Order Nonlinear Optical Susceptibility Research Articles

New insights into non-linear optical properties, photocatalytic activity, and applications of ZnSe:Cu nanoparticles prepared by microwave-assisted hydrothermal method

In the present work, semiconducting ZnSe:Cu (0, 0.1, 0.75, 1.5, 2.25 and 3 mol%) nanoparticles (NPs) were prepared by microwave-assisted hydrothermal (MAH) method at the fixed pH of 11.2. XRD patterns certified the formation of nanocrystals with the size of about 2.04–2.21 nm. Also, FESEM and TEM images confirmed the formation of round-shape NPs. UV–Vis spectra showed that the energy gap of nanoparticles decreased from 3.615 to 3.342 eV by the increment in copper impurity content. The exact value of the energy gap of NPs was determined by the absorption spectrum fitting derivative method (DASF). Results revealed that these NPs have a high potential in optical and optoelectronic applications; specially, the samples owing 1.5 and 2.25 mol% of Cu-impurity, as the best candidates for optical fiber applications, showed the highest third order non-linear optical susceptibility (χ(3)). Also, for all synthesized NPs, the optical characteristics such as the optical transition index (m), Urbach energy (Etail), dielectric constant (ε) and the refractive index (n) at the absorption edge were determined. Moreover, the amount of metallization factor was also calculated, which decreases with the increase of impurity and microwave irradiation, indicating the increase of metal affinity of the samples. Photoluminescence (PL) spectra of ZnSe NPs demonstrated a general reduction in the intensity upon the introduction of Cu. This anticipated quenching further supports their heightened photocatalytic activity. The results of photocatalytic tests indicate that the sample containing 2.25 mol% of Cu exhibits the highest rate constant value (0.0255 min−1) and achieves the maximum efficiency (75.7 % after 60 min) for degrading the DB71, establishing it as the prime candidate for photocatalytic applications.

Integration of conventional surface science techniques with surface-sensitive azimuthal and polarization dependent femtosecond-resolved sum frequency generation spectroscopy.

Experimental insight into the elementary processes underlying charge transfer across interfaces has blossomed with the wide-spread availability of ultra-high vacuum (UHV) setups that allow the preparation and characterization of solid surfaces with well-defined molecular adsorbates over a wide range of temperatures. Within the last 15 years, such insights have extended to charge transfer heterostructures containing solids overlain by one or more atomically thin two dimensional materials. Such systems are of wide potential interest both because they appear to offer a path to separate surface reactivity from bulk chemical properties and because some offer completely novel physics, unrealizable in bulk three dimensional solids. Thick layers of molecular adsorbates or heterostructures of 2D materials generally preclude the use of electrons or atoms as probes. However, with linear photon-in/photon-out techniques, it is often challenging to assign the observed optical response to a particular portion of the interface. We and prior workers have demonstrated that by full characterization of the symmetry of the second order nonlinear optical susceptibility, i.e., the χ(2), in sum frequency generation (SFG) spectroscopy, this problem can be overcome. Here, we describe an UHV system built to allow conventional UHV sample preparation and characterization, femtosecond and polarization resolved SFG spectroscopy, the azimuthal sample rotation necessary to fully describe χ(2) symmetry, and sufficient stability to allow scanning SFG microscopy. We demonstrate these capabilities in proof-of-principle measurements on CO adsorbed on Pt(111) and on the clean Ag(111) surface. Because this setup allows both full characterization of the nonlinear susceptibility and the temperature control and sample preparation/characterization of conventional UHV setups, we expect it to be of great utility in the investigation of both the basic physics and applications of solid, 2D material heterostructures.

