To investigate the saturable absorption properties of the fewlayer tmds in the visible wavelength, the openaperture oa z scan technique see methods was carried out at 635 nm, our redlight fibre laser operation wavelength. The wavelength dependence of the nonlinear absorption of a bisphthalocyanine, ndpc2, dissolved in dimethyl formamide was studied in the rising part of the qband using the open aperture zscan technique, to determine the wavelength region over which the nonlinear absorption changes from reverse saturable absorption to saturable absorption. Electron microscopy verified the high quality of the twodimensional mos2 nanostructures. Open aperture zscan at different energies for au seed is shown in figure 5. Nonlinear saturable absorption of the sodium borosilicate. Coherent control of optical limiting in atomic systems. It is shown that the sensitivity of the zscan measurements on a saturable absorber using radially polarized beams has the great improvement compared with those using the scalar light beams such as gaussian beams, laguerregaussian beams, and tophat beams. It is found that groundstate plasma bleaching thirdorder nonlinearity and threephoton absorption horder nonlinearity play a vital role in the transition of optical nonlinearity from sa to rsa under strong photoexcitation. Zscan technique is applied to a saturable medium described by a generalized threelevel scheme of photoexcitation in the condition of overlapping spectra of the ground and excited states. Thirdorder nonlinear optical properties and reverse saturable absorption in 2,3butanedione dihydrazone using z scan technique v. Zscan results reveal that the composite films exhibit selfdefocusing nonlinearity. Two important situations are encountered here, namely, saturable and reverse saturable absorption sa and rsa. The optical nonlinear absorption nla property of multilayer graphene was investigated by zscan technique with picosecond laser pulse of 532nm wavelength.
Application of zscan technique for the study of nonlinear absorption. Nonlinear optical properties of laser synthesized pt. Osa zscan technique for quantifying the excitedstate. Saturable and reverse saturable absorption in silver nanodots. Lal d adepartment of applied physics, guru jambheshwar university of science and etchnology hisar125001, haryana, india. The enhanced saturable absorption of mos2graphene nanocomposite films compared with pristine mos2 film and graphene film is investigated using an openaperture z scan technique with a femtosecond laser at 800 nm. Saturable absorption sa and reverse saturable absorption rsa at 532 nm were observed in ag nanodots prepared by pulsed laser deposition. This technique is applied to study photorefractive properties of polymer films containing. The real 3re and imaginary im 3 parts of the third order nonlinearity of these. However, the fundamental origin and thickness dependence.
Zscan technique is applied to a saturable medium described by a generalized threelevel scheme of photoexcitation. Pdf application of the zscan technique to a saturable medium. Pdf application of the zscan technique to a saturable. In this article, the zscan method has been corrected for the case of saturation in absorption. Recently, 2d ti 3 cnt x t x represents functional groups such as oh and f was found to exhibit nonlinear saturable absorption sa or increased transmittance at higher light fluences, which is useful for mode locking in fiber. Our nonlinear absorption study shows that there is.
Using the principle relations of the changes in the transmitted beam through a kerr sample and fresnelkirchoff integral method, a proper model is. Theoretical and experimental study of the excited state dynamics in reverse saturable absorbers using z scan technique s. It should be noticed that twophoton absorption tpa threshold is found to be higher than the stability range of excitation power, that is why we concern ourselves only with saturable absorption in this experiment. The nonlinear absorption nla properties of copper phthalocyanine cupc solution in acetone were investigated by the femtosecond openaperture oa zscan technique. Nonlinear optics properties of multifunctional fullerenol. The transmittance will be minimum in case of twophoton absorption and maximum for saturable absorption.
Comsol is well suited for modeling the dynamics of reverse saturable absorption. It should be noticed that twophoton absorption tpa threshold is found to be higher than the stability range of excitation power, that is why we concern ourselves only. Closed aperture zscan non linear refractive index can be measured using closed aperture zscan. An improved zscan analysis approach is proposed by establishing and solving the saturable absorption sa and reversesa rsa models, respectively. Both open and closed aperture zscan techniques were performed and it was found that the dye showed reverse saturable absorption and intensitydependent positive nonlinear refraction. The zscan method has gained rapid acceptance by the nonlinear optics community as a. Threephoton absorption of copper phthalocyanine solution by.
