论文标题
NIKA和NIKA2极化器的基于超材料的半波板的开发和应用
Development and application of metamaterial-based Half-Wave Plates for the NIKA and NIKA2 polarimeters
论文作者
论文摘要
上下文。在毫米和毫米的波长下运行的范围视野成像/极化仪器是了解磁场（MF）在将细丝材料引导到PRESTELLAR核心中的作用的基本工具，可为prestellar核心提供独特的见解，以在银河系形成区域的物理学中提供独特的见解。除其他主题外，在半乳酸外尺度上，AGN的极化观察将使我们能够限制喷气机的发射等离子体的物理条件和/或探索超新星残留物中灰尘物理的物理。安装在IRAM 30米的望远镜上的Kilo像素NIKA2摄像头今天代表了天文学家可用的最佳工具之一，可在260 GHz（1.15 mm）上在大型田地上同时生产强度/极化图。目的。在NIKA和NIKA2中的极化测量是通过快速调节总传入极化来实现的。最终，这可以安全地将小科学信号与大型且可变的大气背景区分开。方法。极化调制是通过在光束中插入快速旋转半波板（HWP）来实现的。为了允许广泛的视野观察，板必须大，直径超过250 mm。在12 Hz处的极化信号的调制也需要波板充足。此外，此关键光学元素必须在传输和差异相移方面表现出最佳的电磁特性。为此，使用网格过滤器技术开发了三个超材料HWP。开发前两个单波频HWP中获得的知识用于达到上一个双波段HWP的更具挑战性的性能要求。第一个和第三波板符合Nika和Nika2仪器的要求。结果。（删节）
CONTEXT.Large field-of-view imaging/polarimetry instruments operating at millimeter and submm wavelengths are fundamental tools to understand the role of magnetic fields (MF) in channeling filament material into prestellar cores providing a unique insight in the physics of galactic star-forming regions. Among other topics, at extra-galactic scales, polarization observations of AGNs will allow us to constrain the possible physical conditions of the emitting plasma from the jets and/or exploring the physics of dust inside supernova remnants. The kilo-pixel NIKA2 camera, installed at the IRAM 30-m telescope, represents today one of the best tools available to the astronomers to produce simultaneous intensity/polarimetry maps over large fields at 260 GHz (1.15 mm). AIMS.The polarization measurement, in NIKA and NIKA2, is achieved by rapidly modulating the total incoming polarization. This allows in the end to safely isolate the small science signal from the large, un-polarized and strongly variable, atmospheric background. METHODS.The polarization modulation is achieved by inserting a fast rotating Half-Wave Plate (HWP) in the optical beam. In order to allow wide field-of-view observations, the plate has to be large, with a diameter exceeding 250 mm. The modulation of the polarized signal, at 12 Hz, requires also the waveplate to be sufficiently light. In addition, this key optical element has to exhibit optimal electromagnetic characteristics in terms of transmission and differential phase-shift. For this purpose, three metamaterial HWPs have been developed using the mesh-filter technology. The knowledge acquired in developing the first two single-band HWPs was used to achieve the more challenging performance requirements of the last dual-band HWP. The first and the third waveplates met the requirements for both the NIKA and NIKA2 instruments. RESULTS.(abridged)
