ZnS和CVD-ZnSe是最适合的浸没式光栅，与最小的内部衰减α（att）= 0.01至0.03厘米（-1）之间的主要候选人。测得的衰减大致与λ（-2）成比例，表明它是由多晶晶粒引起的体散射而不是吸收主导的。即使对于R = 300，000的光谱分辨率，浸没光栅中的总透射率估计为至少> 80%。两个潜在的问题，散射光的散装材料和光谱分辨率的退化，由于在衍射光束的梯度照明，进行了研究，发现是可以忽略不计的通常的天文应用。由于剩下的问题，在CVD-ZnS和CVD-ZnSe上切割凹槽的困难，最近已经被纳米精密飞切技术克服，用于天文学的ZnS和ZnSe浸没光栅可以在技术上实现。(C)2009年，由光学仪器工程师协会（Society of Photo-Optical Instrumentation Engineers）主办。[DOI 10.1117/1.3206734]
We measure the internal attenuation of bulk crystals of chemical vapor deposition zinc selenide (CVD-ZnS), chemical vapor deposition zinc sulfide (CVD-ZnSe), Si, and GaAs in the short near-infrared (sNIR) region to evaluate the possibility of astronomical immersion gratings with those high refractive index materials. We confirm that multispectral grade CVD-ZnS and CVD-ZnSe are best suited for the immersion gratings, with the smallest internal attenuation of alpha(att) = 0.01 to 0.03 cm(-1) among the major candidates. The measured attenuation is roughly in proportion to lambda(-2), suggesting it is dominated by bulk scattering due to the polycrystalline grains rather than by absorption. The total transmittance in the immersion grating is estimated to be at least >80%, even for the spectral resolution of R = 300,000. Two potential problems, the scattered light by the bulk material and the degradation of the spectral resolution due to the gradient illumination in the diffracted beam, are investigated and found to be negligible for usual astronomical applications. Since the remaining problem, the difficulty of cutting grooves on CVD-ZnS and CVD-ZnSe, has recently been overcome by the nanoprecision fly-cutting technique, ZnS and ZnSe immersion gratings for astronomy can be technically realized. (C) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3206734]