共查询到20条相似文献,搜索用时 46 毫秒
1.
B. Lal P. Aghamkar S. Kumar M. K. Kashyap 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(3):717-724
A detailed analytical investigation of second-order optical susceptibility has been made in moderately doped III-V weakly
piezoelectric semiconductor crystal, viz. n-InSb, in the absence and presence of an external magnetostatic field, using the
coupled mode theory. The second-order optical susceptibility arises from the nonlinear interaction of a pump beam with
internally generated density and acoustic perturbations. The effect of doping concentration, magnetostatic field and pump
intensity on second-order optical susceptibility of III-V semiconductors has been studied in detail. The numerical
estimates are made for n-type InSb crystals duly shined by pulsed 10.6 μm CO2 laser and efforts are
made towards optimising the doping level, applied magnetostatic field and pump intensity to achieve a large value of
second-order optical susceptibility and change of its sign. The enhancement in magnitude and change of sign of second-order
optical susceptibility, in weakly piezoelectric III-V semiconductor under proper selection of doping concentration and
externally applied magnetostatic field, confirms the chosen nonlinear medium as a potential candidate material for the
fabrication of nonlinear optical devices. In particular, at B
0 = 14.1 T, the second-order susceptibility was found to be
3.4 × 10-7 (SI unit) near the resonance condition. 相似文献
2.
Bin Yang Hengzhi Chen Mingfu Zhang Feiyan Wang Kokwai Cheah Wenwu Cao 《Applied Physics A: Materials Science & Processing》2009,96(4):1017-1021
Bi3TiNbO9 (BTN) thin films with layered perovskite structure were fabricated on fused silica by pulsed laser deposition. The XRD pattern
revealed that the films are single-phase perovskite and highly (00l) textured. Their fundamental optical constants, such as band gap, linear refractive index, and linear absorption coefficient,
were obtained by optical transmittance measurements. The dispersion relation of the refractive index vs. wavelength follows
the single electronic oscillator model. The nonlinear optical absorption of the films was investigated by single beam Z-scan
method at a wavelength of 800 nm with laser duration of 80 fs. We obtained the nonlinear absorption coefficient β=1.44×10−7 m/W. The results show that the BTN thin films are promising for applications in absorbing-type optical devices. 相似文献
3.
K. Milanchian E. Abdi H. Tajalli S. Ahmadi K. M.S. Zakerhamidi 《Optics Communications》2012,285(5):761-765
Third order nonlinear refractive index of three anthraquinone dyes, i.e., Solvent Blue 59, Solvent Blue 35 and Solvent Green 3 doped in 1294-1b nematic liquid crystal (NLC) were studied by the single beam Z-scan technique using a continuous-wave He–Ne laser at 632.8 nm. The negative nonlinear refractive index (n2) in the order of 10? 5 cm2/w for all samples was obtained. We believe that, this large nonlinearity is owing to Janossy effect and the difference in the nonlinear refractive index of our dyes can be described by the structures of dyes and the interactions between dyes and 1294-1b molecules. So as to understand the effect of dye structure on nonlinearity enhancement, the dichroic ratio of these dyes in 1294-1b was measured using polarized spectroscopy. 相似文献
4.
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
5.
Xin Chen Jun Tao Gang Zou Qijin Zhang Pei Wang 《Applied Physics A: Materials Science & Processing》2010,100(1):223-230
Diacetylene monomer containing p-nitrophenyl azobenzene moiety (NADA) was synthesized. Silver nanoparticles with different
concentrations were adulterated in the above polymerized NADA (PNADA) films and the third-order nonlinear optical properties
were investigated in detail. UV–vis spectra and transmission electron microscopy were used to confirm the formation of PNADA/Ag
nanocomposite films. The silver nanoparticles (average size of 10 nm) were well dispersed in the polymer films. The value
of the nonlinear refractive index n
2 for PNADA films (8.48×10−15 cm2/W) was much higher than that of pure polydiacetylene films. Further, the introduction of silver nanoparticles into the PNADA
polymer films led to the further enhancement of nonlinear optical properties. The maximum value of n
2 for PNADA/Ag nanocomposite films could be 11.6×10−15 cm2/W. This enhancement should be ascribed to the surface plasmon resonance of silver nanoparticles. 相似文献
6.
