Closed-aperture Z-scan Research Articles

Method for an accurate measurement of nonlinear refractive index in the case of high-repetition-rate femtosecond laser pulses

In this report, we propose a new method for measuring the nonlinear refractive index in liquid and glass samples using femtosecond (fs)-laser pulses with high pulse repetition rates. This method is based on solving the heat equation to derive an expression for the normalized transmittance of closed-aperture Z-scan measurements as a function of the accumulative thermal lens induced by a high-repetition-rate fs laser pulse. To validate this method, the nonlinear refractive indices of acetone as a liquid and soda-lime as a glass material have been measured using a 100 fs pulse duration, 80 MHz repetition rate, and 800 nm wavelength. The extracted nonlinear refractive index is in a good agreement with the reported one using 1 kHz repetition rate fs laser pulses.

High Repetition-Rate Laser Z-Scan Measurements: Criterion for Recognizing Adverse Thermal Effects

This study reports z-scan measurements in which high-repetition-rate and reduced repetition-rate (pulse-picked) laser beams were employed using a standard sample, carbon disulfide (CS2) contained in supposedly high damage-threshold spectroscopic-grade pristine fused-quartz cuvettes. The results suggest that at reduced repetition rates, the closed aperture z-scan profile for CS2 displays the expected configuration. However, at high repetition-rates the closed aperture z-scans are distinctly different resulting in unexpectedly large nonlinear refractive index of CS2 due to thermal effects that resulted in below-threshold laser-induced damage of the cuvettes. Normaski microscope images confirm the damage and open aperture z-scan study of the damaged fused-quartz cuvettes yielded about two orders of magnitude enhancement in the nonlinear absorption coefficient of silica. Based on these findings, the necessary criterion for recognizing below-threshold laser-induced damage in any high-repetition-rate laser z-scan measurement has been formulated in order to help avoid erroneous interpretation of the origin and strength of nonlinear response in such studies.

Effect of gold plasmonic shell on nonlinear optical characteristics and structure of iron based nanoparticles

Growth of the gold plasmonic shells on the iron based nanoparticles could enhance the linear and nonlinear optical properties of the iron based nanostructures, due to the coupling of the localized surface plasmon (LSP) modes on the inner and outer surface of each Au-shell. We have fabricated the iron based nanoparticles via arc discharge technique in water that is a cost effective and simple single-step synthesis route. Then, the gold shells have been grown chemically on the iron-based cores. The structural properties of core-shell nanoparticles have been investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD measurements have exposed the existence of three phases of iron (oxides) including pure iron, magnetite, and wustite within the cores. TEM images have shown that the average core-shell size with the size distribution in the range of 10 to 80 is 25 ± 10 nm. The UV–visible optical and closed-aperture Z-scan measurements have verified the coupling LSP modes coupling between the inner and outer surfaces of the Au-shells covering the iron based cores. The experimentally obtained UV–visible spectra have qualitatively verified the numerical results obtained using the finite element simulation method.

Structural and Femtosecond Third-Order Nonlinear Optical Properties of Sodium Borate Oxide Glasses: Effect of Antimony

Structural and optical properties of antimony-containing sodium borate glasses were studied and their ultrafast third-order nonlinear optical (NLO) properties have been evaluated using Z-scan measurements with femtosecond (fs) pulses (∼150 fs, 80 MHz) at 750, 800, and 880 nm wavelengths. Glasses in the (mol %) 20Na2O–(80 – x)B2O3–xSb2O3 (where x = 0, 10, 20, and 30) system have been fabricated via melt quench technique. The structural modifications were analyzed using the Raman and magic angle spinning (MAS)-nuclear magnetic resonance (NMR) (11B MAS-NMR and 23Na MAS-NMR) techniques. The optical absorption spectra revealed that the absorption edge was red-shifted, suggesting the decrease in band gap energy with increase of antimony content in the glasses. Raman scattering results revealed that the boroxol rings are depressed with the incorporation of Sb2O3 for replacing B2O3. 11B MAS-NMR results showed a progressive increase of B4 units at the expense of B3 units. The Raman and 11B MAS-NMR results support the formation of Sb5+ ions due to oxidation of Sb3+ that played the role of charge compensation. 23Na MAS-NMR spectra revealed a decreasing trend in the average of bond lengths of Na–O with increasing Sb2O3 contents. This suggested that sodium changed its role from charge compensator to modifier cation. The antimony-containing glasses demonstrated a reverse saturable absorption in open-aperture Z-scan mode due to two-photon absorption, while closed-aperture Z-scan signatures depicted positive nonlinear refraction due to self-focusing effect. The NLO coefficients were found to increase with Sb2O3 due to the increased nonbridging oxygens and also due to the hyperpolarizability of Sb3+ and Sb5+ ions. The observed NLO data clearly suggest that the investigated glasses are beneficial for optical limiting applications.

