排序方式: 共有41条查询结果,搜索用时 253 毫秒
1.
The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment
of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and
the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation
factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this
model that does not use the general relativistic equations. The computed values presented in this paper compare well with
recent levels of accuracy of their respective experimental results. 相似文献
2.
J.N. Ames S. Ghosh R.S. Windeler A.L. Gaeta S.T. Cundiff 《Applied physics. B, Lasers and optics》2003,77(2-3):279-284
We observe that nanojoule femtosecond pulses that are spectrally broadened in a microstructured fiber acquire excess noise. The excess noise is manifested as an increase in the noise floor of the rf spectrum of the photocurrent from a photodetector illuminated by the pulse train from the laser oscillator. Measurements are made of the intensity dependence of the excess noise for both 100 fs and sub-10 fs pulses. The excess noise is very strong for 100 fs pulses, but barely measurable for sub-10 fs pulses. A rigorous quantum treatment of the nonlinear propagation of ultrashort pulses predicts that, for a fixed generated bandwidth, the amount of excess noise decreases with pulse duration, in agreement with the experimental results. 相似文献
3.
Soliton squeezing in microstructure fiber 总被引:4,自引:0,他引:4
We demonstrate, for the first time to our knowledge, the generation of squeezed light by means of soliton self-phase modulation in microstructure fiber. We observe and characterize the formation of solitons in the microstructure fiber at 1550 nm. A maximum squeezing of 2.7 dB is observed, corresponding to 4.0 dB after correcting for detection losses. The dependence of this quantum-noise reduction on various system parameters is studied in detail. Features of the microstructure fiber can be exploited for generation of low-energy continuous-variable entangled pulses for use in all-fiber teleportation experiments. 相似文献
4.
The carrier-envelope phase of the pulse train emitted by a 10-fs mode-locked laser has been stabilized such that carrier-envelope phase coherence is maintained for at least 150 s (measurement limited). The phase coherence time was measured independently of the feedback loop. 相似文献
5.
We have developed an ultrahigh-resolution optical coherence tomographic system in which broadband continuum generation from a photonic crystal fiber is used to produce high longitudinal resolution. Longitudinal resolution of 1.3-microm has been achieved in a biological tissue by use of continuum light from 800 to 1400 nm. The system employed a dynamic-focusing tracking method to maintain high lateral resolution over a large imaging depth. Subcellular imaging is demonstrated. 相似文献
6.
Corwin KL Newbury NR Dudley JM Coen S Diddams SA Weber K Windeler RS 《Physical review letters》2003,90(11):113904
Broadband noise on supercontinuum spectra generated in microstructure fiber is shown to lead to amplitude fluctuations as large as 50% for certain input laser pulse parameters. We study this noise using both experimental measurements and numerical simulations with a generalized stochastic nonlinear Schr?dinger equation, finding good quantitative agreement over a range of input-pulse energies and chirp values. This noise is shown to arise from nonlinear amplification of two quantum noise inputs: the input-pulse shot noise and the spontaneous Raman scattering down the fiber. 相似文献
7.
Pulse compression of nanojoule pulses in the visible using microstructure optical fiber and dispersion compensation 总被引:2,自引:0,他引:2
S. Lakó J. Seres P. Apai J. Balázs R.S. Windeler R. Szipőcs 《Applied physics. B, Lasers and optics》2003,76(3):267-275
Experimental results on the pulse compression of 1-nJ, 150-fs pulses from a tunable, 76-MHz Ti:sapphire laser oscillator operating
at around 750 nm are reported. The length of the pulses can be compressed to nearly one tenth by applying a high-delta, single-mode
microstructured optical fiber exhibiting zero group-delay dispersion at 767 nm, and by a prism-pair/chirped-mirror compressor.
The experimental results are verified by theoretical investigations modeling the pulse propagation taking into account non-linear
self-phase modulation and fiber dispersion.
Received: 10 June 2002 / Revised version: 15 November 2002 / Published online: 12 February 2003
RID="*"
ID="*"Corresponding author. Fax: +36-1/375-4553, E-mail: szipoecs@sunserv.kfki.hu 相似文献
8.
Liu X Xu C Knox WH Chandalia JK Eggleton BJ Kosinski SG Windeler RS 《Optics letters》2001,26(6):358-360
We report a soliton self-frequency shift of more than 20% of the optical frequency in a tapered air-silica microstructure fiber that exhibits a widely flattened large anomalous dispersion in the near infrared. Remarkably, the large frequency shift was realized in a fiber of length as short as 15 cm, 2 orders of magnitude shorter than those reported previously with similar input pulse duration and pulse energies, owing to the small mode size and the large and uniform dispersion in the tapered fiber. By varying the power of the input pulses, we generated compressed sub-100-fs soliton pulses of ~1-nJ pulse energy tunable from 1.3 to 1.65 mum with greater than 60% conversion efficiency. 相似文献
9.
Ultrahigh-resolution optical coherence tomography using continuum generation in an air-silica microstructure optical fiber 总被引:14,自引:0,他引:14
Hartl I Li XD Chudoba C Ghanta RK Ko TH Fujimoto JG Ranka JK Windeler RS 《Optics letters》2001,26(9):608-610
We demonstrate ultrahigh-resolution optical coherence tomography (OCT) using continuum generation in an air-silica microstructure fiber as a low-coherence light source. A broadband OCT system was developed and imaging was performed with a bandwidth of 370 nm at a 1.3-mu;m center wavelength. Longitudinal resolutions of 2.5 microm in air and ~2 microm in tissue were achieved. Ultrahigh-resolution imaging in biological tissue in vivo was demonstrated. 相似文献
10.
Visible continuum generation in air-silica microstructure optical fibers with anomalous dispersion at 800 nm 总被引:26,自引:0,他引:26
We demonstrate experimentally for what is to our knowledge the first time that air-silica microstructure optical fibers can exhibit anomalous dispersion at visible wavelengths. We exploit this feature to generate an optical continuum 550 THz in width, extending from the violet to the infrared, by propagating pulses of 100-fs duration and kilowatt peak powers through a microstructure fiber near the zero-dispersion wavelength. 相似文献