共查询到17条相似文献,搜索用时 203 毫秒
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飞秒光学频率梳波长覆盖范围向可见光波长扩展对于碘稳频激光的绝对频率测量以及光钟研究中钟激光的绝对频率测量都具有十分重要的意义. 本文在自行研制掺Er光纤飞秒光学频率梳的基础上, 采用放大-倍频-扩谱的方案, 实现了激光输出波长向可见光波长的扩展. 掺Er光纤飞秒光学频率梳输出的一部分光激光脉冲, 功率约为8 mW, 首先经掺Er光纤放大器将功率提高到531 mW, 此后利用MgO: PPLN晶体倍频, 倍频后激光的功率为170 mW, 倍频效率为32%, 脉冲宽度为85 fs. 倍频后的激光通过光子晶体光纤进行光谱展宽. 通过优化入射光偏振状态可以实现波长覆盖500-1000 nm, 输出功率为85 mW, 耦合效率为50%. 采用小型化碘稳频532 nm Nd: YAG激光器输出激光与光学频率梳光谱展宽后的激光进行拍频可以获得30 dB的拍频信号. 覆盖可见光波长的掺Er光纤飞秒光学频率梳为可见光范围内激光的绝对频率测量提供了技术手段. 相似文献
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V.V. Anisovich A.V. Sarantsev 《The European Physical Journal A - Hadrons and Nuclei》2003,16(2):229-258
We present the results of the current analysis of the partial wave IJ
PC = 00+ + based on the available data for meson spectra ( ππ, KˉK,ηη,η,ππππ). In the framework of the K-matrix approach, the analytical amplitude has been reconstructed in the mass region 280 MeV < < 1900 MeV. The following scalar-isoscalar states are seen: comparatively narrow resonances f
0(980), f
0(1300), f
0(1500), f
0(1750) and the broad state f0(1200-1600). The positions of the amplitude poles (masses and total widths of the resonances) are determined as well as pole
residues (partial widths to meson channels ππ, KˉK,ηη,η,ππππ). The fitted amplitude gives us the positions of the K-matrix poles (bare states) and the values of bare-state couplings to meson channels thus allowing the quark-antiquark nonet
classification of bare states. On the basis of the obtained partial widths to the channels ππ, KˉK,ηη,η, we estimate the quark/gluonium content of f
0(980), f
0(1300), f
0(1500), f
0(1750), f0(1200-1600). For f
0(980), f
0(1300), f
0(1500) and f
0(1750), their partial widths testify the qˉq origin of these mesons though being unable to provide precise evaluation of the possible admixture of the gluonium component
in these resonances. The ratios of the decay coupling constants for the f0(1200-1600) support the idea about the gluonium nature of this broad state.
Received: 14 May 2002 / Accepted: 20 August 2002 / Published online: 11 February 2003
RID="a"
ID="a"e-mail: anisovic@thd.pnpi.spb.ru
Communicated by A. Sch?fer 相似文献
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实验利用商品光纤飞秒激光器,自行构建了一套完整的光学频率梳系统,并获得了约30 dB信噪比的系统频移(fceo)信号.实现了光频梳重复频率(frep)信号及系统频移(fceo)信号的高稳定度锁定,并通过实验验证了光频梳锁定的跟踪精度.基于此稳定光频梳完成了对1064 nm碘稳频Nd:YAG固体激光器的绝对频率测量.实验结果表明,frep的跟踪精度在100 s取样时间时优于3.7×10-14,测量得到的1064 nm激光器绝对频率为:281630111757362 Hz.这一测量结果与国际计量委员会(CIPM)给出的国际推荐值符合到不确定度之内.
关键词:
光纤光频梳
稳频
锁相技术
光学频率计量 相似文献
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E.L. Bratkovskaya W. Cassing L.A. Kondratyuk A. Sibirtsev 《The European Physical Journal A - Hadrons and Nuclei》1999,4(2):165-170
Within the meson-exchange model we calculate f
0-meson production cross section in πN and NN reactions and investigate the possibility for f
0 observation via the KˉK decay mode in pp collisions. Our studies indicate that an extraction of the f
0 signal is unlikely due to the large background from other reaction channels.