Illustrious influence of amino acid L-threonine (LT) on structural and optical insights of Zinc Thiourea Sulphate (ZTS) crystal

Mentioned communication explores the modification in properties of Zinc Thiourea Sulphate (ZTS) crystal due to L-Threonine (LT) addition. Superior quality LT-doped ZTS crystal with 0.5 M% concentration of LT was grown by the slow evaporation solution growth technique. Powder X-ray diffraction technique was applied to study the cell parameters which confirmed orthorhombic crystal structure of both pure and LT-ZTS crystal with slight variation in cell parameters. Shimatzu make spectrophotometer confirmed the UV-Visible spectral analysis in the range of 200–900 nm which affirmed the 94% transmittance, enhanced bandgap value (4.72 eV), lower cut-off value (246 nm) and lower optical constants viz. extinction coefficient, polarizability, refractive index, and reflectance of LT-ZTS crystal. The higher second harmonic generation (SHG) efficiency of LT-doped ZTS was pointed by Kurtz Perry powder method (3.06 times of pure ZTS crystal and 3.62 times of KDP crystal) using Nd: YAG laser. The colour centered emission and electronic purity of parent and doped ZTS crystals were examined which resulted in the violet emission in visible region for both pure and LT-ZTS crystals. Z-scan technique is used to identify the Kerr lensing nonlinearity in pure and LT-doped ZTS crystal. Close aperture Z-scan curve demonstrated negative refraction nonlinearity (self-defocusing nature) for pure and positive refraction nonlinearity (self-focusing nature) for LT-ZTS crystal. Calculated value of refraction nonlinearity n2 is −2.2 × 10[Formula: see text] cm2/W for pure ZTS and [Formula: see text]4.99 × 10[Formula: see text] cm2/W for LT-ZTS crystal. Open aperture Z-scan showed reverse saturable absorption effect (RSA) in pure ZTS and saturable absorption effect (SA) in LT-ZTS crystal. The [Formula: see text] value is 2.85 × 10[Formula: see text] cm/W for pure ZTS and 3.92 × 10[Formula: see text] cm/W for LT-ZTS crystal. The [Formula: see text]3 of ZTS crystal is 6.133 × 10[Formula: see text] cm/W and 1.655 × 10[Formula: see text] cm2/W for LT-ZTS crystal. The transition in TONLO parameters is observed due to doping of LT in ZTS. The obtained parameters indicated the superiority of LT-ZTS for application in distinct laser stabilization systems, UV shelter and NLO applications.

Tuning optical properties of cadmium thiourea acetate nonlinear optical crystal exploiting organic ligand of L-proline

Modifying optical properties of crystal is very fundamental need for designing various photonic devices, hence in the current investigation, the L-proline (LP) has been firstly doped in cadmium thiourea acetate (CTA) crystal with the aim to optimize the UV–Visible, second harmonic generation (SHG) efficiency, luminescence and third-order nonlinear optical (TONLO) properties of CTA crystal. The pure and doped CTA crystals have been grown by slow solvent evaporation technique at [Formula: see text]C. The structural parameters of grown crystals have been determined using the single crystal X-ray diffraction technique. The incorporation of LP in CTA crystal matrix has been confirmed by Fourier transforms infrared analysis. The UV–Visible studies have been employed within the wavelength range of 200–900 nm to explore the enhancing impact of LP on CTA crystal. The LP doped CTA crystals were subjected to Kurtz–Perry test and Z-scan analysis to identify the nonlinear nature of studied crystals. The SHG efficiency of LP-CTA crystal shows significant increase owing to enhanced charge transfer over the organic ligand of LP. The laser-induced TONLO properties of LP-doped CTA crystal have been determined at 632.8 nm. The nature of nonlinear refraction and absorption has been explored by close and open aperture Z-scan configuration. The magnitude of nonlinear refraction [Formula: see text], absorption coefficient [Formula: see text], cubic susceptibility [Formula: see text] and figure of merit has been determined using the transmittance data. The color-centered luminescence studies have been carried out which established the prominent redshift in peak maxima of emission wavelength of CTA crystal due to doping of LP. Comparative analysis of pure and doped crystal confirmed the dominance of LP doping.

