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1.
Nonlinear photonic crystals made from polystyrene materials that have Kerr nonlinearity can exhibit ultrafast optical switching when the samples are pumped by ultrashort optical pulses with high intensity due to the change of the refractive index of polystyrene and subsequent shift of the band gap edge or defect state resonant frequency. Polystyrene has a large Kerr nonlinear susceptibility and almost instantaneous response to pump light, making it suitable for the realization of ultrafast optical switching with a response time as short as a few femtoseconds. In this paper, we review our experimental progress on the continual improvement of all-optical switching speed in two-dimensional and three-dimensional polystyrene nonlinear photonic crystals in the past years. Several relevant issues are discussed and analyzed, including different mechanisms for all-optical switching, preparation of nonlinear photonic crystal samples by means of microfabrication and self-assembly techniques, characterization of optical switching performance by means of femtosecond pump-probe technique, and different ways to lower the pump power of optical switching to facilitate practical applications in optical information processing. Finally, a brief summary and a perspective of future work are provided. 相似文献
2.
Ye Liu Fei Qin Fei Zhou Qing-bo Meng Dao-zhong Zhang Zhi-yuan Li 《Frontiers of Physics in China》2010,5(3):220-244
Nonlinear photonic crystals made from polystyrene materials that have Kerr nonlinearity can exhibit ultrafast optical switching
when the samples are pumped by ultrashort optical pulses with high intensity due to the change of the refractive index of
polystyrene and subsequent shift of the band gap edge or defect state resonant frequency. Polystyrene has a large Kerr nonlinear
susceptibility and almost instantaneous response to pump light, making it suitable for the realization of ultrafast optical
switching with a response time as short as a few femtoseconds. In this paper, we review our experimental progress on the continual
improvement of all-optical switching speed in two-dimensional and three-dimensional polystyrene nonlinear photonic crystals
in the past years. Several relevant issues are discussed and analyzed, including different mechanisms for all-optical switching,
preparation of nonlinear photonic crystal samples by means of microfabrication and self-assembly techniques, characterization
of optical switching performance by means of femtosecond pump-probe technique, and different ways to lower the pump power
of optical switching to facilitate practical applications in optical information processing. Finally, a brief summary and
a perspective of future work are provided. 相似文献
3.
R. A. Ganeev A. I. Ryasnyanskii Sh. R. Kamalov M. K. Kodirov T. Usmanov 《Technical Physics》2002,47(7):889-893
The Z-scan method is used to study the variation in the nonlinear susceptibility χ(3) (−gw; ω, ω, −ω) and nonlinear refractive index of colloidal silver with the degree of aggregation under the action of picosecond and nanosecond radiation (λ=1064 nm). The values of χ(3) for aggregated silver that are defined by Kerr nonlinearity and thermal self-focusing are found to be −1.5×10−14 and −4.4×10−11 esu, respectively. The time evolution of the picosecond pulses passing through the colloid is investigated. 相似文献
4.
《Photonics and Nanostructures》2014,12(1):83-92
Owing to the unique optical properties high-Q photonic crystal nanobeam microcavities have been demonstrated in a variety of materials. In this paper the design of high-Q silicon-polymer hybrid photonic crystal nanobeam microcavities is investigated using the three-dimensional plane-wave expansion method and finite-difference time-domain method. We first discuss the design of high-Q nanobeam microcavities in silicon-on-insulator, after which the polymer is introduced into the air void to form the hybrid structures. Quality factor as high as 1 × 104 has been obtained for our silicon-polymer hybrid nanobeam microcavities without exhaustive parameter examination. In addition the field distribution of resonant mode can be tuned to largely overlap with polymer materials. Because of the overwhelmingly large Kerr nonlinearity of polymer over silicon, the application in all-optical switching is presented by studying the shift of the resonant frequency on the change of refractive index of polymer. The minimum switching intensity of only 0.37 GW/cm2 is extracted for our high-Q hybrid microcavities and the corresponding single pulse energy is also discussed according to the pumping methods. The total switching time is expected to be restricted by the photon lifetime in cavity due to the ultrafast response speed of polymer. Our silicon-polymer hybrid nanobeam microcavities show great promise in constructing small-sized all-optical devices or circuits with advantages of possessing low-power and ultrafast speed simultaneously. 相似文献
5.