We present a theory of open and closedaperture gaussian beam zscan for nonlinear optical materials with saturable absorption and highorder nonlinear refraction. Enhanced nonlinear saturable absorption of mos2graphene. Investigation of optical limiting properties of azophloxine. Thirdorder nonlinear optical properties and reverse saturable absorption in 2,3butanedione dihydrazone using zscan technique v. Pdf the zscan technique is adapted for measuring the nonlinear part of refractive index in a medium with the excited state saturable absorption. Molybdenum disulfide mos2 as a broadband saturable absorber. Saturable absorption and reverse saturable absorption play an important role in the studies of the nonlinear optical properties of nanoparticles at resonant excitation.
It is shown that the sensitivity of the zscan measurements on a saturable absorber using radially polarized beams has the great improvement compared with those using the scalar light beams such as gaussian beams, laguerregaussian beams. Zscan analytical theory for material with saturable absorption and. We show that an approximate expression for a transmitted intensity through the nonlinear optical material is possible by means of the adomians decomposition method and the thin film approximation. The wavelength dependence of the nonlinear absorption of a bisphthalocyanine, ndpc2, dissolved in dimethyl formamide was studied in the rising part of the qband using the open aperture z scan technique, to determine the wavelength region over which the nonlinear absorption changes from reverse saturable absorption to saturable absorption. A shift from saturable absorption to reverse saturable absorption was observed at higher input pump intensities. Thirdorder nonlinear optical properties and reverse. Effect of size on the saturable absorption and reverse. In order to perform reliable measurements, it is necessary to. Power dependent of nonlinear absorption coefficient of cdse. An improved z scan analysis approach is proposed by establishing and solving the saturable absorption sa and reversesa rsa models, respectively. Correctness of the zscan data interpretation is analyzed in.
Osa modeling and identification on nonlinear saturable and. Technology and applications center newport corporation. We present a theory of open and closedaperture gaussian beam z scan for nonlinear optical materials with saturable absorption and highorder nonlinear refraction. Closedaperture zscan analysis for nonlinear media with. Zscan experiment zscan measurement is a technique used for measuring nonlinear refractive index and nonlinear absorption coe cient. Chromiumdoped saturable absorbers investigated by the z. Mxenes comprise a new class of 2d transition metal carbides, nitrides, and carbonitrides that exhibit unique lightmatter interactions. And the physical mechanism of rsa effect was revealed, which was originated from threephoton absorption. Zscan technique for quantifying the excitedstate parameters of the reverse saturable absorbing dye 1,1. Open aperture z scans showed a competition between saturable absorption sa and reverse saturable absorption. The zscan technique is performed by translating a sample through the beam waist of a focused beam and then measuring the power transmitted through the sample. Zscan technique for saturable absorption using diffraction. Saturable absorption in 2d ti3c2 mxene thin films for passive.
The z scan technique is used as a standard method to study the nonlinear optical response,39 where the incident laser power is fixed and the irradiance on the sample is changed by scanning the sample position around the laser focal point. In a typical open aperture zscan experiment, total transmission of light through the sample is recorded as the sample is translated about the focal point a focused laser beam. Ultrafast saturable absorption of twodimensional mos2. Thirdorder optical nonlinearity and optical power limiting of organic materials under cw laser illumination. Z scan technique is applied to a saturable medium described by a generalized threelevel scheme of photoexcitation in the condition of overlapping spectra of the ground and excited states. The saturable absorption response of the pt nps was switched to the reverse saturable absorption in the higher laser intensities. In the standard z scan technique, a large sample size and good sample homogeneity are required. Recently, 2d ti 3 cnt x t x represents functional groups such as. In this case called reverse saturable absorption rsa 11, the sample. The measurements were carried out at different input peak intensities of nanosecond nd. Z scan curves are readily reproducible without change in linear transmittance of the samples 11. Zscan technique for nonlinear materials characterization. In this chapter, recent results on the nonlinear optical properties of mnps including gold, silver, palladium, and platinum have been discussed.
