共查询到20条相似文献,搜索用时 99 毫秒
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共孔径元件是强激光发射光学系统极为重要的光学部件。本文研究了隐埋光栅型共孔径分光元件产生色散的机理,提出补偿色散的方法,并给出色散补偿设计实例。 相似文献
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双光栅快速扫描光学延迟线的色散补偿 总被引:1,自引:0,他引:1
光学相干层析成像(OCT)系统的纵向分辨力不仅与光源的带宽有关,而且与系统中两干涉臂间的色散匹配有关。如果色散没有得到精确匹配,将使光学相干层析成像系统的纵向分辨力达不到所预期的理论值。色散问题在超高分辨光学相干层析成像系统中尤为突出。提出了一种基于双光栅快速扫描光学延迟线(RSOD),用于光学相干层析成像系统的色散补偿。该方法中新增的光栅引入了光栅间距这一独立变量,其与常规单光栅快速扫描光学延迟线机构中的光栅离焦量一起,可使光学相干层析成像系统中的群速度色散(GVD)和三阶色散(TOD)同时得到补偿。分析了双光栅快速扫描光学延迟线的色散特性和色散调节原则,并提供了一个典型光学相干层析成像系统中的色散补偿实例。 相似文献
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We demonstrate that it is possible to perform a fractional Fourier transform of an incident pulse with a continuously variable degree of fractionality, using a dispersive and nonlinear Kerr medium. This medium acts as a linear waveguide for the optical pulse if its intensity is small and if the refractive index is nonlinearly time-dependently modified by a simultaneously launched bright soliton. For optical pulses the dispersive and nonlinear medium is perfectly equivalent to a graded-index refractive medium for optical beams. 相似文献
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Experimental study on the chirped structure of the white-light continuum generation by femtosecond laser spectroscopy 下载免费PDF全文
The chirped structure of the white-light continuum generation (WLCG) pulse produced by focusing 800nm laser pulse with a pulse duration of 150fs (FWHM: full-width-at-half-maximum) onto a 2.4 mm thick sapphire plate was investigated by the optical Kerr gate technique with normal hexane as the optical Kerr gate medium. The observed WLCG was positively chirped, the measured anti-Stokes spectrum of WLCG ranges from 449 to 580nm with a temporal span of 2.56ps. When using metal reflecting mirrors to eliminate the group velocity dispersion (GVD) effect, we found that a span of 1.3ps still remained, indicating that the chirped pulse cannot be accounted for simply by GVD of the pulse propagation in the dispersive media. Our results suggest that the light-induced refractive index change due to the third-order nonlinear optical effect leads to an additional positive group velocity dispersion, which contributes to an important portion of the observed temporal broadening of the chirped WLCG. In addition to using reflective optical elements instead of dispersive optical elements, an effective way of reducing the chirp is to minimize the optical path length of the WLCG medium. 相似文献
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By introducing an intracavity Doppler shift in a resonator with a highly dispersive nonlinear medium, a train of optical pulses is generated whose features are related to the slow/fast-light response of the medium. The cavity transmission is asymmetric and the pulse shape is modified differently depending on the direction of the Doppler shift, hence, on the sign of the group delay provided by the dispersive process. 相似文献
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The transformation of the envelope of a Gaussian pulse incident on and reflecting from a nonlinear dispersive medium is studied.
It is shown that the pulse envelope transforms considerably upon reflection near the optical resonance frequency and the nonlinearity
of the medium may appreciably distort the reflected pulse. Away from the resonance frequency, conditions may arise when the
shift of the reflected pulse does not lead to the loss of the Gaussian form. In this case, the influence of nonlinearity is
insignificant. 相似文献
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Optics and Spectroscopy - A theory of optical two-component pulse of self-induced transparency in a dispersive medium has been developed. Using the generalized version of the perturbative expansion... 相似文献
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Frequency-resolved optical gating is used to characterize the propagation of intense femtosecond pulses in a nonlinear, dispersive medium. The combined effects of diffraction, normal dispersion, and cubic nonlinearity lead to pulse splitting. The role of the phase of the input pulse is studied. The results are compared with the predictions of a three-dimensional nonlinear Schr?dinger equation. 相似文献
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O. I. Paseka V. E. Lobanov A. P. Sukhorukov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(12):1628-1631
A theory of compression of short optical pulses with quadratic phase modulation in a dispersive medium has been developed. The results of numerical simulation of the equation for the light wave field are reported. The conditions are found at which a pulse is compressed to one oscillation period. The optimal phase modulation index providing the maximum pulse compression is estimated. 相似文献
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《Comptes Rendus Physique》2009,10(10):1008-1013
A novel technique to produce large all-optically controlled tunable delays of 100 ps pulse train in optical fibers is demonstrated. The configuration of the delay line basically consists of two main stages: the wavelength conversion via semiconductor optical amplifiers and the group velocity delaying via a dispersive optical medium. The wavelength-converted signal was precisely delayed over a wide temporal range from picoseconds to nanoseconds using a dispersive fiber, preserving the wavelength and the bandwidth of the signal. 100 ps FWHM signal pulses were delayed continuously up to 14 ns with moderate pulse distortion, corresponding to a 140-bit delay. To cite this article: L. Thévenaz, S. Chin, C. R. Physique 10 (2009). 相似文献
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J.C. Delagnes A. Monmayrant P. Zahariev A. Arbouet B. Chatel B. Girard M.A. Bouchene 《Applied physics. B, Lasers and optics》2007,86(4):573-578
An ultra-short pulse propagating in a resonant dense atomic medium experiences an important distortion due to a strong modification
of its spectral phase. This distortion cannot be corrected using the usual simple dispersive devices (a pair of prisms, gratings,
etc.). We present here an experimental demonstration of the compensation of this effect using a dual 640-pixel high-resolution
pulse-shaper device. A cross-correlation intensity measurement combined with the XFROG (cross-correlated frequency-resolved
optical gating) spectral phase measurement of the compensated pulse are performed; efficient correction of the resonant dispersive
phase is shown. A spectacular temporal compression of the propagating pulse is then obtained.
PACS 92.60.Ta; 42.50.Md; 42.65.Re; 42.79.-e 相似文献