Photonic Crystal Circuits have been widely investigated for various optoelectronics device applications. And the gratings in photonics devices are indispensable tool, which is very common for light manipulation. In this study, an interference grating structure formed by Gaussian beam interferences in photonic crystal waveguide such that having Kerr type nonlinearity is proposed and its transmission characteristics are investigated. Finite-Difference Time-Domain method is used to analyze the device characteristics. According to simulation results, the interference grating has shown special transmission characteristics that can bring tunability for photonic crystal devices. This can be an effective method for controlling optical signals in the photonic crystal for all optical switching/routing applications as a part of add/drop multiplexing. 相似文献
6.
A method for measuring complex fast nonlinear optical nonlinearities χ
(3) in waveguides is demonstrated. It is based on a comparison between the optical nonlinearities of two different samples under
identical experimental circumstances and thus is independent of laser pulse parameters. Heterodyne detected four-wave mixing
is employed to achieve information about both amplitude and phase of χ
(3). To increase the sensitivity, a procedure for suppression of the limiting parasitic signals due to the photodiode nonlinearity
is suggested. Results obtained from a short piece of hollow-core photonic bandgap fiber are presented. 相似文献
7.
QND measurement schemes often use Kerr nonlinearity to couple the intensity fluctuations of the signal beam to the phase
fluctuations of the probe beam by means of the cross-phase modulation effect. Such schemes use materials with intrinsic χ(3)nonlinearity. However, it has already been shown that Kerr-effect-like correlation between two light waves may be achieved
through cascaded χ(2): χ(2) processes. The value of the nonlinearity induced by cascading χ(2) can, in many cases, be much higher than fibre χ(3).
The authors point out the possibility of using the cascaded χ(2) nonlinearity instead of intrinsic χ(3) nonlinearity in the scheme which resembles the well-known photon number QND measurement scheme. The non-degenerate second-harmonic
generation (SHG) with a large phase mismatch is considered. The harmonic wave influence on the measurements is shown. High
QND measurement characteristics can be achieved with the use of an appropriate set of parameters.
Received: 6 April 1996 相似文献
8.
LARGE AND EXTREMELY FAST THIRD-ORDER NON-LINEARITY OF Ag NANOPARTICLES EMBEDDED INTO A CsxO SEMICONDUCTOR MATRIX 下载免费PDF全文
Zhang Qi-feng Shao Qing-yi Hou Shi-min Zhang Geng-min Liu Wei-min Xue Zeng-quan Wu Jin-lei Wang Shu-feng Liang Rui-sheng Huang Wen-tao Wang Dan-ling Gong Qi-huang 《中国物理》2001,10(13):65-69
The third-order optical nonlinearity of Ag-O-Cs thin films, where Ag nanoparticles are embedded into a CsxO semiconductor matrix, was measured by the femtosecond optical Kerr technique. The third-order nonlinear optical susceptibility, χ(3), of the thin films was estimated to be 1.1×10-9 esu at the incident wavelength of 820 nm. The response time, i.e. the full width at half-maximum of the Kerr signal, is as fast as 114 fs only. The intrinsic third-order optical nonlinearity can be attributed to the intraband transition of electrons from the occupied state near the Fermi level to the unoccupied state. It is suggested that such a nonlinearity is further enhanced by the local field effect that is present in the metallic nanoparticles composite thin films. 相似文献
9.
10.
Large Kerr effect in bulk Se-based chalcogenide glasses 总被引:3,自引:0,他引:3
Lenz G Zimmermann J Katsufuji T Lines ME Hwang HY Spälter S Slusher RE Cheong SW Sanghera JS Aggarwal ID 《Optics letters》2000,25(4):254-256
High-speed optical communication requires ultrafast all-optical processing and switching capabilities. The Kerr nonlinearity, an ultrafast optical nonlinearity, is often used as the basic switching mechanism. A practical, small device that can be switched with ~1-pJ energies requires a large Kerr effect with minimal losses (both linear and nonlinear). We have investigated theoretically and experimentally a number of Se-based chalcogenide glasses. We have found a number of compounds with a Kerr nonlinearity hundreds of times larger than silica, making them excellent candidates for ultrafast all-optical devices. 相似文献
11.