Characteristics of saturable absorption of mos films in the. The nonlinear refractive index that has a negative value was increased from. Nearinfrared femtosecond zscans are carried out on the synthesized gold nanorods nrs possessing the average length of 46 nm using a femtosecond laser operated at the wavelength of 800 nm, which is close to the peak position of longitudinal. Pdf zscan technique for saturable absorption using. The special nonlinear optical response of noble metal nanoparticles mnps when exposed to intense laser radiation has induced novel applications in nonlinear spectroscopy, optoelectronics, and optical switchers and limiters.
The thirdorder nonlinear optical absorption of the glass is investigated in detail using the openaperture zscan technique at the wavelength of 770 nm with a pulse width of 200 fs. Determination of third order optical nonlinearity in a. Correctness of the zscan data interpretation is analyzed in framework of the model. The optical nonlinear absorption of the aqueous solution of platinum nanospheres protected by poly nvinyl2pyrrolidone was investigated using open aperture zscan method with nanosecond pulse laser at the wavelength of 532 run. Both open and closed aperture z scan techniques were performed and it was found that the dye showed reverse saturable absorption and intensitydependent positive nonlinear refraction. We develop the zscan technique on a saturable absorber under the excitation of radially polarized beams.
Using the z scan technique with 532 nm laser pulses of dual widths in the picosecond regime, we distinguish between twophoton absorption tpa and excited state absorption esa. Using the principle relations of the changes in the transmitted beam through a kerr sample and fresnelkirchoff integral method, a proper model is offered to evaluate the electric field in any point of the far field. Principle z scan technique is based on the principle of spatial beam distortion. Studies on thirdorder nonlinear optical properties and. Investigation of saturable and reverse saturable absorptions for graphene by zscan technique abstract. Chromiumdoped saturable absorbers investigated by the zscan. It is observed that the typical three main raman peaks.
The zscan technique is used as a standard method to study the nonlinear optical response,39 where the incident laser power is fixed and the irradiance on the sample is changed by scanning the sample position around the laser focal point. Theoretical and experimental study of the excited state. Observation of twophoton absorption using zscan experiment. In a typical open aperture z scan experiment, total transmission of light through the sample is recorded as the sample is translated about the focal point a focused laser beam. F was found to exhibit nonlinear saturable absorption sa or increased transmittance at higher light fluences, which is useful for mode locking in fiber. The real and imaginary parts of the thirdorder nonlinear optical susceptibility were of the order 10. The reverse saturable absorption rsa phenomenon was observed. It is shown that the sensitivity of the z scan measurements on a saturable absorber using radially polarized beams has the great improvement compared with those using the scalar light beams such as gaussian beams, laguerregaussian beams, and tophat beams. The zscan technique is adapted for measuring the nonlinear part of refractive index in a medium with the excited state saturable absorption. Zscan technique for saturable absorption using diffraction method in. The effective excitedstate absorption cross section was found to be larger than the ground state absorption cross section, indicating that the.
Thickness dependence of a giant nonlinear saturable absorption. Related content thirdorder nonlinear optical properties of two novel fullerene derivatives yongguang cheng, haoshan hao, haixia xiao et al. We observed reverse saturable absorption rsa at 435 nm in both of the solvents, and a transition from saturable absorption sa to rsa with an increase in either. Correctness of the z scan data interpretation is analyzed in. Nearinfrared femtosecond z scans are carried out on the synthesized gold nanorods nrs possessing the average length of 46 nm using a femtosecond laser operated at the wavelength of 800 nm, which is close to the peak position of longitudinal. Enhanced sensitivity of the zscan technique on saturable. It is shown that the sensitivity of the z scan measurements on a saturable absorber using radially polarized beams has the great improvement compared with those using the scalar light beams such as gaussian beams, laguerregaussian beams. Nonlinear optical studies of c4h94nnidmit2 by zscan. Thirdorder nonlinear optical properties and reverse saturable. Rp photonics encyclopedia zscan measurements, kerr. Theoretical and experimental study of the excited state dynamics in reverse saturable absorbers using zscan technique s.