Growth and Spectroscopic Studies on the L-Tartaric Acid Doped Ammonium Dihydrogen Phosphate Non-Linear Optical Single Crystals

Single crystals of L-Tartaric acid doped Ammonium Dihydrogen Phosphate (LTADP) were grown by slow solvent evaporation technique at ambient conditions. Single Crystal X-ray diffraction (SXRD) analysis was carried out to know the lattice parameters and structure of the grown crystal. Fourier transform infrared spectral analysis was carried out to examine the presence of various functional groups in the LTADP single crystals. Thermo gravimetric (TG) and Differential thermal analyses (DTA) were used to study the thermal properties of the grown crystal. Second harmonic generation (SHG) efficiency measurement was done to examine the enhancement in the nonlinear optical characteristics of the grown crystals. Intensity can be observed from the photoluminescence study. The close and open aperture Z-scan configuration has been used to evaluate the nature of third order nonlinear optical refraction (n2) and absorption (β) for the grown LTADP single crystal

Identification and separation of local and nonlocal optical nonlinear refraction effects: theory and experiment

Understanding the nonlinear optical effect of novel materials plays a crucial role in the fields of photonics and optoelectronics. Herein, we theoretically and experimentally investigate the simultaneous presence of third-order locally refractive nonlinearity and thermally induced nonlocal nonlinearity saturation. We present analytical expressions for the closed-aperture Z-scan trace and the number of spatial self-phase modulation (SSPM) rings, which allows one to unambiguously and conveniently separate the contributions of local and nonlocal nonlinear refraction in the case that both effects occur simultaneously. As a test, we study both the local and thermally induced nonlocal nonlinear refraction in fullerene/toluene solution by performing continuous-wave Z-scan and SSPM measurements at two different wavelengths. This work enriches the understanding of the physical mechanism of the optical nonlinear refraction effect in solution dispersions of nanomaterials, which can be exploited for nonlinear photonic devices.

Large nonlinear refraction in pulsed laser deposited BCZT thin films on quartz substrates

Optical thin films based on ferroelectric materials are forerunners for novel optoelectronic and photonic applications due to their large inherent coupling between optical and electrical properties. We report here on the thickness dependence of linear and nonlinear optical properties of polycrystalline Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) thin films fabricated on quartz substrates by the pulsed laser deposition technique. In order to probe the linear optical properties of BCZT thin films, we have obtained optical transmission spectra from which the optical parameters like the refractive index and extinction coefficient were deduced using the Swanepoel method. Using the Sellemier relation, we have estimated the oscillator parameters like oscillator strength and oscillator energy from the refractive index dispersion data, which are indicative of the efficiency of the electro-optic coupling process. Further, the third-order optical nonlinearity of these thin films was measured by a closed-aperture Z-scan technique with a low-power, continuous-wave He–Ne laser as the excitation source. These films exhibited high optical nonlinearity, and the nonlinear refractive index was determined to be ∼5×10−7 m2/W. The enhanced nonlinear refraction in BCZT thin films at the low power regime could be attributed to both photothermal and photorefractive origin with a plausible larger contribution from the latter. Such a large nonlinear optical response exhibited at low optical powers in BCZT thin films is very promising technologically, as it may find applications in a number of photonic devices such as optical interconnects, optical processors, optical memories, and waveguide modulators.