Received: 14 October 1998 / Revised version: 17 November 1998 相似文献
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Recently, much research has indicated that more and more cancers pose a threat to human life. Cancers are caused by oncogenes. Many human oncogenes have been found and most of them are located on chromosomes. The discovery of the oncogene plays a significant role in the treatment of cancer. The p53 tumor suppressor gene has received much attention because it frequently mutates or deletes in tumor cells of most people. Thus, the study of oncogenes is significant. In order to establish the Galois field (GF(7)), the indefinite gene is introduced as D and oncogene is introduced as O, and P. Taking the polynomial coefficients a0, a1, a2 ∈ GF(7) and the bijective function f:GF(7) → {D,A,C,O,G,T,P}, where f(0) = D, f(1) = A, f(2) = C, f(3) = O, f(4) = G, f(5) = T, and f(6) = P, the bijective φ may be written as φ(a0 + a1x + a2x2). Based on the algebraic structure, we can not only analyse the DNA sequence of oncogenes, but also predict possible new cancers. 相似文献
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Precise determination of characteristic laser frequencies by an Er-doped fiber optical frequency comb 下载免费PDF全文
Shiying Cao 《中国物理 B》2022,31(7):74207-074207
Femtosecond optical frequency combs correlate the microwave and optical frequencies accurately and coherently. Therefore, any optical frequency in visible to near-infrared region can be directly traced to a microwave frequency. As a result, the length unit "meter" is directly related to the time unit "second". This paper validates the capability of the national wavelength standards based on a home-made Er-doped fiber femtosecond optical frequency comb to measure the laser frequencies ranging from visible to near-infrared region. Optical frequency conversion in the femtosecond optical frequency comb is achieved by combining spectral broadening in a highly nonlinear fiber with a single-point frequency-doubling scheme. The signal-to-noise ratio of the beat notes between the femtosecond optical frequency comb and the lasers at 633, 698, 729, 780, 1064, and 1542 nm is better than 30 dB. The frequency instability of the above lasers is evaluated by using a hydrogen clock signal with a instability of better than 1×10-13 at 1-s averaging time. The measurement is further validated by measuring the absolute optical frequency of an iodine-stabilized 532-nm laser and an acetylene-stabilized 1542-nm laser. The results are within the uncertainty range of the international recommended values. Our results demonstrate the accurate optical frequency measurement of lasers at different frequencies using the femtosecond optical frequency comb, which is not only important for the precise and accurate traceability and calibration of the laser frequencies, but also provides technical support for establishing the national wavelength standards based on the femtosecond optical frequency comb. 相似文献
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J.-h. Lee E. B. Kim T. T. Luu W.-K. Lee D.-H. Yu J. Park C. Y. Park T. J. Yu C. H. Nam 《Applied physics. B, Lasers and optics》2011,104(4):793-797
We analyzed frequency-domain characteristics of a femtosecond laser whose carrier-envelope phase (CEP) was stabilized by the
direct locking method (DLM). To evaluate the CEP-stabilized laser with zero carrier-envelope-offset frequency (f
ceo), as imposed by DLM, a self-referencing f-to-2f interferometer with a shifted frequency comb by an acousto-optic modulator was employed in an out-of-loop. The measurement
of the square root of triangle variance confirmed that DLM is a phase-locking method. The tight locking was verified from
a narrow bandwidth of f
ceo, measured using the out-of-loop interferometer, and from a small frequency jitter measured with a frequency counter referenced
to a Rb-clock. The femtosecond laser with CEP stabilized by DLM is, thus, well suited for applications in the frequency domain
as well as in the time domain. 相似文献
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Yoshiaki Nakajima Hajime Inaba Atsushi Onae Takao Kobayashi Hirokazu Matsumoto 《Optics Communications》2008,281(17):4484-4487
We report a method for optimizing the amplification of femtosecond optical pulses by using dispersion management. The amount of dispersion provided to the seed optical pulse of an erbium-doped fiber (EBF) has an optimal region that enhances the output power of an amplifier. The power enhancement is accompanied by spectral broadening, which originates from adiabatic narrowing in the erbium-doped fiber. The amplified optical pulses can be used to generate an octave-spanning optical frequency comb (OFC) by employing a highly nonlinear fiber (HNLF). 相似文献
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高重复频率掺Er光纤飞秒激光器在光学频率梳、超高速光学采样等领域具有很重要的作用. 本文采用非线性偏振旋转锁模机理, 在掺Er光纤飞秒激光器中实现了重复频率为303 MHz的锁模脉冲输出. 通过优化腔内色散, 激光器腔内色散在零色散附近偏负值, 锁模后工作在展宽脉冲锁模状态. 在817 mW抽运功率下, 激光器在连续光状态下可以输出125 mW的平均功率, 在锁模状态下可以输出69 mW的平均功率, 脉冲宽度为90 fs. 当抽运功率处于700-817 mW时, 激光器可以实现自启动锁模. 激光器重复频率在5 h内的漂移量为30 Hz. 相似文献