STUDIES ON THE DYNAMICS OF OPTICAL BISTABILITY SWITCHING IN THE INTERNAL FABRY-PEROT CAVITY WITH A CdSxSe1-x-DOPED GLASS CHANNEL WAVEGUIDE 下载免费PDF全文
We report the optical bistability in CdSxSe1-x-doped glass channel waveguide with rise and fall times of about 24 and 30ps, respectively, in bistable switching by means of fiber coupling input with a power of about 3mW. The third-order nonlinear susceptibility (x(3)) of CdSxSe1-x-doped glass is estimated experimentally to be 1.8×10-9 esu. The high speed switching and the value of x(1) show that the optical bistability is caused by an optical nonlinearity which can be attributed to the band-filling effect. 相似文献
12.
The transfer matrix method was modified to explore the Kerr nonlinearity influence on laser radiation propagation in a one‐dimensional photonic crystal. The suggested spatial distribution of the refractive index allows to remove minibands and to make the transmission curve much steeper. Plain and steep photonic band gap edges are effective in creation of transmission anisotropy of powerful laser radiation. The investigated photonic crystal has a strong anisotropic optical transmission and acts as an optical analog of the electronic diode. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
N. Mattiucci G. D’Aguanno M. Scalora M. J. Bloemer 《Applied physics. B, Lasers and optics》2005,81(2-3):389-391
We present a numerical study of a finite photonic band gap structure with a χ(3) nonlinearity that couples two input pump beams at frequencies ω1 and ω2. We show that in this configuration a variety of all-optical devices can be obtained: an optical transistor, a double switch, and a dynamical switch. 相似文献
14.
Y. Liu D. Li R.Y. Zhu G.J. You S.X. Qian Y. Yang J.L. Shi 《Applied physics. B, Lasers and optics》2003,76(4):435-439
Au-core CdS-shell composite nanoparticles were synthesized by a direct self-assembly process and integrated into BaTiO3 thin films. Characterization by transmission electron microscopy showed that the average diameter of these composite nanoparticles
was about 8 nm. Using the femtosecond time-resolved optical Kerr effect method, we investigated the third-order nonlinear
optical response of the Au@CdS nanoparticles embedded in the BaTiO3 thin films at a wavelength of 800 nm. An ultrafast nonlinear response and a large effective third-order nonlinear susceptibility
of χ(3)=7.7×10-11 esu were observed. We attributed the enhancement of the third-order optical nonlinearity to a localized electric field effect
originating from the core-shell structure under off-surface-plasmon resonance conditions.
Received: 13 May 2002 / Revised version: 23 October 2002 / Published online: 3 April 2003
RID="*"
ID="*"Corresponding author. Fax: +86-21/6510-4949, E-mail: sxqian@fudan.ac.cn 相似文献
15.
Optical Kerr nonlinearity (n2) in n-type indium tin oxide (ITO) films coated on glass substrates has been measured using Z-scans with 200-fs laser pulses
at wavelengths ranging from 720 to 780 nm. The magnitudes of the measured nonlinearity in the ITO films were found to be dependent
on the carrier concentration with a maximum n2-value of 4.1×10-5 cm2/GW at 720-nm wavelength and an electron density of Nd=5.8×1020 cm-3. The Kerr nonlinearity was also observed to be varied with the laser wavelength. By employing a femtosecond time-resolved
optical Kerr effect (OKE) technique, the relaxation time of OKE in the ITO films is determined to be ∼1 ps. These findings
suggest that the Kerr nonlinearity in ITO can be tailored by controlling the carrier concentration, which should be highly
desirable in optoelectronic devices for ultrafast all-optical switching.
PACS 42.65.An; 42.65.Hw; 78.40.Fy 相似文献
16.
