基于注入锁定法布里-珀罗激光器的光学双稳态及光存储研究

研究基于注入锁定法布里-珀罗激光器的全光双稳态效应及其在全光存储中的应用. 进行了法布里-珀罗激光器的注入锁定的实验研究, 对注入锁定的法布里-珀罗激光器的输出功率特性进行实验分析, 得到了不同注入光波长失谐量对迟滞曲线的门限宽度和消光比的影响. 进一步, 通过对控制信号功率的合理设置, 实现了对10 Gb/s输入信号的2.5 GHz光存储验证了利用注入锁定法布里-珀罗激光器实现高速全光存储的可行性, 在高速光纤通信领域具有极大的应用价值.     

利用法布里-珀罗腔抑制电光相位调制中的剩余幅度调制

激光经电光相位调制后,由于剩余幅度调制的存在造成调制边带幅度不相等。利用法布里-珀罗腔的透射特性和Pound-Drever-Hall技术对通过法布里-珀罗腔的调制光正、负一级边带的幅度产生不同的衰减,使得调制边带的幅度相等,从而实现对电光相位调制中剩余幅度调制的抑制。采用该方法,理论上计算了调制光经法布里-珀罗腔后的光外差光谱信号,获得锁定法布里-珀罗腔后调制边带幅度的不对称度较腔锁定前减小四个数量级。实验研究了调制光经法布里-珀罗腔透射的光外差光谱,结果表明将法布里-珀罗腔锁定于该透射光外差光谱中心零位时,对剩余幅度调制的抑制程度可达45 dB。     

半导体激光器塞曼调制稳频的实验对比研究

首先阐述了实现半导体激光器外调制锁频方案的必要性,并针对一种利用塞曼效应进行外调制稳频的实验方案,详细地阐述了其基本思想和实验原理,以及这种稳频方案相对于一般的内调制饱和吸收稳频技术在实验上的差异.本文给出的具体实验参数和实验结果表明,这种方案相对于其他方案可以获得同等好的锁频质量.不仅如此,本文还给出了塞曼调制稳频和电流调制稳频的锁定频率输出的监视对比情况,从对比结果中,我们可以清楚地看到塞曼调制稳频使得激光器锁定频率无调制输出的优越特性.     

激光二极管抽运的高输出单频稳频Nd∶YVO4激光器

研制了光纤耦合的激光二极管抽运的单频稳频Nd∶YVO4激光器。在输入抽运功率为 6W的情况下 ,获得 2W稳定单频红外输出 ,光光转换效率为 33 3% ,电光转换效率为 10 %。通过边带稳频系统将输出激光频率锁定在法布里珀罗共焦参考腔的中心频率上 ,频率稳定性优于 40 0kHz     

激光二极管抽运的高输出单频稳频Nd：YVO4激光器

研制了光纤耦合的激光二极管抽运的单频稳频Nd:YVO4激光器。在输入抽运动率为6W的情况下,获得2W稳定单频红外输出,光－光转换效率为33．3％,电－光转换效率为10％。通过边带稳频系统将输出激光锁定在法布里－珀罗共焦参考腔的中心频率上,频率稳定性优于400kHz。     

风场探测Fabry-Perot干涉仪定标与反演算法研究

利用非线性回归法结合仪器的传递函数模型对大气风场探测法布里-珀罗干涉仪进行了定标和反演.首先,基于修正的艾里函数建立了仪器的传递函数及气辉响应函数模型;然后,利用稳频激光器对现有法布里-珀罗干涉仪系统进行了实验室定标,获取了定标数据;采用分步非线性回归拟合法对定标数据进行处理,获取仪器传递函数模型参量;最后利用标定的仪器传递函数模型,对不同信噪比、不同风速温度预估输入的法布里-珀罗干涉仪气辉仿真数据进行了风速和温度反演.实验结果表明,在信噪比优于40的情况下,风速和温度反演准确度分别可以达到5m/s和10K.     

用于激光稳频系统的控温F-P标准具特性研究

法布里-珀罗标准具由于其结构简单、性能稳定,不仅可以实现不同频率光束的分离、高精度的长度测量、分析激光的纵模结构等,还可用于激光器的稳频系统。本文对F-P标准具的透射率、半高宽度、自由光谱区以及透射率与温度的关系等特性进行了研究,并将其应用在激光器的稳频装置中。     

