Typical openaperture zscan results for a film sample with 0. The nonlinear absorption behavior of sr 2 ceo 4 has been investigated using the open aperture zscan technique. Both open and closed aperture zscan techniques were performed at 532 nm and it was found that the dye exhibited a reverse saturable absorption with significant nonlinear absorption. It is based on directly measuring the beam radius in the far field instead of the transmittance of the irradiance through an aperture, as in the original version. And the determination of the two nonlinearities is. Study of thirdorder nonlinear optical properties of undoped. Is the open aperture z scan measurement really necessary in z scan technique. The nonlinear absorption coefficient is calculated using open aperture zscan data, while its. Usually closed aperture zscan data are divided by the open aperture data to cancel the effect of nonlinear absorption contained in the closed aperture measurements. Measurement of the nonlinear refractive index by zscan. It is based on directly measuring the beam radius in the far field instead of the. Modified method for determining nonlinear refractive index. As an experimental case, the nonlinear refractive index of a dye acid blue 9 is calculated using the mentioned method for the first time.
We demonstrate the effectiveness of a simple method for using z scan technique with high repetition rate lasers managing cumulative thermal effects. Thermally managed zscan methods investigation of the size. Closedaperture zscan analysis for nonlinear media with. We use data time correlation to extrapolate with accuracy the instantaneous nonlinear optical response of the sample. Figures, show open and closed aperture zscan curves at 1064 nm at six concentrations of rhodamine b doped pva and 1. The laser beam is directed perpendicular to the plane of the sample. In the present work,thirdorder nonlinear optical properties of undoped and dye doped 1, 7, 7trimethylbicyclo 2. Z scan measurements of the thirdorder optical nonlinearity of a c 60 doped. Nonlinear optical studies of oligomers anisole dyades by.
As the sample travels through the focus of the initial beam, the transmittance either increase or decrease depending on the. Since no nonlinear absorption was observed in a neat polymer film without cdse qds, the observed data was caused by the optical nonlinearity of cdse qds. The zscan characterization of transparent optical materials kit is a simple implementation of the zscan technique that can be used to characterize relatively thin 5mm optical materials. Significant optical nonlinearity is an indicative that brilliant green dye is prominent material for. Under a cw laser beam excitation operated at 532 nm with the power output of 40 mw, a closed aperture setup was used for thermalinduced nonlinear refractive index and an open aperture setup was applied for measuring nonlinearity absorption. Femtosecond and nanosecond nonlinear optical properties of alkyl phthalocyanines studied using zscan technique r. Zscan measurements of the thirdorder optical nonlinearity of a c 60 doped polydimethylacetylendicarboxylate m. Zscan methods yield the real and imaginary parts of nonlinear susceptibility. This method is similar to the above method, however the aperture is removed or enlarged to allow all the light to reach the detector. A typical open aperture z scan data collected at 770nm without chopper, therefore, shows deviation from the expected sheikhbahai model fig. A typical closed aperture zscan output for a thin sample exhibiting nonlinear refraction, is shown in fig. Is the openaperture zscan measurement really necessary in z. In this case, the throughput is sensitive only to the nonlinear absorption. Jan 25, 2014 laser induced nonlinear absorption coefficient of brilliant green solution was measured by single beam open aperture zscan technique using a continuous wave hene laser at the wavelength of 632.
Labview programming language is used for the movement of motion. Hplcgrade alcohols were obtained from sigmaaldrich and were used without further purification. Formatted investigation on the nonlinear optical properties. The z scan characterization of transparent optical materials kit is a simple implementation of the z scan technique that can be used to characterize relatively thin 5mm optical materials. Technology and applications center newport corporation. Physics and astronomy the university of new mexico. Effects of gold nanorods on nonlinear properties of. The openaperture zscan allows measuring the nonlinear absorption coefficient, when the sample is located far from the focal point, the laser radiation intensity is low and tz is close to 1.
We present a theory of open and closed aperture gaussian beam z scan for nonlinear optical materials with saturable absorption and highorder nonlinear refraction. Note, that the zscan response with a fully open aperture is insensitive to the nonlinear refraction and is only a function of the nonlinear absorption 69. The intensity becomes higher as the sample moves closer to the lens focal point. A, 1 1999 662, time evolution of zscan signal is recorded. Nonlinear coefficient determination of aupd bimetallic nanoparticles using zscan. Johnson,1,2,3, siva ram swaminathan,4 dajie zhang,4 and sudhir trivedi4 1department of physics, university of maryland baltimore county, hilltop circle, baltimore, maryland 21250, usa. Femtosecond and picosecond optical nonlinearities of corroles. It was found that the material exhibits multiphoton absorption type optical nonlinearity. The nonlinear refractive index was measured for three different concentration of dma in chloroform by the zscan technique. Picosecond open aperture data clearly suggested the. When the sample approach focus, the measured transmittance in detector either decreases or increases, forming a valley or peak at the focus. The transmittance will be minimum in case of twophoton absorption and maximum for saturable absorption.