Comparative analysis on microhardness and third order nonlinear optical traits of pure and Nd3+ doped zinc tris-thiourea sulphate (ZTS) crystal

Abstract Present investigation is aimed to explore the single crystal growth, microhardness and third order nonlinear optical (TONLO) properties of Nd3+ doped zinc tris-thiourea sulphate (ZTS) crystal. The commercial slow solvent evaporation technique has been chosen to grow a good quality ZTS (12 mm × 0.5 mm × 0.3 mm) and Nd3+ doped ZTS (11 mm × 0.6 mm × 0.4 mm) single crystals. Vickers microhardness test has been employed to analyze the influence of Nd3+ dopant on the hardness behavior of ZTS single crystal. The TONLO effects occurring in Nd3+ doped ZTS single crystal have been evaluated by means of Z-scan technique using a He–Ne laser operating at 632.8 nm. The close and open aperture Z-scan configuration have been used to determine the nature of TONLO refraction n2 and absorption β, respectively. The magnitudes of vital TONLO parameters, such as refraction n2, absorption coefficient β, figure of merit and susceptibility χ3 of the Nd3+ doped ZTS single crystal, have been determined using Z-scan transmittance data. The n2, β, and χ3 of Nd3+ doped ZTS single crystal were found to be of the order of 10−10 cm2/W, 10−6cm/W and 10−5 esu, respectively.

Role of precursors' ratio for growth of two-dimensional MoS2 structure and investigation on its nonlinear optical properties

In this study, thin films containing mono and few-layer MoS2 were directly synthesized by one-step thermal chemical vapor deposition on Si/SiO2 substrate. The effects of precursors' ratios including sulfur and MoO3 powders were systematically studied by altering sulfur content for the growth of MoS2 nanoflakes. The X-Ray diffraction patterns and scanning electron microscopy confirmed the formation of MoS2 nanoflakes in sulfur contents of 500 and 1000 mg. According to the line width and frequency difference between the E12g and A1g in Raman spectroscopy, the nanoflakes grown with sulfur content of 500 and 1000 mg were two-dimensional MoS2 structures having few numbers of layers. Moreover, it was verified by assessment of the nanoflakes' band gap via UV–visible and photoluminescence analysis. In addition, the open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the synthesized nanoflake in sulfur content of 500 mg. The experiments were performed using a diode laser with a wavelength of 532 nm as light source at different powers. The nanoflakes displayed considerable saturable absorption (SA) under low laser power and reverse saturable absorption (RSA) at higher laser powers. In general, few-layered MoS2 would be useful for the development of nanophotonic devices like optical limiters, optical switchers, etc.

Evaluation of nonlinear optical differences between breast cancer cell lines SK-BR-3 and MCF-7; an in vitro study.

This study aimed to explore the potential of the Z-scan technique to improve accuracy in identifying SK-BR-3 and MCF-7 breast cancer cell lines. Three in vitro samples were prepared for each breast cancer cell line. A closed-aperture Z-scan technique was used to measure the sign and magnitude of the nonlinear refractive index of each sample. Prior to the Z-scan, all samples were fixed with 1 mL of 5% paraformaldehyde. The sign of the nonlinear refractive indices of MCF-7 and SK-BR-3 breast cancer cell lines were negative and positive, respectively. The repeated Z-scan measurements for all samples of each cell line were similar. The results indicated that the proposed bio-optical method is a reliable method for characterizing differences in various breast cancer cell types. It is suggested that the nonlinear refractive index of cells be considered as an indicator for differentiating various breast cell lines from each other.

Nonlinear optical responses of carbon quantum dots anchored on graphene oxide hybrid in solid-state transparent monolithic silica gel glasses

Exploring the nonlinear optical (NLO) response of graphene-based hybrids in solid-state three-dimensional macrostructures is vital to promote the practical development of graphene-based photonic and optoelectronic devices. Here, a solid-state hybrid of ultrafine and well-dispersed carbon quantum dots (CQDs) supported on graphene oxide (GO) was chosen as representative of such materials. The hybrid was introduced into organically modified silica gel glasses using a facile sol-gel wet chemical technique to obtain stable transparent monolithic nanocomposites, and their practical application in nonlinear optics was explored. The NLO performances were investigated by the open-aperture (OA) and closed-aperture (CA) Z-scan techniques in the nanosecond regime using a laser with a wavelength of 532 nm. The as-prepared CQD/GO SiO2 gel glasses displayed completely different NLO behavior from that of a CQD/GO suspension. The NLO performance of CQD/GO significantly improved after incorporation into SiO2 gel glasses because of the more graphitized structure of the CQD/GO hybrid. Both the OA and CA Z-scan patterns suggested that the NLO properties of the CQD/GO suspension combined nonlinear absorption and nonlinear scattering, while the NLO response of the CQD/GO SiO2 gel glasses stemmed primarily from nonlinear absorption and nonlinear refraction. In addition, this is the first report of the third-order nonlinear susceptibility χ(3) of a CQD/GO hybrid doped in solid-state gel glasses. The present results therefore demonstrate the feasibility and versatility of CQD/GO silica gel glasses, a promising new class of highly efficient NLO materials that can be applied in optical communications, radiofrequency optoelectronics, and all-optical signal processing.