Effect of thermal poling in sodium tantalum phosphate glass-ceramics

Eu3+-doped sodium tantalum phosphate glass-ceramics containing bronze -like perovskite crystalline phase Na2Ta8O21 were obtained with different crystalline states (degree of crystallinity and average crystallite size) by a suitable control of the heat-treatment time and temperature of the precursor glass. Luminescence properties of Eu3+ in these materials are in agreement with a progressive insertion of the rare earth ions in the sodium tantalate Na2Ta8O21 phase, as probed by a clear decrease of the intensity ratio between transitions [5D0 →] 7F2/7F1 and narrowing of characteristic emission bands. Thermal poling insights were performed on these glassy and glass-ceramic materials and the experimental conditions had to be carefully optimized in the glass-ceramics to avoid electrical sparks and sample break associated with dielectric breakdown of the samples. Suitable and stable thermal poling treatments could be performed at 250 °C and 900 V under N2 atmosphere on both glass and glass-ceramics. These first insights pointed out a lower migration kinetic of sodium ions when compared to the precursor glass as well as a lower content of depleted ions, since part of sodium is supposed to be “frozen” inside the crystalline phase in glass-ceramics. Despite these lower kinetic poling conditions, a poled sodium depleted layer whose thickness depends on the poling time was successfully formed at the anode side. Reflectance infrared spectroscopy was also used to investigate the structural changes in the poled layer. These IR data pointed out that structural changes induced by thermal poling are mainly promoted in the phosphate network rather than tantalate units in both glass and glass-ceramics in agreement with a selective sodium migration from the remaining glassy phase. Macroscopic induced SHG measured by the Maker fringes technique is also consistent with the EFISH model and quantitative simulations of these data allowed to estimate second order nonlinear optical susceptibilities χ(2) ten to twenty times lower in the glass-ceramics than in the precursor glass. Such electric behavior is discussed in terms of dielectric properties of heterogeneous materials and interfacial polarization mechanisms between crystallites and glassy phase.

Effects of the magnetic field and the off-center displacement on the third-order nonlinear optical susceptibility of inverted core/shell spherical one-electron quantum dots

The third order nonlinear optical susceptibility (TONOS) of an inverted ZnS/CdSe core–shell spherical quantum dot embedded in SiO 2-matrix with or without impurity, and subjected to an external magnetic field is investigated. Within the framework of effective mass approximation and using B-splines basis functions, the energy levels, the dipole matrix elements and the TONOS are computed. The dielectric mismatch in the interface dots as well as the effective mass dependence on the core and shell regions are taken into account. It is revealed that, simultaneously the shell size, magnetic field and off-center displacement have a noticeable effect on the positions and the heights of the peaks of the TONOS. Moreover, we have shown that, due to the magnetic field and the off-center displacement effects, the TONOS takes different profiles associated with the polarization direction (parallel and perpendicular). In the perpendicular polarization, two peaks of the nonlinear optical properties appear for each off-center displacement value corresponding to the two transversal allowed transitions. The shift towards higher energies of the peak position and the reduction of the intensity of the peak when the magnetic field increases are recorded in the transversal transition case. Furthermore, in the longitudinal transition, as increasing the magnetic field strength, the intensity of the peak of the TONOS grows and the position of the peak is shifted towards lower frequencies. The dielectric constant, effective mass and conduction band offset of the materials that constitute the core and shell are equally found to modify significantly the main features of the susceptibility.

Study of Conditional Glass Formers (II) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers refer as (II) of group V(A,B) and VI(A,B). They are Ta2O5, Nb2O5, V2O5, Cr2O3, Bi2O3, TeO2, MoO3, As2O3, WO3, Se2O3. It is observed that on decreasing the values of optical electronegativity, optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index, third order non linear optical susceptibility increases. All conditional glass forming oxides (II) are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For Conditional glass formers (II) radius ratio rc/ra = 0.250-0.492, [except Bi2O3 (0.75) & TeO2 (0.87)] and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which would result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

STUDY OF GLASS FORMERS ON BASICS OF OPTICAL ELECTRONEGATIVITY

Concept of electronegativity is used by so many researchers to study Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study so many glass systems. Here the concept of optical electronegativity is used to study these parameters in glass formers. It is observed that on decreasing the values of optical electronegativity; optical band energy, metallization criterion, and bond ionicity decreases; where as optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All glass forming oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For glass formers radius ratio rc/ra = 0.14-0.40, [except P2O5] and single bond strength greater than 90 Kcal/mol. Key Words: Band energy, Basicity, Optical dielectric constant, Oxide ion polarizability, Refractive index.

