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题名	原子芯片陀螺仪关键技术研究进展
作者	蒋小军
学位类别	博士
答辩日期	2016
授予单位	中国科学院上海光学精密机械研究所
导师	王育竹
关键词	导引型原子陀螺仪 原子芯片 环形波导 相干分束 电磁感应透明
其他题名	Progress of the key technology of atom gyroscope on a chip
中文摘要	本论文介绍了作者在攻读博士期间有关研制原子芯片陀螺仪关键技术上的理论和实验工作。原子陀螺仪以原子光学和量子力学为理论基础，其原理是基于物质波动特性和萨格纳克效应的原子干涉仪。利用激光冷却和囚禁技术可以获得极小的速度及其速度分布的冷原子云，并且可以精确地控制原子速度以及与激光交互作用时间，有可能使原子陀螺仪系统的尺寸更小、精度更高。因此以冷原子作为工作物质的干涉陀螺仪有可能成为提高惯性导航性能的关键技术。原子陀螺仪分为自由飞行型和导引型两种。相比较于自由飞行型的原子陀螺仪，导引型原子陀螺仪可以做到集成化和小型化。 环形波导是导引型原子陀螺仪的核心器件。我们提出了基于阿基米德螺线的环形导引。通过一个简单的直流电流，就可以在芯片表面产生环形导引。利用阿基米德螺线，在单层芯片上可以避免由于电流的流入和流出而产生的环形导引缺口。阿基米德螺线型环形导引的位置仅由芯片导线的布局所决定而与电流和外加偏置磁场无关，因此具有极高的稳定性。通过改变阿基米德螺线的半径可以制作不同回路面积的环形导引。在加上一个旋转偏置磁场后可以有效的平滑环形导引，并且可以避免原子由于马约拉纳跃迁而从磁阱中逃出。 通过优化我们的原子芯片系统和蒸发冷却方法，我们获得了原子数约为2.5×104个，温度低于200 nK的超冷原子云。我们研究了利用磁场和光场对冷原子进行分束。通过U线电流，我们可以将Z阱中的冷原子分裂为相距超过1mm，比率接近50/50的两团原子。利用双脉冲驻波场可以将原子分成动量为±2?k 两团原子 。我们利用TE5351信号发生器和声光调制器(AOM)获得了精确控制的双脉冲驻波场，并且实现了驻波场对冷原子的对准，观察到了对准光对冷原子的推动作用。 本论文的另外一项内容介绍了作者在87Rb冷原子的塞曼子能级上的电磁感应透明的实验工作，这是我们小组开展的相干存储冷原子钟的前期工作。我们使用87Rb 原子D2线的超精细结构 52S1/2, F=2 和 52P3/2, F'=2 的塞曼子能级形成Λ构型的EIT能级，通过固定控制光频率，并使用80MHz的任意信号发生器在4 ms内对探测光扫描1 MHz 获得了EIT信号。我们观察到了100 kHz的EIT窗口和超过97% 的透明度。
英文摘要	This thesis presents my work on the progress of the key technology of atom gyroscope on a chip.The atom gyroscope is based on atom optics and quantum mechanics, which principle is the wave-particle duality of matter and Sagnac effect. By using laser cooling and magnetic trapping technology, we can capture cold atoms with very low velocity and narrowing velocity distribution. We also can precisely control the speed of atoms and the interaction time between atoms and laser, which could minimize the volume of the system and improve the sensitivity. The cold atom gyroscope offers the prospect of improving the sensitivity of Inertial navigation sensor. There are two kinds of atom gyroscope, unguided and guided. Compared with the unguided atom gyroscope, the guided atom gyroscope can integrate other components and minimize the volume of the system. The ring waveguide is one of the key element of the guided atom gyroscope. We have present a scheme to generate a ring magnetic waveguide on a single-layer atom chip. The wire layout based on Archimedes spiral can generate a ring waveguide with a simply constant current and without external bias field, which avoids the trapping notch caused by the input and output ports, resulting in an enclosed guiding loop for neutral atoms. The waveguide is very stable as the location of the waveguide is immune to the magnetic variations as it's only determined by the wire layout. The scheme has the ability to create various sizes of enclosed area ring waveguide by adjusting the radius of Archimedean-spirals. By using a rotation bias field, the minimum of the time-averaged orbiting potential is lifted from zero, and then a relatively smooth and harmonic ring trap is formed. We have captured almost 2.5×104 atoms with a temperature of below 200 nK by optimizing our system and the process of evaporative cooling. We have studied the the splitting of cold atoms in spatial domain and momentum space. We have experimentally demonstrated a simple scheme of splitting cold atoms in spatial domain on atom chip. By switching on the current of the U-wire, the atom cloud in the Z-trap has been split into two separate parts, which show almost symmetrical profiles, corresponding to an about 50/50 splitting ratio. The two atom clouds have a distance more than one millimeter apart from each other. With a sequence of two standing-wave square pulses, the cold atom cloud can be split into ±2?k diffraction orders. We use the arbitrary waveform generator TE5351 and a acousto-optic modulator (AOM) to control the pulse precisely. We have realize the alignment of the standing-waves and the cold atoms and the pushing effect of the alignment laser has been observed. Another work of this thesis is the experimental demonstration of electromagnetically induced transparency (EIT) in a Zeeman-sublevels Λ -type system of cold 87 atoms, which is the prior work of pulsed coherent storage atomic clock. We use the Zeeman substates of the hyperfine energy states 52S1/2, F=2 and 52P3/2, F'=2 of 87Rb D2 line to form a Λ -type EIT scheme. The EIT signal is obtained by scanning the probe light over 1 MHz in 4 ms with an 80 MHz arbitrary waveform generator. More than 97% transparency and 100 kHz EIT window are observed.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15976]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	蒋小军. 原子芯片陀螺仪关键技术研究进展[D]. 中国科学院上海光学精密机械研究所. 2016.

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