Nonlinear optical properties of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 investigated by the femtosecond Z-scan technique

Nonlinear optical properties in La-modified ( 1-x ) Pb ( Mg1/3Nb2/3 ) O3-xPbTiO3 (PMN-PT) (3/75/25) transparent ceramic are studied. The optical nonlinearity is investigated employing Z-scan technique at the off-resonant wavelengths of 515 and 1030 nm. The two-photon absorption coefficient is measured up to be 9.6 cm / GW at 515 nm, and three-photon absorption coefficient is found to be 0.091 cm3 / GW2 at 1030 nm. When an external electric field was applied to the PMN-PT, we found that the electric field increased from 0 to 3 kV / cm in the closed-aperture Z-scan experiment with the wavelength of 515 nm, whereas the nonlinear refractive index n2 increased from 1.85 × 10 − 8 esu to 3.87 × 10 − 8 esu, an increase of 110%. The large nonlinear effect could be applied in areas such as sensor protection and telecommunications and to write permanent refractive index structures into the interior of optical materials, which may make a difference in integrate optoelectronic devices progress.

Investigation on nonlinear optical properties of MoS2 nanoflakes grown on silicon and quartz substrates

In this study, MoS2 nanoflakes were directly grown on different substrates—Si/SiO2 and quartz—by one-step thermal chemical vapor deposition using MoO3 and sulfide powders as precursors. Scanning electron microscopy and x-ray diffraction patterns demonstrated the formation of MoS2 structures on both substrates. Moreover, UV-visible and photoluminescence analysis confirmed the formation of MoS2 few-layer structures. According to Raman spectroscopy, by assessment of the line width and frequency shift differences between the and A1g, it was inferred that the MoS2 grown on the silicon substrate was monolayer and that grown on the quartz substrate was multilayer. In addition, open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the grown MoS2. All experiments were performed using a diode laser with a wavelength of 532 nm as the light source. It is noticeable that both samples demonstrate obvious self-defocusing behavior. The monolayer MoS2 grown on the silicon substrate displayed considerable two-photon absorption while, the multilayer MoS2 synthesized on the quartz exhibited saturable absorption. In general, few-layered MoS2 would be useful for the development of nanophotonic devices like optical limiters, optical switchers, etc.

Investigation on nonlinear optical properties of MoS2 nanoflake, grown on silicon and quartz substrates

In this study, MoS2 was directly synthesized by one-step thermal chemical vapour deposition (TCVD), on different substrates including Si/SiO2 and quartz, using MoO3 and sulfide powders as precursor. The XRD patterns demonstrate the high crystallinity of MoS2 on Si/SiO2 and quartz substrates. SEM confirmed the formation of MoS2 grown on both substrates. According to line width and frequency difference between the E12g and A1g in Raman spectroscopy, it is inferred that the MoS2 grown on Si/SiO2 substrate is monolayer and the MoS2 grown on quartz substrate is multilayer. Moreover, by assessment of MoS2 nanoflake band gap via UV-visible analysis, it verified the formation of few layer structures. In addition, the open-aperture and close-aperture Z-scan techniques were employed to study the nonlinear optical properties including nonlinear absorption and nonlinear refraction of the synthesized MoS2. All experiments were performed using a diode laser with a wavelength of 532 nm as light source. The monolayer MoS2 synthesized on Si/SiO2, display considerable two-photon absorption. However, the multilayer MoS2 synthesized on quartz displayed saturable absorption (SA). It is noticeable that both samples demonstrate obvious self-defocusing behaviour.