Study of Conditional Glass Formers (I) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers referred as (1) taken from group III (A,B) and IV (A,B); they are Y2O3, HfO2, ZrO2, Sc2O3, TiO2, Al2O3, In2O3, Ga2O3, and SnO2. It is observed that optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All conditional glass formers (I) oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory, rules for formation of glass and Sun’s single bond strength theory. For conditional glass formers (I) radius ratio rc/ra = 0.40-0.75 and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

Synthesis, crystal growth and characterization of organic 1,2,4-triazole p-nitrophthalic acid (TPNP) single crystal for nonlinear optical (NLO) applications

The novel organic NLO single crystal 1,2,4-Triazole 4-nitrophthalic acid (TPNP) has been synthesised with methanol as a solvent in an equimolar ratio (1:1) by slow evaporation solution technique (SEST). The grown material was characterized for its NLO applications and reported for the first time. TPNP single crystal with the dimension of 10 mm × 5 mm × 4 mm was grown. The grown crystal was analysed through various characterization studies such as structural, optical, thermal, electrical and third harmonic generation (Z-scan) studies. The structural confirmation of the grown TPNP crystals was investigated by Single Crystal X-ray diffraction (SXRD) analysis. The Powder X-ray diffraction (PXRD) was used to identify the (h k l) planes for the purpose of drawing the morphology diagram of the original crystal image. The optical analysis carried out using UV–Vis-NIR study on TPNP crystal showed good optical transparency (80 %) and it can be used for various optical applications. To identify the structure and the functional groups, Fourier transform infrared (FTIR) study was conducted. Thermogravimetric and differential thermal analysis (TG-DTA) revealed the thermal stability of the grown TPNP crystal upto 155 °C. The surface etch pit density of TPNP crystal was carried out using chemical etching analysis. The negative photoconductive nature of title crystal was identified by photoconductivity analysis. The dielectric permittivity and dielectric loss as a function of frequency were measured for grown crystal. Intermolecular interactions and fingerprint plots of TPNP molecules are executed by Hirshfeld surface analysis. LDT of the title crystal was investigated by Q-switched Nd: YAG laser of wavelength 532 nm. Third order NLO parameters and susceptibility were determined using the Z-scan technique. It is concluded that the material can be effectively employed for various optoelectronic and photonic applications.

NLO azo compounds with sulfonamide groups: A theoretical investigation

The linear and nonlinear optical properties such as the dipole moment, polarizability, electric field–induced second harmonic generation, and hyper–Rayleigh scattering first hyperpolarizability of four heterocyclic azo compounds have been calculated and analysed extensively using density functional theory. The relationship between the structure, electric field–induced second harmonic generation, and hyper–Rayleigh scattering responses are evaluated. The relationship between the static first hyperpolarizability and energy gap is also taken into account. These azo compounds are found to have reduced HOMO-LUMO energy gap at the PBE0 level, large value of second order nonlinear optical susceptibility βHRS up to 2.8×102 a.u. was obtained at the same PBE0 level, and a significant donor character in the case of HAC2, HAC3 and HAC4 azo compounds, these factors render them suitable for nonlinear optical applications.

Structural, Hirshfeld surface analysis, third order non-linear optical and molecular modelling of imidazolium glutarate single crystals for optical applications

The Imidazolium glutarate (IMGA) single crystal was grown using a low-temperature solution growth method. The title crystal belongs to the triclinic crystal structure with space group P1. 13C and 1H nuclear magnetic resonance spectra were recorded to evaluate the environment of the title compound. The grown crystal (2 0 2) was orientated using powder X-ray diffraction (XRD) studies. The vibrational modes present in the title compound were confirmed through Fourier transform infrared (FT-IR) and FT-Raman spectral studies. The IMGA crystal is stable up to 150 °C and material weight loss occurs between 150 and 258 °C. The UV–Vis-NIR studies show that 75% transmission in the entire visible region. The crystals' dielectric loss and constant were calculated as a function of frequency. Intermolecular interactions and fingerprint plots of the IMGA were executed by the Hirshfeld Surface (HS) analysis. The theoretical nonlinear optical (NLO) properties like first-order hyperpolarizability and dipole moment have been studied. The 3rd order NLO susceptibility and related parameters have been studied by Z-scan measurement.