Investigation of third-order nonlinear optical properties of NNDC-doped PMMA thin films by Z-scan technique 总被引:1,自引:0,他引:1
Jingwei Chen Xinqiang Wang Quan Ren P. S. Patil Tingbin Li Hongliang Yang Jingnan Zhang Guochao Li Luyi Zhu 《Applied Physics A: Materials Science & Processing》2011,105(3):723-731
A novel chalcone derivative, (2E)-1-(2,4-di- chloro-5-fluorophenyl)-3-[4-dimethylamino)phenyl]prop-2-en-1-one, abbreviated as NNDC, was prepared and characterized
by elemental analyses, infrared (IR) and proton nuclear magnetic resonance (1H NMR) spectrum, and thermal analyses. The NNDC-doped poly(methyl methacrylate) (PMMA) thin films with five different doping
concentrations by weight were prepared by using a spin-coating method. Their linear optical properties were investigated by
using a prism coupling measuring system. The third-order nonlinear optical properties of NNDC in 1,2-dichloroethane (NNDC/1,2-dichloroethane)
solution and NNDC-doped PMMA (NNDC/PMMA) films were investigated by using the laser Z-scan technique with 20 ps pulses at
532 nm. A self-focusing effect was observed from the Z-scan curves for solution and thin films and the nonlinear refractive
index of the film increases with the increase of the doping concentration. In addition, nonlinear absorption was negligible
for all samples. The magnitude of third-order nonlinear refraction index n
2 and the third-order nonlinear susceptibility χ
(3) for thin films were 10−15 m2/W and 10−9 esu, respectively, which are about three orders larger than that of NNDC/1,2-dichloroethane solution. Some necessary analyses
were presented. The results show that this material is a promising candidate for application in the nonlinear optical devices
at 532 nm. 相似文献
7.
M.H. Majles Ara S.H. Mousavi E. Koushki S. Salmani A. Gharibi A. Ghanadzadeh 《Journal of Molecular Liquids》2008,142(1-3):29-31
The nonlinear optical properties of a nematic liquid crystal doped with an azo dye were investigated. The magnitude and the sign of the third-order nonlinear refractive index, n2, were measured using both single-beam z-scan and moiré deflectometry techniques. The measurements were performed at 532 nm using a Nd:Yag CW laser. The positive sign showed that sample which was studied possess a self-focusing optical nonlinearity. Rather close agreement was found between the values for n2 obtained by z-scan and by moiré deflectometry. The nonlinear refractive index was found to be in the order of 10− 6 (cm2/W) and the nonlinear absorption coefficient to be β = 0.171 (cm/W). 相似文献
8.
A master oscillator power amplifier (MOPA) system in which the output from an end-pumped Nd:YAG oscillator cavity dumped at
500 kHz is scaled up by a four-stage Nd:YVO4 amplifier is reported. Decrease in extraction efficiency of the amplifier chain with crystals different from that in the
oscillator was analyzed. With the 5.4 W seed output, 118 W of power was extracted from the amplifier chain at the pump power
of 345 W, with an extraction efficiency of 34.2% and an overall optical–optical efficiency of 30.9% for the MOPA system. The
beam quality factors were measured as M
x
2=1.45 and M
y
2=1.59 in two orthogonal directions, respectively. 相似文献
9.
We report the investigations of thermally induced third-order nonlinear optical and optical limiting characterizations for various concentrations of acid blue 40 dye in N,N-Dimethyl Formamide, studied by employing z-scan technique under cw He–Ne laser irradiation at 633 nm wavelength. The samples exhibited nonlinear absorption and nonlinear refraction under the experimental conditions. For lower concentration, the samples display both saturable absorption (SA) and reverse saturable absorption (RSA); whereas with increase in concentration, RSA behaviour prevails. The estimated values of the effective coefficients of nonlinear absorption βeff, nonlinear refraction n2 and third-order nonlinear susceptibility χ(3) were found to be of the order of 10?2 cm/W, 10?4 esu and 10?6 esu respectively. Multiple diffraction rings were observed when the samples were exposed to laser beam due to refractive index change and thermal lensing. The effect of concentration and the laser intensity on the self-diffraction ring patterns was studied experimentally. The acid blue 40 dye also exhibited strong optical limiting properties under cw excitation and reverse saturable absorption is found to be the dominant nonlinear optical process leading to the observed nonlinear behaviour. 相似文献
10.
