论文标题
1兆像素的近红外雪崩光电二极管阵列的首次测试用于超低背景天文学
First tests of a 1 megapixel near-infrared avalanche photodiode array for ultra-low background space astronomy
论文作者
论文摘要
接下来几十年的优先科学案例，类似地球的系外行星和超品种星系的光谱学是优先的。在这里，宽带源通量率以每小时/平方米的光子为单位测量，对检测器性能的极端需求，包括低于1 e-/e-/pixel/kilosecond的深色电流，读取小于1 e-/pixel/frame的噪声和大型格式。目前没有符合这些要求的红外探测器。夏威夷大学和工业合作伙伴正在开发一种有前途的技术，即线性模式雪崩光电二极管（LMAPDS），使用对HGCDTE带盖结构的精细控制，以实现无噪声的电荷放大和最小的光芒。 在这里，我们报告了在低温测试床上运行的原型百万像素格式的第一个结果。在50开尔文时，我们测量了大约3 e-/pixel/kilsecond的暗电流，这是由于内在的深色电流与零一致（最佳估计为0.1 e-/pixel/kilosecond）和0.08 e-/pixel/frage的ROIC光芒。这些设备的读取噪声约为3伏的10 e//像素/框架，每增加一个偏置伏特，在8伏时降低30％。预计即将到来的科学级设备将对这些数字有所改善，并解决测试过程中发现的其他问题。
Spectroscopy of Earth-like exoplanets and ultra-faint galaxies are priority science cases for the coming decades. Here, broadband source flux rates are measured in photons per square meter per hour, imposing extreme demands on detector performance, including dark currents lower than 1 e-/pixel/kilosecond, read noise less than 1 e-/pixel/frame, and large formats. There are currently no infrared detectors that meet these requirements. The University of Hawaii and industrial partners are developing one promising technology, linear mode avalanche photodiodes (LmAPDs), using fine control over the HgCdTe bandgap structure to enable noise-free charge amplification and minimal glow. Here we report first results of a prototype megapixel format LmAPD operated in our cryogenic testbed. At 50 Kelvin, we measure a dark current of about 3 e-/pixel/kilosecond, which is due to an intrinsic dark current consistent with zero (best estimate of 0.1 e-/pixel/kilosecond) and a ROIC glow of 0.08 e-/pixel/frame. The read noise of these devices is about 10 e-/pixel/frame at 3 volts, and decreases by 30% with each additional volt of bias, reaching 2 e- at 8 volts. Upcoming science-grade devices are expected to substantially improve upon these figures, and address other issues uncovered during testing.