Prospects of non-linear optical behaviour of PZT/ZnO heterostructures

PZT and ZnO heterostructures were fabricated by using the sol-gel spin-coating method on two different substrates, viz., ITO-coated glass and Corning glass. UV–Vis spectroscopy of these heterostructures showed 80% transparency in the visible region of the electromagnetic spectrum, which is desirable for optical device applications. Tauc's relation was used to calculate the energy bandgap, which was found to be blue shifted to 3.96 eV in the case of the heterostructure on ITO-coated glass and 3.9 eV for that on Corning glass, indicating a difference of ΔE = 0.06 eV due to the change in substrate. The refractive index (n), extinction coefficient (k), and the real and imaginary parts of the dielectric constant (ε1 and ε2) of the heterostructures were estimated. The second order non-linear refractive index (n2) and the third order non-linear optical susceptibility (χ(3)) were determined by generalized Miller's rule in the photon energy range of 0.5–6.5 eV by using the UV–Vis spectroscopic data. The respective values of χ(1) and χ(3) values were found to be in the range 0.10–0.45 and 3.88 × 10−13–6.0 × 10−12. The optical and structural studies established that the nanocrystalline PZT-ZnO heterostructure on ITO-coated glass was more optically transparent and had better non-linear properties as compared to that on the corning glass substrate. These properties are advantageous for optoelectronic device applications.

The additional optical angular momentum flux in media with nonlocality of nonlinear optical response

The additional terms caused by the nonlocality of the nonlinear optical response of the medium in the expressions for the optical angular momentum density, the optical angular momentum flux density and the torque density on light, which are related to each other by the angular momentum transformation law, are obtained as a consequence of peculiarities of the momentum conservation law in such media. It is shown that the manifestation of the nonlocality of the optical response only changes the form of polarization of medium included in the expression for the angular momentum density, whereas the definition of the angular momentum flux density contains additional term depending on the nonlocal nth order nonlinear optical susceptibility.

Growth and characterization of nitrophenol complexes with piperazine and pyridine derivatives

1-amino-4-methyl piperazine bis (4-nitrophenol) (1A4MP4N) and 2-amino-5-methyl pyridinium 4-nitrophenolate 4-nitrophenol (2A5MP4N) have been grown as single crystals using slow evaporation solution growth technique at room temperature. The grown crystals were characterized by single crystal X-ray diffraction and its lattice parameters were determined. 1A4MP4N and 2A5MP4N were crystallized in monoclinic crystal system with P21/n and Cc space group respectively. In 1A4MP4N, piperazine ring possesses inversion symmetry and has a chair conformation. Piperazine ring linked to 4-nitrophenol molecule through O3-H3D···N2 hydrogen bond forms C(5) chain motif. In 2A5MP4N, N1 atom in 2-amino-5-methyl pyridinium cation is connected with 4-Nitrophenolate anion through N1-H1···O11 hydrogen bond thus forms C(12) chain motif. Hirshfeld surface mapping analysis is carried out for both crystal structures. The fingerprint plot for H···H intermolecular contacts cover a major portion (41 %) of the Hirshfeld area of 1A4MP4N and O···H (35.7%) intermolecular contacts play a major role in 2A5MP4N. The Taucs plot reveals that band gaps of 1A4MP4N and 2A5MP4N are 2.66 eV and 5.18 eV respectively. From Z-scan technique the third order nonlinear optical susceptibility is found to be χ3 = 1.21322 × 10−9 esu and 1.75752 × 10−9 for both crystals.