C. G. Jin T. Yu Z. F. Wu F. Wang M. Z. Wu Y. Y. Wang Y. M. Yu L. J. Zhuge X. M. Wu 《Applied Physics A: Materials Science & Processing》2012,106(4):961-966
Al-doped zinc oxide (AZO) films are prepared on quartz substrates by dual-ion-beam sputtering deposition at room temperature
(∼25°C). An assisting argon ion beam (ion energy E
i
=0–300 eV) directly bombards the substrate surface to modify the properties of AZO films. The effects of assisted-ion beam
energy on the characteristics of AZO films were investigated in terms of X-ray diffraction, atomic force microscopy, Raman
spectra, Hall measurement and optical transmittance. With increasing assisting-ion beam bombardment, AZO films have a strong
improved crystalline quality and increased radiation damage such as oxygen vacancies and zinc interstitials. The lowest resistivity
of 4.9×10−3Ω cm and highest transmittance of above 85% in the visible region were obtained under the assisting-ion beam energy 200 eV.
It was found that the bandgap of AZO films increased from 3.37 to 3.59 eV when the assisting-ion beam energy increased from
0 to 300 eV. 相似文献
11.
U. Skrzypczak G. V. M. Williams M. Miclea M. D. H. Bhuiyan S. Janseens S. Schweizer 《Applied Physics A: Materials Science & Processing》2011,104(3):947-951
Single beam z-scan measurements have been made on films containing amorphous polycarbonate and the zwitterionic chromophore, PYR-3, that
has a very high second order nonlinear optical (NLO) figure of merit. The third order NLO figure of merit is ≈1.6 at 1030 nm
and is comparable to that found in organic compounds optimized for high n
2 values. The two-photon absorption coefficient is 2.1×10−12 m/W, which is very low and advantageous for NLO device applications. The third order NLO refractive index is −1.4×10−18 m2/W. 相似文献
12.
Y.H. Wang Y.M. Wang J.D. Lu L.L. Ji R.G. Zang R.W. Wang 《Physica B: Condensed Matter》2009,404(21):4295-4298
Metal nanocluster composite glass prepared by 180 keV Cu ions into silica with dose of 5×1016 ions/cm2 has been studied. The microstructural properties of the nanoclusters has been verified by optical absorption spectra and transmission electron microscopy (TEM). Third-order nonlinear optical properties of the nanoclusters were measured at 1064 and 532 nm excitations using Z-scan technique. The nonlinear refraction index, nonlinear absorption coefficient, and the real and imaginary parts of the third-order nonlinear susceptibility were deduced. Results of the investigation of nonlinear refraction by the off-axis Z-scan configuration were presented and the mechanisms responsible for the nonlinear response were discussed. Third-order nonlinear susceptibility χ(3) of this kind of sample was determined to be 8.7×10−8 esu at 532 nm and 6.0×10−8 esu at 1064 nm, respectively. 相似文献
13.
Guang Yang Aiping Chen Ming Fu Hua Long Peixiang Lu 《Applied Physics A: Materials Science & Processing》2011,104(1):171-175
By controlling the oxygen pressure, single-phase CuO and Cu2O thin films have been obtained on quartz substrates using a pulsed laser deposition technique. The structure properties and
linear optical absorption of the films were characterized by X-ray diffraction and UV–VIS spectroscopy. By performing z-scan measurements using a femtosecond laser (800 nm, 50 fs), the real and imaginary parts of the third-order nonlinear susceptibility,
Re χ
(3) and Im χ
(3), of the films were determined. Both CuO and Cu2O films exhibited large optical nonlinearities, which is comparable to those in some representative semiconductor films such
as ZnO and GaN films using femtosecond laser excitation. Compared with Cu2O films, the CuO films showed larger third-order nonlinear optical effects under off-resonance excitation. Furthermore, the
mechanisms of the optical nonlinearities in CuO and Cu2O films are explained in the main text. It was suggested that the reasons of the difference in their nonlinear refractive
effects may be related to the different electronic structure in CuO and Cu2O materials. 相似文献
14.
Jiangjiang Feng Xiaohui Li Tianci Feng Yamin Wang Jie Liu Han Zhang 《Annalen der Physik》2020,532(1):1900437
MXenes, as a legendary family of 2D van der Waals nanosheets materials, are extensively studied due to their unique characteristics of broadband nonlinear optical response. In particular, MXenes have excellent nonlinear optical properties of very large nonlinear absorption coefficients and very large nonlinear refractive indexes, which have attracted people's great attentions to study the application of MXenes in photonics, electronics, and optoelectronics in recent years. However, the high-repetition-rate (HRR) ultrafast pulses are not explored based on these kinds of materials. MXene Ti3C2Tx saturable absorber (SA) based on micro-fiber is fabricated by optical deposition method. Here, MXene Ti3C2Tx SA is used to achieve 36th harmonic mode-locking with a repetition rate of 218.4 MHz, a central wavelength of 1566.9 nm, the pulse width of 850 fs, and the spectral width of 3.51 nm. The maximum average output power and pulse energy are 6.95 mW and 0.032 nJ, respectively. This research based on MXene Ti3C2Tx light modulator opens a bright avenue for advanced nonlinear photonics. 相似文献
15.