The enhanced saturable absorption of mos2graphene nanocomposite films compared with pristine mos2 film and graphene film is investigated using an openaperture zscan technique with a femtosecond laser at 800 nm. Nanocrystals, zscan technique, three photon absorption. This technique is applied to study photorefractive. Nonlinear optical response of noble metal nanoparticles.
To investigate the saturable absorption properties of the fewlayer tmds in the visible wavelength, the openaperture oa zscan technique see methods was carried out at 635 nm, our redlight fibre laser operation wavelength. Through an open aperture zscan technique with femtosecond pulses at. In this section i have brie y described the zscan experiment. To account for reverse saturable absorption in chloroaluminum phthalocyanine dissolved in methanol both tpa and esa, rather than either one, need be invoked. The nonlinear absorption nla properties of copper phthalocyanine cupc solution in acetone were investigated by the femtosecond openaperture oa z scan technique. Zscan curves are readily reproducible without change in linear transmittance of the samples 11. Bulk saturable absorption in topological insulator thin films. Saturable and reverse saturable absorption of rhodamine b in. Paradoxical combination of saturable absorption and reverse.
Chapter 2 40 absorption nonlinearity and reverse saturable absorption is known as positive type of absorption nonlinearity. A diode laser at 780 nm passes through the electrooptic modulator eom. On the other hand, when the sb concentration increased in. Nonlinear saturable absorption of all the asprepared fewlayer tdms ws 2, mos 2, mose 2 could be observed in our. Request pdf zscan analytical theory for material with saturable absorption and twophoton absorption by using the adomian decomposition method, we. The thirdorder nonlinear optical absorption of the glass is investigated in detail using the openaperture z scan technique at the wavelength of 770 nm with a pulse width of 200 fs. In this article, the z scan method has been corrected for the case of saturation in absorption. Wavelength dependence of nonlinear absorption in a bis. Quantification of nonlinear absorption in ternary assbse. Ultrabroadband nonlinear saturable absorption for two. Jan 15, 2018 mxenes comprise a new class of 2d transition metal carbides, nitrides, and carbonitrides that exhibit unique lightmatter interactions. In recent years, zscan technique with femtosecond fs pulse is a rapid and sensitive method to characterize carrier transition in the correlated materials through recording nlo response. Nonlinear characteristic of copper oxide cuo through z.
Using a parameter sweep in comsol using the zposition of the sample as the parameter, the zscan experiment was simulated. The results show that the transformation from saturable absorption to reverse saturable absorption in the glass is observed with the increase of the input light. As nonlinear absorption can affect the measurement of the nonlinear index, the open method is typically used in conjunction with the closed method. Saturable absorption in 2,3butanedione dihydrazone. Zscan measurements of organic nonlinearities physics and. Principle zscan technique is based on the principle of spatial beam distortion. In nonlinear optics zscan technique is used to measure the nonlinear index n 2 kerr nonlinearity and the nonlinear absorption coefficient via the closed and open methods, respectively. In the standard zscan technique, a large sample size and good sample homogeneity are required. Abstractthe zscan technique is adapted for measuring the nonlinear part of refractive index in a medium with the excited state saturable absorption. In addition, openaperture and closeaperture zscan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the grown mos2. Determining nonlinear optical properties using the zscan technique. We develop the z scan technique on a saturable absorber under the excitation of radially polarized beams. Employing highyield production of layered materials by liquidphase exfoliation, molybdenum disulfide mos2 dispersions with large populations of single and few layers were prepared. Nonlinear characteristic of copper oxide cuo through zscan.