The fluorescence lifetime of ir140 have been reported by ganikanov et al 3. Dear colleagues, without nonlinear absorption, the z scan curve corresponding to the pure nonlinear refraction will be. A modification to the wellknown zscan technique for measuring optical nonlinearities is introduced. Nonlinear optical response of noble metal nanoparticles. In order to ascertain the nonlinear optical nlo parameters when the induced phase shift attenuation is small, the closed or open aperture transmittance is analysed using the gaussian decomposition gd technique as a. Experimental techniques and theory abstract zscan and degenerate four wave mixing dfwm are the two specificexperimental. Measurement of nonlinear refractive index in openaperture. Optical nonlinearity of organic dyes as studied by z scan. A typical open aperture zscan data collected at 770nm without chopper, therefore, shows deviation from the expected sheikhbahai model fig. Nonlinear optical response of mgmgo structures prepared by.
In fact, it is not possible to extend further into the absorbing. Observation of twophoton absorption using zscan experiment. The z scan technique has been used extensively to study different materials like semiconductors, nanocrystals, semiconductordoped. Nonlinear characteristic of copper oxide cuo through zscan technique a. Femtosecond and nanosecond nonlinear optical properties of.
The contributions from the twophoton absorption tpa and the nonlinear refraction nlr are easily separated from a closedaperture zscan curve using this method. The zscan transmittance for open aperture saturation absorption and closed aperture nonlinearrefraction are plotted using matlab fig. Determination of nonlinear absorption and refraction by. In the open aperture technique the beam is focused into a detector, after passed through the sample. This is used in order to measure the nonlinear absorption coefficient the main cause of nonlinear absorption is due to twophoton absorption. Investigations of nonlinear optical properties of certain. This in effect sets the normalized transmittance to s 1. When studying the materials nonlinear absorption such as saturable absorption sa and reverse saturable absorption ras, we need to use open aperture zscan technique.
A singlebeam also called zscan method for measuring the sign and magnitude of nonlinear refraction that has simplicity and very high. Study of nonlinear optical properties of nematic liquid. In summary, we can use the matlab program or the numerical methods fitting curve generally to determine n2 and beta from the closed aperture z scan data. Nonlinear optical properties of deoxyribonucleic acid dna. On the other hand without an aperture, the mode of measurement is referred to as open aperture zscan.
In this paper we study the nonlinear optical properties of picogreen dye. Nonlinear coefficient determination of aupd bimetallic. Significant optical nonlinearity is an indicative that brilliant green dye is prominent material. Closed aperture z scan technique using the fresnelkirchhoff. Single beam zscan measurements of nonlinear refraction.
Determination of nonlinear absorption and refraction by single zscan method. 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. Study of nonlinear optical properties of organic dye by z. The difference between normalized peak and valley transmittance. Both open and closure aperture z scan curves were recorded with 40 fs and open z scan curves were recorded with 2 ps laser pulses at same wavelength of 800 nm and nonlinear coefficients were extracted for both studies.
In case of open aperture zscan technique the aperture placed close to the detector is removed and the sample transmission for. For closed aperture z scan both nlr and nla can be measured simultaneously while for another, the nla can be independently measured more accurately. We demonstrate the effectiveness of a simple method for using zscan technique with high repetition rate lasers managing cumulative thermal effects. A sensitive technique for twophoton absorption measurements. Pdf z scan technique through beam radius measurements. Study of thirdorder nonlinear optical properties of. Studies on the nonlinear optical properties of rf plasma polymerized aniline thin films by open aperture z scan technique.
Investigation on thirdorder optical nonlinearities of two. Apr 17, 2010 the close aperture zscan experiment was carried out using fresnelkirchhoff diffraction theory, and the special shape of close zscan curves is determined based on the properties of the diffraction ring pattern. The z scan technique is performed by translating a sample. Dear colleagues, without nonlinear absorption, the zscan curve corresponding to the pure nonlinear refraction will be. Scan measurements of the thirdorder optical nonlinearity.
Closed aperture zscan technique was adopted to characterize. This is used in order to measure the nonlinear absorption coefficient. Narayana rao a, a school of physics, university of hyderabad, hyderabad 500 046, andhra pradesh, india b advanced centre of research on high energy materials acrhem, school of physics, university of hyderabad, hyderabad. Nonlinear optical studies of oligomers anisole dyades by openaperture zscan technique submitted by bouchta sahraoui on tue, 05262015 16. Effects of gold nanorods on nonlinear properties of graphene. Technology and applications center newport corporation application note zscan for the characterization of. The requisite purity of these samples was confirmed through their individual uvvis spectra.
Is the open aperture zscan measurement really necessary in zscan technique. The nonlinear absorption behavior of sr 2 ceo 4 has been investigated using the open aperture z scan technique. We present a theory of open and closed aperture gaussian beam zscan for nonlinear optical materials with saturable absorption and highorder nonlinear refraction. The measurement was carried out using a single beam zscan technique.