The “engineered” nonlinear nanocomposite materials with extremely large values of optical Kerr susceptibility and fast temporal responses that can be precisely tuned to satisfy the requirements of switching applications is of current interest in photonics. Metal quantum-dot composite glasses can exhibit enhanced optical susceptibility, χ(3), whose real and imaginary parts are related to the intensity-dependent refractive index and two-photon absorption coefficient, respectively. Classical (dielectric) and quantum confinement effects come into play in the nonlinear optical responses of these nanocomposites. Metal nanocluster-glass composites have been synthesized by 200 keV Cu+ and 1.5 MeV Au+ ion implantations in fused silica glasses at a dose of 3 × 1016 ions/cm2, followed by thermal annealing in reducing atmosphere to promote cluster growth. UV-Visible spectroscopy has revealed prominent linear absorption bands at characteristic surface plasmon resonance (SPR) frequencies signifying appreciable formation of copper and gold colloids in glass matrices. Third-order optical properties of the composite materials have been studied by Z-Scan and Anti-Resonant Interferometric Nonlinear Spectroscopy (ARINS) measurements. The sign of nonlinear refraction is readily obtained from the Z-Scan signatures. The ARINS technique utilizes the dressing of two unequal-intensity counter-propagating pulsed light beams with differential nonlinear phases, which occur upon traversing the sample if it exhibits nonlinear optical response. This difference in phase manifests itself in the intensity-dependent transmission. The nonlinear refractive index, nonlinear absorption coefficient, the real and imaginary parts of the third-order optical susceptibility have been extracted. 相似文献
17.
Ultrafast on‐Chip Remotely‐Triggered All‐Optical Switching Based on Epsilon‐Near‐Zero Nanocomposites
《Laser \u0026amp; Photonics Reviews》2017,11(5)
On‐chip‐triggered all‐optical switching is a key component of ultrahigh‐speed and ultrawide‐band information processing chips. 1 - 4 This switching technique, the operating states of which are triggered by a remote control light, paves the way for the realization of cascaded and complicated logic processing circuits and quantum solid chips. Here, a strategy is reported to realize on‐chip remotely‐triggered, ultralow‐power, ultrafast, and nanoscale all‐optical switching with high switching efficiency in integrated photonic circuits. It is based on control‐light induced dynamic modulation of the coupling properties of two remotely‐coupled silicon photonic crystal nanocavities, and extremely large optical nonlinearity enhancement associated with epsilon‐near‐zero multi‐component nanocomposite achieved through dispersion engineering. Compared with previous reports of on‐chip direct‐triggered all‐optical switching, the threshold control intensity, 560 kW/cm2, is reduced by four orders of magnitude, while maintaining ultrafast switching time of 15 ps. This not only provides a strategy to construct photonic materials with ultrafast and large third‐order nonlinearity, but also offers an on‐chip platform for the fundamental study of nonlinear optics. 相似文献
18.
We present first-principles calculations of the nonlinear optical (NLO) response of a Ni/Cu(001) bilayer. The calculations
are based on the full potential linearized augmented plane wave (FLAPW) method with the additional implementation of spin–orbit
coupling (SOC). On the basis of this set of eigenstates the magneto-optical transition-matrix elements are evaluated. Using
the surface-sheet model the optical reflection properties are determined for the cases of the magnetization vector perpendicular
to the surface (polar magneto-optical configuration (MOC)) and for the in-plane magnetization (longitudinal MOC). The nonlinear
optical susceptibility tensor elements χ(2)
ijk for different magnetization directions as well as the spectral dependence of χ(2)
ijk, the resulting intensities, and Kerr angles are presented for the Ni/Cu(001) bilayer. The results show that the magnetic
tensor elements of the χ(2)
ijk tensor are smaller than the nonmagnetic ones by only one order of magnitude, confirming the important role of magnetic properties
in the NLO response.
Received: 16 October 2001 / Revised version: 8 March 2002 / Published online: 29 May 2002 相似文献
19.
Tingyin Ning Cong Chen Yueliang Zhou Heng Lu Dongxiang Zhang Hai Ming Guozhen Yang 《Applied Physics A: Materials Science & Processing》2009,94(3):567-570
CaCu3Ti4O12 (CCTO) thin films were successfully prepared on LaAlO3 substrates by pulsed laser deposition technique. We measured the nonlinear optical susceptibility of the thin films using
Z-scan method at a wavelength of 532 nm with pulse durations of 25 ps and 7 ns. The large values of the third-order nonlinear
optical susceptibility, χ
(3), of the CCTO film were obtained to be 2.79×10−8 esu and 3.30×10−6 esu in picosecond and nanosecond time regimes, respectively, which are among the best results of some representative nonlinear
optical materials. The origin of optical nonlinearity of CCTO films was discussed. The results indicate that the CCTO films
on LaAlO3 substrates are promising candidate materials for applications in nonlinear optical devices. 相似文献