Photonic spatial reformatting of stellar light for diffraction-limited spectroscopy
Photonic spatial reformatting of stellar light for diffraction-limited spectroscopy
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DOI：
10.1093/mnras/stv410
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发表时间：
2015-06-11
影响因子：
4.8
通讯作者：
Thomson, R. R.
中科院分区：
文献类型：
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作者：
Harris, R. J.;MacLachlan, D. G.;Thomson, R. R.
色散摄谱仪的光谱分辨率取决于入射狭缝的宽度。这意味着天文摄谱仪要在吞吐量和光谱分辨率之间进行权衡。最近，被称为光子灯笼的光学导波转换已经被提出来规避这种权衡，通过使多模光能够有效地重新格式化为伪狭缝，该伪狭缝在一个轴上是高度多模的，但在另一个轴上是衍射受限的。在这里，我们展示了成功的重新格式化的望远镜点扩散函数到这样的狭缝使用三维集成光波导器件，我们命名为光子切丁机。使用威廉·赫歇尔望远镜上的CANARY自适应光学（AO）演示器，以及中心在1530 nm处的光，半峰全宽为160 nm，该设备显示出10%至20%的透射率，具体取决于所应用的AO校正类型。大部分损失是由于在较差和中等视宁度下输入孔径的过度填充。考虑到这一点，光子器件本身的透射率为57 +/-4%.We展示了如何将完全优化的器件与AO一起使用，以提供高光谱分辨率的高效光谱。
The spectral resolution of a dispersive spectrograph is dependent on the width of the entrance slit. This means that astronomical spectrographs trade-off throughput with spectral resolving power. Recently, optical guided-wave transitions known as photonic lanterns have been proposed to circumvent this trade-off, by enabling the efficient reformatting of multimode light into a pseudo-slit which is highly multimode in one axis, but diffraction-limited in the other. Here, we demonstrate the successful reformatting of a telescope point spread function into such a slit using a three-dimensional integrated optical waveguide device, which we name the photonic dicer. Using the CANARY adaptive optics (AO) demonstrator on the William Herschel Telescope, and light centred at 1530 nm with a 160 nm full width at half-maximum, the device shows a transmission of between 10 and 20 per cent depending upon the type of AO correction applied. Most of the loss is due to the overfilling of the input aperture in poor and moderate seeing. Taking this into account, the photonic device itself has a transmission of 57 +/- 4 per cent. We show how a fully-optimized device can be used with AO to provide efficient spectroscopy at high spectral resolution.