排序方式: 共有16条查询结果,搜索用时 15 毫秒
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报道了自主研制的面向Li原子D1线频率测量应用的掺铒飞秒光纤光学频率梳,包括飞秒激光源,频率探测及控制单元,光谱展宽及拍频单元.光纤光梳系统中飞秒激光光源是一套基于非线性偏振旋转锁模机制的掺铒飞秒光纤激光器,重复频率为196.5MHz,中心波长为1 572nm.利用f-2f法探测载波包络相移频率,获得信噪比约为40dB的信号(分辨率带宽300kHz).改变飞秒激光光源泵浦控制载波包络相移频率、频率稳定度是3.74×10-18/τ1/2;通过电光晶体和压电陶瓷改变飞秒激光光源腔长来控制重复频率frep、频率稳定度是1.75×10-13/τ1/2.利用高非线性光纤和倍频晶体将光纤光梳直接输出光谱由1 520~1 607nm扩展到671nm,获得了单模功率为208nW的光信号.与671nm单频激光拍频产生约为60dB(分辨率带宽1Hz)信号,满足Li原子D1线频率测量实验的需求. 相似文献
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含有不同的链长的w-吡咯烷基二甲基氯硅烷作为粘合剂通过自组装(SAMs)吸附于二氧化硅表面,然后聚吡咯膜化学沉积于该粘合剂修饰的表面。化学沉积的聚吡咯膜的表面形貌用扫描电镜(SEM)及原子力显微镜(AFM)表征。除短链外不同链长的粘合剂对聚吡咯膜的厚度影响不大。聚吡咯膜的电特性用电流-电压表征。结果显示电流与粘合剂的链长无关。电特性表明载流子迁移率为1.4 ´ 10-4 cm2×V-1.s –1。 相似文献
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We present an experimental and theoretical study of self-rotation of optical polarization in a rubidium vapor.The atomic vapor is placed in a magnetic shielding cavity to suppress the Faraday rotation effect.In our experiment,Doppler-free spectroscopy configuration is used,and F = 2 → F ’ = 3 transition of 87Rb D2 line is chosen.We observe self-rotation of optical polarization effect at different pump light ellipticities.A theoretical analysis is then provided based on the experimental conditions.Theoretical simulation and experimental results are in good agreement. 相似文献
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Photonic generation of RF and microwave signal with relative frequency instability of 10~(-15) 下载免费PDF全文
We demonstrate the ultra-stable frequency sources aiming to improve the short-time instability of primary frequency standards. These sources are realized by using photonic generation approach, and composed of ultra-stable lasers, opticalfrequency-combs, optical signal detecting parts, and synthesizers. Preliminary evaluation shows that the sources produce fixed-frequency at 9.54(/9.63) GHz, 10 MHz, and tunable-frequency around 9.192 GHz with relative frequency instability of 10~(-15) for short terms. 相似文献
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报道了利用50 km光纤实现4.38×10~(-15)@1 s和2.80×10~(-18)@65.5×10~3s稳定度的微波频率传递的实验研究.实验系统采用多普勒噪声消除技术,通过在本地端探测往返传递的微波信号相位获得链路上的相位变化信息,并实时控制光延迟调整机构进行补偿.光延迟控制采用压电陶瓷的快速拉伸和慢速光纤温控联合方式,可实现5 ns和千赫兹带宽的光延迟控制,能够实现光纤噪声的长期高精度补偿.与电相位补偿相比,光延迟补偿受微波泄露的影响相对较小,而微波泄露影响在类似系统难以避免,因此这种方式更利于获得高稳定度的频率传递.此外,系统采用变频往返传递消除光寄生反射效应,以及色散补偿光纤减小因色散引起的调制信号衰减等措施,提高了系统的技术指标. 相似文献
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