Thus, in effect the tpa spectrum without the chopper is reminiscent of the single photon spectra in that wavelength range fig. Laser induced nonlinear absorption coefficient of brilliant green solution was measured by single beam open aperture zscan technique using a continuous wave hene laser at the wavelength of 632. In case of open aperture zscan technique the aperture placed close to the detector is removed and the sample transmission for different z values is measured as before as shown in the fig. Measurement of nonlinear refractive index in openaperture z. Open aperture zscan technique when studying the materials nonlinear absorption such as saturable absorption sa and reverse saturable absorption ras, we need to. What is open aperture and closed aperture in zscan. The experimental setup is shown here below in figure 1 and the schematic of the zscan. For closed aperture zscan both nlr and nla can be measured simultaneously while for another, the nla can be independently measured more accurately. The zscan measurement is a technique which helps to determine intrinsic photophysical properties of photoactivated materials by tightly focusing a single laser beams onto the surface of the material samples. To date the z scan technique is becoming an increas. Here the curve is symmetric with respect to focus z 0.
In this work, the nonlinear optical properties of pure polyaniline and in situ iodine doping polyaniline thin. The nonlinear absorption coefficient is calculated using open aperture z scan data, while its. Zscan technique is one of the simplest and effective. We apply ultrafast single beam zscan technique to measure saturation absorption coefficients and nonlinearrefraction coefficients of primary alcohols at 1560 nm. Experiments are performed using a cw diode laser at 635 nm wavelength and 26 wm. An open aperture zscan study of sr2ceo4 blue phosphor. Third order nonlinear optical properties of oligophenylene dyads by open aperture zscan technique. The calculated effective twophoton absorption coefficient shows that the sr 2 ceo 4 blue phosphor is a promising optical limiting material. Osa zscan measurements using high repetition rate lasers. Experiments are performed using continuous wave cw diode solid state laser at 473 nm wavelength and 20 mw power.
Studies on the nonlinear optical properties of rf plasma polymerized aniline thin films by open aperture zscan technique. Zscan methods yield the real and imaginary parts of nonlinear susceptibility 3 respectively. Is the openaperture zscan measurement really necessary. The nonlinear effects result from vibronic transitions and cubic nonlinearrefraction. Review on theoretical aspect of nonlinear optics 177 on the other hand without an aperture, the mode of measurement is referred to as open aperture zscan. When the sample scanned from negative z position to positive z position, the beam intensity through the sample either increases or decreases. Observation of twophoton absorption using zscan experiment subhajit mishra 4th year, dps, iiserkolkata. Nonlinear optical studies of oligomers anisole dyades by open. The nonlinear optical properties of nematic liquid crystal material have been studied at different concentrations using z scan technique. Open aperture zscan technique when studying the materials nonlinear absorption such as saturable absorption sa and reverse saturable absorption ras, we need to use open aperture zscan technique. The nonlinear refractive index n 2 shows negative nonlinearity for all concentrations studied, and it is measured to be. Open aperture z scan the nonlinear absorption in a nonlinear medium may arise due to multiple photon absorption, saturation of single photon absorption or free carrier absorption. It is a singlebeam technique that gives us both the sign and magnitude of refractive index nonlinearities.
To date the zscan technique is becoming an increas. Modified method for determining nonlinear refractive index of. A brief description on the open and closed aperture zscan is given below. Nonlinear optical properties of polyaniline iodine doped. Effects of gold nanorods on nonlinear properties of graphene films using z scan technique 5 fig. The zscan technique is performed by translating a sample. 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. In case of open aperture z scan technique the aperture placed close to the detector is removed and the sample transmission for. Scan measurements of the thirdorder optical nonlinearity of.
Result of close aperture zscan the closeaperture ca curve was obtained after division of ca data with the oa data to eliminate the contribution of nonlinear absorption and is shown in figure 3. Nonlinear characteristic of copper oxide cuo through z. 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. The nonlinear optical properties of nematic liquid crystal material have been studied at different concentrations using zscan technique. Investigation of optical limiting properties of azophloxine. The investigations involve the singlebeam zscan technique and measurements were carried out at different incident intensities. A, 1 1999 662, time evolution of z scan signal is recorded.
Single beam zscan measurements of nonlinear refraction and. Third order nonlinear optical properties of oligophenylene dyads by open aperture z scan technique. Studies of nonlinear optical properties of picogreen dye. The zscan transmittance for open aperture saturation absorption and closed aperture. Pdf studies on the nonlinear optical properties of rf. Three different wavelengths 457, 488 and 514 nm were used for. We have briefed about both open and closed aperture experiment. Corrole ttc b triphenyl corrole tpc studied using the z scan technique. Thermally managed zscan methods investigation of the sizedependent nonlinearity of graphene oxide in various solvents paul burkins,1,3 robinson kuis,3 isaac basaldua,2,3 anthony m.