基于飞秒光频梳的压电陶瓷闭环位移控制系统

利用飞秒光频梳、外腔可调谐半导体激光器和法布里-珀罗干涉仪建立了一套压电陶瓷亚纳米级闭环位移控制系统. 将可调谐半导体激光器锁定至光频梳, 通过精确调谐光频梳的重复频率, 实现了半导体激光器在其工作频率范围内的精密调谐. 利用Pound-Drever-Hall锁定技术将带有压电陶瓷的法布里-珀罗腔锁定至半导体激光器, 进而通过频率发生系统控制压电陶瓷产生亚纳米级分辨率的位移. 实验研究发现锁定至光频梳后可调谐半导体激光器1 s的Allan标准偏差为1.68×10^-12, 将其在30.9496 GHz范围内进行连续闭环调谐, 可获得压电陶瓷的位移行程约为4.8 μm; 以3.75 Hz的步长扫描光频梳的重复频率, 实现了压电陶瓷的450 pm闭环位移分辨率并测定了压电陶瓷的磁滞特性曲线. 该系统不存在非线性测量误差, 且激光频率及压电陶瓷位移均溯源至铷钟频率源. 关键词： 光频梳 压电陶瓷 法布里-珀罗腔 可调谐半导体激光器     

基于法布里-珀罗半导体激光器实现高重复频率光脉冲的时钟分频

实验研究了重复速率为6.32 GHz的光脉冲注人法布里-珀罗(Fabry-Perot)半导体激光器实现3.16 GHz光脉冲输出的时钟分频现象,讨论了 Fabry-Perot半导体激光器的偏置电流、注入光功率、注入光光谱以及光谱线宽等因素对时钟分频的影响.利用光注入半导体激光器产生的周期二振荡非线性动力学特性.实现了高重复速率光脉冲的时钟分频.研究表明,当注入光的光谱较窄且锁定Fabry-Perot半导体激光器某一纵模时,在较低的偏置电流和一定的注入光功率时,时钟分频才能发生.采用半导体激光器的速率方程.通过数值模拟,研究了半导体激光器的偏置电流和线宽增强因子以及注入光功率对时钟分频的影响,所得结果与实验结果相吻合.     

利用自制的单频激光器获得近通讯波段正交振幅压缩态光场

利用自制的1.34 μm和0.67 μm双波长输出单频激光器作为泵浦源,泵浦基于PPKTP晶体的光学参量放大器,通过边带锁频技术将光学参量放大腔腔长锁定在激光频率上,将泵浦光和信号光相对相位锁定在π相位,经参量缩小过程获得低于散粒噪声极限约3 dB的正交振幅压缩光.压缩光位于光纤通信窗口——1.3 μm波段.     

Frequency stabilization of a single-frequency all-solid-state laser for Doppler wind lidar

The master laser of an injection-seeded laser for Doppler wind lidar is frequency stabilized to a FabryPerot (FP) cavity using Pound-Drever-Hall technique. The FP cavity is specially designed to gain high temperature stability with Zerodur cavity and spacer. A computer based controller is used to sample and process the error signal. After the master laser is locked, the relative frequency drift is±25 kHz in 1 s,and ±55 kHz in 1 h, which can satisfy the need of Doppler wind lidar.     

Bottle microresonator with actively stabilized evanescent coupling

The evanescent coupling of light between a whispering-gallery-mode bottle microresonator and a subwavelength-diameter coupling fiber is actively stabilized by means of the Pound-Drever-Hall technique. We demonstrate the stabilization of a critically coupled resonator with a control bandwidth of 0.1?Hz, yielding a residual transmission of (9±3)×10(-3) for more than an hour. Simultaneously, the frequency of the resonator mode is actively stabilized.     

Improving Locking Accuracy of Resonant Optical Gyroscope by Laser and Acoustooptic Frequency Shifter Jointed Pound-Drever-Hall Technique

ABSTRACT

A laser and acoustooptic frequency shifter jointed Pound-Drever-Hall technique is designed to lock the resonant optical gyroscope. Utilizing direct digital synthesizer (DDS) technology and temperature control in the driver, the frequency-shift precision of the acoustooptic frequency shifter higher than 1 Hz is obtained. Experiments show that compared with locking by tuning the laser only, the zero-bias stability of the gyroscope is improved. In this locking scheme, there are few additional devices, the tuning of the laser and the acoustooptic frequency shifter share a common Pound-Drever-Hall locking system, and the demodulation and the locking algorithms are simple.     

Frequency stabilization of a Q-switched Nd:YAG laser oscillator with stability better 300 kHz following an rf-sideband scheme

A frequency stabilization scheme following the Pound-Drever-Hall technique modified with a sample and hold circuit has been applied to a Q-switched diode-pumped Nd:YAG ring oscillator. The high-power ring is injection seeded by a monolithic non-planar ring laser oscillator (NPRO). The slave oscillator emits pulses of 23 ns duration and 20 mJ pulse energy with almost diffraction limited beam quality (M² = 1.2) at a repetition rate of 400 Hz. The short-term fluctuation of the center frequency from pulse to pulse is 290 kHz. The oscillator is designed for applications within lidar measurements.     

