基于复合式微纳光纤锁模器件的单腔多光频梳技术研究

光纤滤波器与锁模器件作为实现波长复用式单腔双光频梳光源的核心组件受到了研究者们的广泛关注。针对传统滤波器对偏振敏感、制作工艺复杂的问题,研制了一种基于微纳光纤的复合式器件,采用熔融拉锥方式进行微纳器件的制作,利用模间干涉产生滤波效应,利用热泳效应实现光沉积。将该复合器件应用于环形腔中,实现了1532,1543,1555 nm 的多波长锁模,且在不同偏振态下,波长漂移均不高于0.2 nm。该复合器件为实现单腔双光频梳、单腔三光频梳提供了新的解决方案,对于促进多光频梳技术在精密测量等领域的应用具有重要意义。     

光梳光谱仪技术及其应用

光学频率梳具有频谱范围宽、频率稳定等优点,在精密测量领域得到广泛应用。本文介绍了国内外光梳光谱仪的研究现状与技术原理,并在此基础上设计的一套Pound-Derver-Hall(PDH)腔长稳定的光梳光谱仪装置模型,为光梳在气体计量领域的应用研究打下基础。     

基于飞秒光学频率梳的双通道光频测量设计

基于差频技术的单块飞秒光学频率梳被广泛应用于光频的精密测量领域.通过将飞秒激光的重复频率和载波包络相移同时锁定至原子钟上,可以将飞秒光学频率梳的稳定状态延长至9h.文中提出了一种基于飞秒光学频率梳的双通道光频测量设计,并且针对两种待测光频的不同情况,给出了不同的测量方法.这种设计对将来实现高效率的光频测量具有重要意义.     

基于光频梳的乙炔稳频1542 nm激光波长测量研究

利用光频梳对稳频激光波长进行测量是建立基于光频梳的波长基标准的必经程序。为了建立基于光频梳的波长标准,并为开展激光波长校准工作提供技术准备,利用自研光纤光频梳对乙炔稳频1542 nm激光波长进行了测量。利用光频梳产生参考激光与待测激光差拍,通过简单的代数关系获得了乙炔稳频激光的绝对频率和真空波长,并与相应的国际推荐值进行了对比。实测获得的乙炔稳频激光的真空波长值为1542.38 371 235 742 nm,在CIPM给定的不确定度范围内,秒稳定度为4.13×10-13。两台不同的光频梳对乙炔稳频激光波长的测量结果具有高度一致性,进一步证明了光频梳对激光波长的测量准确性。本研究对于顺应国际长度基标准发展趋势,加速光频梳在激光波长测量领域的应用进程具有重要意义。     

单腔双光梳激光器及其应用研究

双光梳技术凭借其超高的频率分辨力与检测精度成为当今科研领域探索的重点。本文分别介绍了利用电光调制、微谐振腔、相位锁定两台独立的锁模激光器、单腔双光梳激光器产生双光梳的方法,重点阐述了基于单腔双波长激光器的双光梳产生方法集成度高、结构较简单、成本低的优势;之后详细介绍了目前单腔双光梳激光器中,双波长腔内运转的脉冲波形复用法、空间复用法、方向复用法、波长复用法和偏振复用法的工作原理及最前沿的研究进展;最后,具体分析了单腔双光梳在光谱学、测距、光纤传感等领域的应用情况,并展望未来单腔双光梳的研究与发展方向,为推动单腔双光梳技术性能的进一步提升和广泛应用提供借鉴。     

"飞秒激光光学频率梳的研究"通过专家鉴定

计本刊讯(记者马靖通讯员卢敬叁)9月12日,由中国计量科学研究院承担的“飞秒激光光学频率梳的研究”顺利通过鉴定委员会专家的鉴定。该研究成果成功将我国633nm氦氖国家激光波长基准的频率直接溯源到国家铯原子时间频率基准,从根本上解决了我国激光波长基准必须通过国际比对才能实现量值溯源的问题。“飞秒激光光学频率梳的研究”是通过飞秒光梳技术使微波频率与光学频率得到链接,实现了激光频率的直接绝对测量,这项技术被科学界视为光频测量领域的突破性成就。“飞秒光梳”技术是世界科技前沿项目,也是计量学研究的重要课题之一。2001年,中…     

