共查询到20条相似文献,搜索用时 15 毫秒
1.
A. V. Zhukov I. O. Zolotovskii O. G. Okhotnikov D. I. Sementsov A. A. Sysolyatin I. O. Yavtushenko 《Optics and Spectroscopy》2012,113(1):75-80
Conditions of the formation and amplification of frequency-modulated soliton-like pulses in longitudinally inhomogeneous active optical waveguides with anomalous dispersion of group velocities are studied. Group velocity dispersion profiles that are necessary for existence and amplification for active and passive optical waveguides are determined, and the dependences on the distance passed along the waveguide, duration, and chirp of the pulse are established. 相似文献
2.
I. O. Zolotovskii V. A. Lapin D. I. Sementsov D. A. Stolyarov 《Optics and Spectroscopy》2017,122(3):475-481
The conditions for the generation and efficient amplification of frequency-modulated soliton-like wave packets in longitudinally inhomogeneous active optical waveguides have been studied. The possibility of forming a sequence of pico- and subpicosecond pulses from quasi-continuous radiation in active and passive optical waveguides with the group-velocity dispersion (GVD) changing over the waveguide length is considered. The behavior of a wave packet in the well-developed phase of modulation instability with a change in the waveguide inhomogeneity parameters has been investigated based on the numerical analysis. 相似文献
3.
A. S. Abramov I. O. Zolotovskii D. I. Sementsov D. A. Stolyarov 《Optics and Spectroscopy》2014,117(5):792-798
Specific features of the formation of frequency-modulated pulses with large peak powers in amplifier-modulator-compressor cascade schemes based on length-inhomogeneous optic fibers are considered. Optimum profiles of fiber parameters ensuring the most effective amplification and modulation of pico- and subpicosecond frequency-modulated pulses are proposed. It is established that the use of a cascade consisting of active (gain) and passive (modulating) fibers with optimized profiles of the normal group-velocity dispersion and mode area can ensure the formation of pico- and subpicosecond pulses with energies higher than 100 nJ and peak powers above 100 kW. 相似文献
4.
I. O. Zolotovskii D. A. Korobko O. G. Okhotnikov D. I. Sementsov A. A. Sysoliatin A. A. Fotiadi 《Optics and Spectroscopy》2013,114(2):260-265
The possibility of efficient amplification of self-similar frequency-modulated wave packets in amplifiers inhomogeneous along their length is investigated. Special features of the amplification dynamics in erbium fiber amplifiers that operate according to the three-level scheme are analyzed. It is shown that active optical fibers with a specially designed profile of the normal group-velocity dispersion allow amplifying subpicosecond pulses with high efficiency. 相似文献
5.
The effect of the second-order dispersion on the spatiotemporal dynamics of ultrashort pulses in nonlinear waveguides with infinite parabolic and stepped profiles of the refractive index is studied. It is shown that the leakage of radiation from the core to the cladding of step-index waveguides prevents the formation of a steady spatiotemporal distribution of the field. The possibility of compressing light pulses in a dielectric waveguide with a positive group-velocity dispersion is discussed. 相似文献
6.
Chowdhury Debasruti Bose Navonil Ghosh Dipankar Basu Mousumi 《Optical and Quantum Electronics》2017,49(9):1-12
Optical and Quantum Electronics - The nonlinear scattering of two non-collinear Gaussian pulses with different central frequencies and lengths, incident on the periodic stacks of semiconductor... 相似文献
7.
A. A. Zabolotskii 《Journal of Experimental and Theoretical Physics》2002,94(5):869-881
The dynamics of pulses with durations comparable to the inverse transition frequency that propagate in an optical medium is studied in terms of two integrable systems of Maxwell-Bloch equations. The first model describes the field interaction with a nondegenerate medium with a permanent dipole moment and permanent external pumping. A general formula is derived for the N-soliton solution. Particular solutions are used as examples to investigate the effect of permanent dipole moment and pumping on the soliton dynamics. The second model describes the interaction between two-component electric-field pulses and a two-level degenerate medium with permanent upper-level pumping. For different initial magnetic-sublevel populations, soliton solutions are used as examples to show that pumping causes a change in polarization dynamics. A two-soliton solution is used to analyze the interaction of solitons in a two-level medium with external pumping. 相似文献
8.
We propose a unified theory to construct exact rogue wave solutions of the (2+1)-dimensional nonlinear Schrdinger equation with varying coefficients. And then the dynamics of the first- and the second-order optical rogues are investigated. Finally, the controllability of the optical rogue propagating in inhomogeneous nonlinear waveguides is discussed. By properly choosing the distributed coefficients, we demonstrate analytically that rogue waves can be restrained or even be annihilated, or emerge periodically and sustain forever. We also figure out the center-of-mass motion of the rogue waves. 相似文献
9.