Reduce of the Linewidth of a Diode Laser by Locking to a High-Finesse Fabry-Perot Cavity

We report frequency locking of a commercial 657nm diode laser to a high finesse Fabry-Perot cavity by the_ Pound-Drever-Hall method. The laser linewidth relative to the cavity is estimated to be about 6 kHz.     

Stable diode lasers for hydrogen precision spectroscopy

We report on an external cavity diode laser at 972 nmstabilized to a mid-plane mounted Fabry-Perot (FP) resonator with afinesse of 400000. The 0.5 Hz optical beat note line width betweentwo similar lasers (Allan deviation 2 × 10^-15) is limitedby thermal noise properties of two independent FP resonators. Thelong term drift of the FP resonator and mirror substrates made fromUltra-Low-Expansion glass (ULE) is small and can be well predictedon time intervals up to many hours if the resonator is stabilized atthe zero thermal expansion temperature T_c. Using a Peltierelement in a vacuum chamber for temperature stabilization allowsstabilization of the FP cavity to T_c which is usually below theroom temperature. Beat note measurements with a femtosecond opticalfrequency comb referenced to a H-maser during 15 hours have shown awell defined linear drift of the FP resonance frequency of about 60 mHz/s with residual frequency excursions of less than ±20 Hz.     

Spectral filtering of dual lasers with a high-finesse length-tunable cavity for rubidium atom Rydberg excitation

We propose and demonstrate an alternative method for spectral filtering and frequency stabilization of both 780-nm and 960-nm lasers using a high-finesse length-tunable cavity(HFLTC). Firstly, the length of HFLTC is stabilized to a commercial frequency reference. Then, the two lasers are locked to this HFLTC using the Pound–Drever–Hall(PDH) method which can narrow the linewidths and stabilize the frequencies of both lasers simultaneously. Finally, the transmitted lasers of HFLTC with each power up to about 100 μW, which act as seed lasers, are amplified using the injection locking method for single-atom Rydberg excitation. The linewidths of obtained lasers are narrowed to be less than 1 k Hz, meanwhile the obtained lasers' phase noise around 750 k Hz are suppressed about 30 d B. With the spectrally filtered lasers, we demonstrate a Rabi oscillation between the ground state and Rydberg state of single-atoms in an optical trap tweezer with a decay time of(67 ± 37) μs, which is almost not affected by laser phase noise. We found that the maximum short-term laser frequency fluctuation of a single excitation lasers is at ～ 3.3 k Hz and the maximum long-term laser frequency drift of a single laser is ～ 46 k Hz during one month. Our work develops a stable and repeatable method to provide multiple laser sources of ultra-low phase noise, narrow linewidth, and excellent frequency stability, which is essential for high precision atomic experiments, such as neutral atom quantum computing, quantum simulation, quantum metrology, and so on.     

Demonstration of a passive subpicostrain fiber strain sensor

We demonstrate a fiber Fabry-Perot (FFP) sensor that is capable of detecting subpicostrain signals, from 100 Hz and extending beyond 100 kHz, using the Pound-Drever-Hall (PDH) frequency locking technique. A low-power diode laser at 1550 nm is locked to a free-space reference cavity to suppress its free-running frequency noise, thereby stabilizing the laser. The stabilized laser is then used to interrogate a FFP sensor whose PDH error signal yields the instantaneous fiber strain.     

用乙炔稳频二极管-泵浦Er-Yb玻璃激光器

介绍了一种新颖的二极管-泵浦Er-Yb玻璃激光器，利用Pound-Drever-Hall技术并采用乙炔分子P（15）线对其实现了稳频。实验装置中将两个激光器的出射波长锁定到同一气室的乙炔P（15）吸收曲线的同一侧，使得温度对吸收峰值频率产生的漂移和温度导致气压变化使线宽增宽均对频率稳定性不产生影响。通过测量两个相同激光器系统间出射光波的拍频发现，激光的短期带宽窄于50kHZ，通过频率波动情况得出激光器有较高的相对频率稳定度。改进后的激光器稳定性和重复性显著提高，适合于实现高精度的光学频率标准。     

Stable Narrow Linewidth 689nm Diode Laser for the Second Stage Cooling and Trapping of Strontium Atoms

We report stable narrow linewidth laser systems based on self-developed Littman configuration external cavity diode lasers （ECDLs）. The frequency of the ECDL is stabilized to a high fineness ultralow-expansion glass reference cavity with the Pound-Drever-Hall technique. By heterodyne beating of two identical systems, we conclude that the linewidth 4.3× 10^-14 at an averaging measurement time. of each ECDL is reduced to lower than 150 Hz and its frequency stability reaches time of 1 s, the averaged long-term frequency drift is less than 0.2 Hz/s over 30 h