Role of defect states on nonlinear properties of 8 MeV electrons irradiated zinc oxide thin films under off-resonant regime

In the present work, ZnO thin films were synthesized by sol-gel with subsequent spin coating on corning glass substrates. To understand the variations in the structural, optical, and nonlinear optical properties of ZnO thin films, 8 MeV electron irradiation with different dose rates (0 kGy, 1 kGy, 5 kGy, and 10 kGy) was performed. The XRD spectra showed transition from polar crystal growth orientation to non-polar crystal growth orientation of the films when the irradiation dose rate was increased from 0 kGy to 10 kGy and this was attributed to the reduced thickness of the irradiated films. The generation of localized surface states below the conduction band upon electron irradiation was confirmed by the quantification of the Urbach energy. A large band gap shrinkage was observed in the irradiated films (3.31–3.10 eV) due to the enhanced surface states. The photoluminescence spectra showed reduction in the NBE emission due to the enhanced surface states in the irradiated films. Open aperture and closed aperture Z-scan measurements were performed to extract the nonlinear absorption coefficient (β) and nonlinear refractive index (n2) values using 532 nm Nd:YAG laser having pulse width of 7 ns. The open aperture Z-scan profiles of the films showed the presence of normalized transmittance valley, which was attributed to the two photon absorption (TPA) behaviour. The reduction in the depth of the normalized transmittance valley in irradiated films was ascribed to the bleaching of carriers in the ground states due to their trapping in the defect states. The closed aperture Z-scan curves showed the presence of normalized pre-focal peak, followed by a valley, which is characteristic of the self-defocusing nonlinear refraction behaviour. The electron irradiation with different dose rates provided an opportunity to understand the variations in the optoelectronic properties of the ZnO thin films considering the various defect states generated upon irradiation.

Non-Linear Optical Properties of Nano Particle C60 Fullerene Using Lasers

The third order non-linear optical properties of Buckminster fullerene (C60) molecule has been studied using a Nd:YAG laser, in the visible and in the infrared region. The solvent using toluene was specifically used because of low threshold intensity for an optical limiter application. Closed aperture Z-scan technique was adopted to characterize the material due to its simplicity and high sensitivity in measuring the third-order optical nonlinearity. This allows computing the contributions of nonlinear absorption and nonlinear refraction towards nonlinearity. Saturable Absorption (SA) for C60 nano particles is also established. RSA is not established. FT-IR studies is also carried out to characterize the sample and to correlate the NLO studies.

The investigation of potassium tetra thiourea chloride on linear-nonlinear optical, electrical and mechanical properties of KDP crystal for NLO applications

ABSTRACTWe aimed to investigate the influence potassium tetra thiourea chloride (PTTC) on optical, dielectric and thermal properties of potassium dihydrogen phosphate (KDP) crystals. It was found that by addition of PTTC SHG efficiency has been enhanced. In addition, third order nonlinear properties have been studied by open and close aperture Z-scan technique. The enhanced LDT of grown crystal is found to be 2.08 GW/cm2. The dielectric response of grown crystal results lowers magnitudes. Thermal stability of grown crystal has been studied by TGA, DTA and DSC. The mechanical strength of doped crystals has been investigated by the Vickers microhardness studies and results are discussed.

Systematic analysis on linear and nonlinear optical traits of citrulline doped NH4H2PO4 (ADP) crystal

The current investigation is aimed to explore the optical properties of citrulline doped ammonium dihydrogen phosphate (NH4H2PO4,ADP) crystal by employing crystal growth, structural, UV–vis, Kurtz-Perry test and Z-scan characterization techniques. The growth of citrulline doped ADP single crystal has been achieved by slow solvent evaporation technique at ambient temperature. The pure and citrulline doped ADP crystals have been characterized by single crystal X-ray diffraction technique for structural analysis. The functional groups of grown crystal have been qualitatively identified by means of Fourier transform infrared analysis. The influence of citrulline on optical transmittance of ADP crystal has been evaluated within 200–900nm by means of UV–vis spectral analysis. The enhanced second harmonic generation (SHG) efficiency of citrulline doped ADP crystal has been determined using the Q-switched mode Nd:YAG laser and it is found to be 2.18 times higher than standard KDP crystal. The third order nonlinear optical (TONLO) behavior of citrulline doped ADP crystal has been investigated using He-Ne laser operating at 632.8nm. The close and open aperture Z-scan configuration has been used to evaluate the nature of TONLO refraction and absorption. The magnitude of TONLO parameters of citrulline doped ADP crystal has been determined using the Z-scan transmittance data. The potential liability of citrulline doped ADP crystal for optical applications has been discussed.