MEMS Shutter Array for Astronomical Infrared Spectrograph of Deep Galaxies

天文多目标摄谱仪（MOS）正在成为深入观测星系的有力工具。当人们观察数十亿光年外的深空时，可以在一个很小的视角内发现数百万个星系。通过近红外多普勒频移知道每个星系的距离是了解宇宙形成之初星系形成过程的第一步。然而，光子的数量是有限的，在他们旅行了很长一段距离后，通常需要很长时间才能从一个星系获得清晰的波长光谱。因此，MOS系统被用来最好地利用观测时间，一次观测几个目标星系。我们已经开发了一种用于天文望远镜的电驱动微快门阵列，用于多天体的红外光谱。快门阵列采用SOI硅微机械加工和深反应离子刻蚀技术制作。快门阵列由100微米× 1000微米的1 × 7个元件组成，快门板由一对仅1微米宽、2微米厚和450微米长的薄硅梁支撑。将快门从零平坦位置打开到90度的典型驱动电压为100 V - 200 V，这取决于悬架尺寸。在本文中，我们报告了两种类型的快门后，提高了操作的可靠性，快门是独立寻址和电闩锁与相对较低的保持电压为27 V。

Astronomical multi-object spectrographs (MOSs) are becoming a powerful tool for the deep survey of the galaxies. Millions of galaxies can be found in a small fraction of view angle when one looks into the deep space over billions of light years. Knowing the distance to each galaxy by the near-infrared Doppler shift is the first step to understand the process of galaxy formation at the beginning of the universe. However, the number of photons is limited after their having traveled a long distance and it usually takes long time to have a clear wavelength spectrum from one galaxy. For this reason, the MOS system has been employed to make best use of the observatory time by observing several target galaxies at a time. We have developed an electrically driven micro-shutter array for an astronomical telescope with an infrared spectroscopy for multiple celestial objects. The shutter array was made by the SOI silicon micromachining with deep reactive-ion etching. The shutter array consists of 1 x 7 elements of 100 microns by 1000 microns shutter plate supported by a pair of thin silicon beams of only 1 micron wide, 2 microns thick, and 450 microns long. Typical drive voltage to open the shutter from the zero flat position to 90 degrees was 100 V - 200 V, depending on the suspension dimensions. In this paper, we report two types of shutters after improving the operation reliability; the shutters are independently addressed and electrically latched with relatively low hold voltage of 27 V.