Yan Chen Lunhua Deng Xuping Shao Jingxia Chen Yangqin Chen Xiaohua Yang 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(18):2208-2211
High resolution absorption spectra of the (4, 20) band in the second negative system (A2Πu–X2Πg) of O2+ cation were measured and analyzed in the range of 11 900–12 300 cm–1 via optical heterodyne velocity modulation spectroscopy. Precise molecular constants of the levels involved were obtained by a nonlinear least-squares fitting procedure combining with our previous spectra of the (4, 19) and (6, 20) bands. 相似文献
16.
S. Shojaei 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,83(2):197-201
The present work investigates the nonlinear optical properties of a GaN quantum dot in the disk limit via the exciton and
biexciton states using the compact density matrix formalism. Based on this model, we calculate the ground state energy of
the exciton and biexciton states by the variation method, within envelope function and effective mass approximations. Linear
and nonlinear optical absorption (α
(1), α
(3)) and oscillator strengths attributed to the optical transitions are obtained. The details of the behaviour of α
(1) and α
(3) around the resonance frequencies and for different quantum dot geometries are presented. It is found that the size of quantum
dot and the optical intensity have a remarkable effect on the optical absorption, and the biexcitonic two-photon absorption
coefficient(K
2) has also been calculated in this system. The results show that this parameter is strongly affected by the size of the quantum
dot. 相似文献
17.
《Current Applied Physics》2010,10(5):1290-1296
A chalcone single crystal, 1-(4-chlorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one that is transparent over the visible to infrared region is introduced as a new potential material to third-order nonlinear optical applications. The crystal exhibits ultrafast optical response (≤90 fs) and large optical nonlinearity in the wavelength range 800–1200 nm. A very large effective two-photon absorption coefficient βeff exceeding 120 cm/GW can be obtained with this chalcone crystal, at a low intensity threshold of 41 MW/cm2. The mechanism of nonlinear absorption at different levels of intensity has been discussed. The crystal shows no damage against the laser pulse intensity as high as 8 GW/cm2. We discuss the molecular and crystal designing of chalcones with large and ultrafast optical nonlinearity combined with low optical cut-off (<450 nm). 相似文献
18.
The nonlinear optical properties of Sudan I were investigated by a single beam Z-scan technique. The Sudan I ethanol solution exhibited large nonlinear refractive indices under both CW and pulse laser excitations. The nonlinear refractive indices of Sudan I were in the order of ?10?8 cm2/W under CW 633 nm excitation and ?10?6 cm2/W under CW 488 nm excitation, respectively. Under the excitation of a pulse 532 nm laser, the nonlinear refractive index n2 was calculated to be 1.19 × 10?14 cm2/W. It was discussed that the mechanism accounting for the process of nonlinear refraction was attributed to the laser heating for the CW laser excitation and the electronic effect for the pulse excitation. Moreover, the second hyperpolarizability of Sudan I was also estimated in this paper. 相似文献
19.
Shengwen Qi Chunping Zhang Xiuqin Yang Kuan Chen Lianshun Zhang Yongliang Liu Tang Xu Jianguo Tian 《Optik》2007,118(9):425-429
With the Z-scan method, the nonlinear optical properties of ethyl red (ER) in ethanol solution are measured by using the lasers of 441.6, 535 and 633 nm, respectively. As a result, the effective indexes of refraction n2 of CR at the three wavelengths are in the range from 10−10 to 10−9 m2 W−1. The nonlinear absorption of ER ethanol film at the three wavelengths is measured respectively. The self-diffraction of the ER solution at 441.6 and at 535 nm is investigated, respectively, and the results indicate it possesses high quality of optical limiting. 相似文献
20.
We report on a parametric Kerr-lens mode-locked 888 nm pumped Nd:YVO4 1342 nm oscillator using cascaded second-order nonlinearities in LBO. Stable ps-pulse-operation was achieved. For an output
coupling of T=25% high average output power of 6.5 W, emitting Fourier-limited pulses with a duration of 10 ps was reached. By changing
the output coupling to T=10%, we achieved much shorter pulses with a pulse duration of 4 ps for less lower average power of 4.8 W. The beam was diffraction
limited with an M
2 parameter better than <1.05. 相似文献