Structure dependent third order nonlinear susceptibility in the presence of impurity and magnetic field in CdS/ZnS core/shell quantum dot

Third order nonlinear optical susceptibility due to intersubband optical transition of an electron confined in a CdS/ZnS core-shell quantum dot is investigated for various sizes of core and shell radii in the presence of magnetic field. It is computed by employing the variational approach within the effective mass approximation and the two level density matrix method is applied to obtain the transition energy between two levels. The dependence on third order susceptibility of the incident light is investigated. The results show that the third order nonlinear optical susceptibility is blueshifted with the reduction of inner core radius for a constant outer radius and the same trend is observed with the decreasing outer shell radius. The resonant wavelength and the peak of third order susceptibility will be managed by the control over the structure of core-shell materials and the external perturbation.

Influence of Ni doping on the structural and third order nonlinear optical properties of ZnMoO4 nanostructures

We report the third order nonlinear optical properties of Ni doped ZnMoO4 nanostructures with various concentration of Ni. The structural, optical and morphological properties have been investigated. X-ray diffraction pattern confirmed the successful incorporation of Ni into ZnMoO4 lattice without any secondary phase formation. The optical absorption spectra revealed a slight shift of absorption edge towards longer wavelength with an additional band appeared at 440 nm upon Ni doping. The variation of nonlinear optical properties of the synthesized nanostructures under continuous wave laser was investigated by a Z-scan technique at 532 nm. Experimental results reveal that the nanostructures exhibit reverse saturable absorption and negative nonlinearities. The measured third order nonlinear optical susceptibility was found to be in the order of 10−6 esu. Based on the observed results it is suggested that the nonlinear optical characteristics of the nanostructures could be controlled by Ni doping making them a potential candidate for optical device applications.

Effect of molar concentration on the structural, linear and nonlinear optical properties of CuS (covellite) thin films

CuS thin films with various molar concentrations at 70 °C temperature were deposited by Chemical Bath Deposition. The effect of molar concentration on the structural, linear optic, nonlinear optic and morphological properties of CuS films were deeply investigated. X-ray diffraction (XRD) analysis exhibited that CuS films were formed in polycrystal structure and hexagonal phase. The fundamental optical parameters of films such as energy band gap, reflection and extinction coefficient were determined with the results of optical transmission and optical absorption by UV–vis spectrophotometer. The energy band gap values were reduced with increasing films thickness. Moreover, the dependence of the optical dielectric constants, loss tangent, optical conductivity, surface and volume energy loss function values on the molar concentrations were studied. Furthermore, the third order nonlinear optical susceptibility and nonlinear refractive index, which is considered to be the base of the first order optical susceptibility with nonlinear optical properties were discussed in detail.

Structural, physical and optical properties of ZnO-V2O5-P2O5 glass system

ZnO-V2O5-P2O5 glasses were synthesized by the melt-quenching technique. Fourier transformed infrared spectra reveal unshared vanadium-oxygen bonds, resulting in an increase in non-bridging oxygen bonds in the glass network. The densities of the samples were decreased from 3.112 to 2.240 g.cm−3, while the molar volumes were increased from 37.827 to 54.349 cm3.mol−1. The optical band gap of the base glass is determined to be 2.492 eV and this value was reduced to be 1.919 eV at the maximum addition of V2O5 content. The refractive index values were found to grow as the vanadium content rose. Both the optical band gap and refractive index values were discussed in the view of non-bridging oxygen formation within the glass matrix. Oxideion polarizability and interaction parameter were investigated for the glass samples.Theoretical optical basicity values of the investigated glasses were found to range between 0.399 and 0.407, indicating the tendency of oxide ionsto donate electrons to cations. The prepared glasses have high values of the optical basicity (1.077–1.267), third order non-linear optical susceptibility (0.625–1.364×10−11 esu), electronic oxide ion polarizability (2.816–4.143 Å3), and metallization criterion (0.353–0.310), implying that they can be used in non-linear optical applications.