钙离子光频标钟跃迁绝对频率测量

回顾了中国科学院精密测量科学与技术创新研究院对钙离子光频标钟跃迁绝对频率的测量工作，并对测量结果被国际计量委员会（CIPM）下属的时间频率咨询委员会（CCTF）采纳的情况进行了总结和描述。在2011～2020年间，利用实验室型光频标和可搬运光钟，采用基于飞秒光梳和卫星链路的方案溯源到国际秒定义，及基于飞秒光梳直接溯源到中国计量科学研究院铯喷泉微波钟的方案，多次测量了钙离子光频标钟跃迁绝对频率，测量不确定度从10^-15量级逐步提高到10^-16量级，共计4个测量结果被CCTF采纳。参与钙离子光频标钟跃迁频率国际推荐值的计算，分别于2012年、2015年、2017年和2021年先后四次更新了钙离子光频标钟跃迁频率推荐值。钙离子光频标钟跃迁于2021年被推荐为新增的“秒的次级表示”。     

用差频腔产生覆盖633nm光谱的飞秒激光频率梳

飞秒激光频率梳被认为是连接光频和无线电频率的一个超精密齿轮,比较了自参考法锁相稳频飞秒激光频率梳和差频法单块结构飞秒激光频率梳的特点,前者光谱范围宽,但稳定性较差;后者稳定性较好,但光谱范围较窄。在差频腔单块结构飞秒激光频率梳的基础上,通过使用腔外压缩色散补偿方式压缩激光脉冲宽度,然后重新注入光子晶体光纤进行光谱扩展,获得了覆盖633nm波长的更宽的光谱范围,为633nm波长激光频率测量创造了条件。     

中国计量测试学会科学技术进步奖获奖项目简介

<正>一等奖基础进步奖掺Er光纤飞秒光学频率梳的研究与应用近年来,作为新一代飞秒光梳技术的掺Er光纤飞秒光学频率梳,已成为飞秒光梳技术发展的主流方向并逐步突破时间频率领域,成为许多高端研究领域的基础性科学仪器。中国计量科学研究院首次在国内研制成功了基于掺Er光纤飞秒激光器的光学频率梳,具有填补了国内掺Er光纤光梳的技术空白,满足了国家波长基     

633nm波长副基准光频绝对测量实验

为了进行光频的绝对测量实验研究,本课题组研制了基于MgO:PPLN晶体的"单块"结构飞秒激光频率梳,在利用稳频电路将重复频率frep和载波包络相移频率fceo同时锁定到氢原子钟上后,其光频齿的频率稳定度同步于氢原子钟。利用该高稳定度"单块"结构钛宝石飞秒激光频率梳对编号为NO.02的633nm激光波长国家副基准装置进行了激光频率的绝对测量实验,得到了5个峰的测量结果,各光频测量结果相对偏差为10-11量级。     

全固态飞秒光学频率梳研究进展及展望

自1999年至今,光学频率梳（Optical Frequency Comb,OFC）经历了二十多年的快速发展。基于飞秒激光的光学频率梳在频率计量学、超快光谱学、光学频率标准、阿秒脉冲的产生、多脉冲时域合成等众多前沿研究领域中发挥了不可替代的作用。特别是继飞秒钛宝石激光频率梳、飞秒光纤激光频率梳之后,基于二极管激光直接泵浦的全固态飞秒激光频率梳由于兼具钛宝石激光噪声低、重复频率高,光纤激光结构紧凑、电光效率高的共同优势,引起了许多研究组的兴趣,并取得系列有意义的进展。本文综述了全固态光学频率梳的发展和已取得的典型应用,并结合笔者所在课题组取得的研究成果,对全固态光学频率梳未来的发展方向进行展望,为促进全固态飞秒锁模振荡器的发展提供借鉴。     

双光梳光谱测量技术

双光梳光谱技术是一种先进的精密光谱测量技术,具有高分辨力、高频率精度、快速测量和宽带光谱覆盖等优点,已在光谱激光雷达、温室气体监测、燃烧诊断等测量领域中广泛应用。关于双光梳光谱的新原理、新方案和新技术不断涌现,因此有必要对其发展现状进行梳理和总结。本文详细地阐述了双光梳光谱技术的原理和性能指标,分析对比了光频参考、电光调制、单腔双光梳和光调制四种典型双光梳光谱测量系统的实验方案和优势,同时具体分析了双光梳光谱技术在工作波段拓展方向的发展现状,最后对双光梳光谱系统的发展趋势和应用前景进行了总结和展望,为双光梳光谱技术在全波段光谱测量和多场景应用中的进一步提升提供参考。     

Precision spectroscopy of hydrogen and femtosecond laser frequency combs

Precision spectroscopy of the simple hydrogen atom has inspired dramatic advances in optical frequency metrology: femtosecond laser optical frequency comb synthesizers have revolutionized the precise measurement of optical frequencies, and they provide a reliable clock mechanism for optical atomic clocks. Precision spectroscopy of the hydrogen 1S-2S two-photon resonance has reached an accuracy of 1.4 parts in 10(14), and considerable future improvements are envisioned. Such laboratory experiments are setting new limits for possible slow variations of the fine structure constant alpha and the magnetic moment of the caesium nucleus mu(Cs) in units of the Bohr magneton mu(B).     