L. Mashev 《Applied Physics A: Materials Science & Processing》1978,17(2):189-192
A method to compute the propagating modes of graded index waveguides with an arbitrary refractive index distribution is proposed,
based on the variational method applied to the integral wave equation. The method is applied to two refractive index distributions:
a Gaussian index distribution and a complementary error-function index distribution. The results are compared with the predictions
of perturbation analysis and are experimentally verified by measuring the mode spectrum of a Ti-diffused LiNbO3 waveguide. 相似文献
10.
11.
The possibility of ideal soliton amplification in a waveguide due to the formation of a specific inhomogeneity of its radius along the length is studied using the example of an active gradient-index (with a parabolic profile of the refractive index) optical fiber. It is shown that, in the case of an appropriate choice of the a(z) function, such soliton dynamics is possible even if the gain increment is constant over the length. The conditions imposed on the frequency dependences of the parameters determining the soliton dynamics are considered. 相似文献
12.
The conditions for forming pulses with parabolic envelope asymptotics in inhomogeneous fiber optical amplifiers are investigated. The profile of normal group-velocity dispersion, which ensures formation of parabolic pulses with a reduced rate of frequency modulation, is determined. It is shown by numerical simulation that the presence of chirp in the input pulse may cause narrowing of the spectrum at a certain energy. 相似文献
13.
This paper presents an analysis of the performance of frequency-modulated pulses and of pulses modulated simultaneously in amplitude and frequency in the pure nuclear quadrupolar resonance (NQR) spectroscopy of spin 3/2 nuclei. Computer simulations are given of the offset compensation efficiency of such pulses as applied to single crystals. Spin evolution equations were solved numerically. Experimental measurements, using FM pulses, of the35Cl NQR of sodium chlorate (NaClO3) single crystal and of mercuric chloride (HgCl2) powder are reported. The results suggest that frequency modulated pulses are alternative pulses to composite pulses in NQR. 相似文献
14.
A. V. Gureev 《Radiophysics and Quantum Electronics》1990,33(8):701-709
Institute of Electronic Technology, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 33, No. 8, pp. 954–964, August, 1990. 相似文献
15.
Yu. V. Kistenev 《Russian Physics Journal》1994,37(8):780-783
This study predicts the manifestation of anisotropic properties in linearly isotropic inhomogeneous resonant media during the propagation of optical pulses through them with pulse durations comparable to the phase memory of the medium. For examples, the energy of an obliquely incident pulse propagating through a layered inhomogeneous medium, varies with inversion of the propagation direction. This effect results from phase modulation of the pulse duse to variation in refraction in a region of transient coherent processes in the medium. This study analyzes the most favorable conditions for observing anisotropic effects.V. D. Kuznetsov Siberian Physical — Technical Institute, Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 96–99, August, 1994. 相似文献
16.
17.
A. A. Zabolotskii 《Journal of Experimental and Theoretical Physics》2012,114(5):699-706
The propagation of the coupled state of the electron density perturbation in an extended metallic medium and the excitation of a two-level resonant medium are analyzed. The one- and two-photon transitions in the resonant medium are considered. The electron density perturbation is described using the hydrodynamic approximation. The formation of plasmon-polariton pulses is analyzed in the case when losses in the extended medium are compensated for by the pumping of the two-level dielectric medium. Numerical analysis carried out for the two models revealed that the losses in a soliton-like pulse in a thin metallic medium can be compensated for due to the energy transfer from the amplifying medium to electron density waves. It is shown that the dispersion of a medium containing a two-level component may considerably affect the characteristics of the pulses. The possibility of effectively controlling the evolution of soliton-like pulses by varying an external electromagnetic field and the characteristics of the matrix is demonstrated. 相似文献
18.
Fabrication of microfluidic optical waveguides on glass chips with femtosecond laser pulses 总被引:1,自引:0,他引:1
We describe the fabrication of microfluidic channel structures on the surface of a borosilicate glass slide by femtosecond laser direct writing for optical waveguide application. Liquid with a variable refractive index is fed into the microchannel, serving as the core of the waveguide. We demonstrate that either a multimode or a single-mode waveguide can be achieved by controlling the refractive index of the liquid. 相似文献
19.
Samsonov SV Phelps AD Bratman VL Burt G Denisov GG Cross AW Ronald K He W Yin H 《Physical review letters》2004,92(11):118301
A new method to generate ultrahigh-power microwave pulses compatible with mildly relativistic electron sources is proposed. This method involves a novel microwave compressor in the form of a metal helically corrugated waveguide, which can enhance the power of frequency-modulated nanosecond pulses up to the multigigawatt level. The results of the proof-of-principle experiments at kilowatt power levels are in good agreement with theory. 相似文献
20.
Solitary optical waves with characteristic red frequency shift have been numerically identified in fibers with positive group
velocity dispersion in the presence of amplification by semiconductor amplifiers. Influence of the Henry factor, the net gain,
gain saturation characteristics, and frequency modulation on the frequency shift of the observed solitary optical waves has
been examined. Normalized pulse energy as a function of the gain saturation characteristics has been studied.
相似文献