Femtosecond excited-state dynamics and ultrafast nonlinear optical investigations of ethynylthiophene functionalized porphyrin

Ethynylthiophene functionalized D-π-A porphyrin (LG5) belongs to a class of porphyrin molecules with proven application in organic solar cell devices. In this report, we present a comprehensive optical and non-linear optical characterization of ethynylthiophene functionalized porphyrin molecule, denoted as LG5. Femtosecond transient absorption (TA) spectroscopy was used to study the ultrafast excited-state properties with 400 nm, 70 fs photoexcitation. Global and target fitting analysis of the obtained TA spectra established a reliable photophysical model of excited state population relaxation and extracted the various rate constants. Considering the good performance of LG5 as a photosensitizer in dye-sensitized solar cells (DSSCs), electron injection studies on LG5 sensitized mesoporous TiO2 were also performed. Both integrated and transient photoluminescence (PL) data for LG5 sensitized TiO2 samples confirms efficient electron injection. The target analysis on TA data of LG5–TiO2 films revealed a multi-step electron injection from different excited energy levels with both ultrafast (≈370 fs) and slow injections times. Additionally, the non-linear optical (NLO) properties of LG5 are studied using the single-beam Z-scan technique upon photoexcitation of 800 nm, 70 fs laser pulses. The open aperture data demonstrated two-photon absorption (2PA), and closed aperture data indicated the presence of positive nonlinear refraction. The calculated values of 2PA cross-section and 3rd order NLO susceptibility were 1723 GM and 1.89 × 10−13 esu (2.64×10−21m2V−2), respectively.

An investigation on structural, optical and enhanced third order nonlinear optical properties of facilely synthesized Ce:CuS nanosheets

Current work reported facile chemical synthesis of hexagonal covellite CuS nanostructures with 0.0, 1.0, 3.0 and 5.0 wt% cerium doping concentrations. Scherrer’s equation used to determine the crystallites size and preferred orientation of growth plane is found along (110). Raman spectra of CuS nanostructures showed the characteristics sharp peak at the ∼ 472.21 cm−1. SEM images revealed the shape of nanostructures as nanosheets (NSs) for Ce:CuS. The band gap values of Ce:CuS NSs was computed from diffuse reflectance spectra (DRS) using Kubelka-Munk (K-M) theory which was found in range of 1.56–1.85 eV. Red and UV emission band of nanostructures can be seen in Photoluminescence spectra clearly. Third order nonlinear optics were performed by Z-scan techniques via femtosecond fiber pulsed laser. The nonlinear absorption coefficients (β) and nonlinear refractive index (n2) were found in range of 1.14 × 10-8–2.04 × 10-8 cm/W and 1.04 × 10-12–1.38 × 10-12 cm2/W, respectively. The value of third order nonlinear optical susceptibility (χ(3)) was noticed ∼ 3.36 × 10-8–5.48 × 10-8 esu. A significant improvement was observed in χ(3) with Ce incorporation in CuS lattice system. Therefore, Ce doping makes CuS potential nonlinear optical material for modern photonics device applications.

A comprehensive study on structure, opto-nonlinear and photoluminescence properties of Co3O4 nanostructured thin films: An effect of Gd doping concentrations

Cobalt oxide (Co3O4) thin films with 0, 1.0, 3.0 and 5.0 wt% Gd doping concentrations were fabricated on glass substrates by spray pyrolysis method. X-ray diffraction pattern (XRD) of as-deposited thin films confirm spinel structure growth oriented along (311) plane. Crystallite sizes of the grown films decreases with the increase in Gd doping concentrations and found in range of ∼17.7–7.2 nm. Raman investigation of films further approves spinel growth of cobalt oxide films. Surface morphology of pure and Gd: Co3O4 thin films were analyzed using field emission scanning electron microscopy (FESEM) with round shape particles at nanoscale. Chemical compositions, elements, and their stoichiometry were observed by energy dispersive spectra (EDX). Tauc's plots of films clearly shows two direct optical band gaps, (1) in the range of 1.49–1.52 eV and (2) in the range of 2.01 eV–2.58 eV respectively. A significant impact of Gd doping was observed on second optical band gaps, which increases with Gd contents. Room temperature (RT) dependent photoluminescence (PL) spectra of the deposited films showed that emission peaks at 363, and 753 nm under excitation wavelength of 240 and 500 nm respectively. The third order nonlinear optical susceptibility χ(3) and nonlinear refractive n(2) which were calculated and found in range 4.46 × 10−13- 2.25 × 10−10 esu and 1.01 × 10−10-2.39 × 10−9 esu., respectively.