Dual-Comb Ranging

Absolute distance measurement is a fundamental technique in mobile and large-scale dimensional metrology. Dual-comb ranging is emerging as a powerful tool that exploits phase resolution and frequency accuracy for high-precision and fast-rate distance measurement. Using two coherent frequency combs, dual-comb ranging allows time and phase response to be measured rapidly. It breaks through the limitations related to the responsive bandwidth, ambiguity range, and dynamic measurement characteristics of conventional ranging tools. This review introduces dual-comb ranging and summarizes the key techniques for realizing this ranging tool. As optical frequency comb technology progresses, dual-comb ranging shows promise for various professional applications.     

Optical frequency measurements with the global positioning system: tests with an iodine-stabilized He-Ne laser

Global positioning system- (GPS-) referenced optical frequency combs based on mode-locked lasers offer calibrations for length metrology traceable to international length standards through the SI second and the speed of light. The absolute frequency of an iodine-stabilized He-Ne laser [127I2 R(127) 11-5 f component] was measured with a femtosecond comb referenced to a multichannel GPS timing receiver. The expected performance and limitations of GPS-referenced comb measurements are discussed.     

Optical Frequency Metrology of an Iodine-Stabilized He-Ne Laser Using the Frequency Comb of a Quantum-Interference-Stabilized Mode-Locked Laser

We perform optical frequency metrology of an iodine-stabilized He-Ne laser using a mode-locked Ti:sapphire laser frequency comb that is stabilized using quantum interference of photocurrents in a semiconductor. Using this technique, we demonstrate carrier-envelope offset frequency fluctuations of less than 5 mHz using a 1 s gate time. With the resulting stable frequency comb, we measure the optical frequency of the iodine transition [¹²⁷I₂ R(127) 11-5 i component] to be 473 612 214 712.96 ± 0.66 kHz, well within the uncertainty of the CIPM recommended value. The stability of the quantum interference technique is high enough such that it does not limit the measurements.     

Industrial applications of optical techniques that measure displacements

Full-field optical techniques have reached a level of development that makes them ideal tools to solve many practical industrial problems. The areas of application include metrology; nondestructive evaluation of components; solutions to stress analysis problems, both static and dynamic; and development of sensors. In metrology, of particular significance are problems of three-dimensional (3-D) shape measurement. The shape measurement is connected to computer-aided design/computer-aided manufacturing programs, rapid prototyping, and reverse engineering. Unlike tactile machines that provide single-point data, optical methods provide high-density information, and their accuracy has reached a level comparable to tactile machines. This information makes feasible a number of new applications of high industrial interest in reverse engineering. Another area of great interest is 3-D visualization. Other areas of growth are the detection of flaws in nondestructive evaluation, problems arising from dynamic effects, refining of modeling techniques, and development of new sensors. A completely new area of application is the use of optical techniques in the field of microelectromechanical systems and in the area of nanosciences. Very recent work shows that one can go beyond the Rayleigh limit and obtain information at the nanolevel. It is possible to anticipate that a great expansion will take place in these fields in the next few years.     

对计量内涵及其发展重点的思考

针对当前计量工作存在滞后于产业发展、与产业需求脱节的问题,从计量的基本理论、历史沿革和应用实践出发,通过分析计量的内涵、计量与测量的关系,并结合现阶段计量体系架构和实际工作开展情况,探讨计量工作在管理、技术和理念等方面存在的问题,聚焦测量需求、测量过程、测量标准、测量结果等测量体系组成要素,提出计量与产业融合发展的切入点,为当前质量强国、数字强国背景下充分发挥计量作用提供参考。     

Optical frequency standards and measurement

This paper celebrates the progress in optical frequency standards and measurement, won by the 40 years of dedicated work of world-wide teams working in frequency standards and frequency measurement. Amazingly, after this time interval, the field is now simply exploding with new measurements and major advances of convenience and precision, with the best fractional frequency stability and potential frequency accuracy now being offered by optical systems. The new "magic" technology underlying the RF/optical connection is the capability of using femtosecond (fs) laser pulses to produce optical pulses so short their Fourier spectrum covers an octave bandwidth in the visible. These "white light" pulses are repeated at stable rates (/spl sim/100 MHz to 1 GHz, set by design), leading to an optical "comb" of frequencies with excellent phase coherence and stability and containing some millions of stable coherent optical frequencies. Optical-heterodyned differences between comb lines provides a frequency-related RF or microwave output with remarkably low added phase noise, such that in an optically-based atomic clock, the phase noise of the standards-grade microwave frequency reference dominates over that of optical reference and the fs "gear-box".