Dye-doped Polymer Film Research Articles

High-performance dichroic dye-doped flexible cholesteric polymer film optical filter for laser protection application.

High-performance optical filters are quite useful in laser protection application that is critical in military and civilian fields for protection of human eyes and photonic devices. However, most existing technologies are often angle-dependent and complicated, which hinder the useful range of real-time application. Here, we report the development of a dichroic dye-doped flexible cholesteric polymer film optical filter with double-layer structure consisted of two films with opposite handedness for laser protection application. The fabricated films exhibit high and stable optical density (>4.6) in large angle range from 0 to 70°, indicating a good angle-independence. The proposed films show excellent stability in a broad temperature range from -100 °C to 100 °C, and high mechanical stress up to 9.8 × 105 Pa. As a laser protection, the optical filter can resist pulse pump energy up to 110 mJ/pulse, showing a high damage threshold. The flexible and free-standing film optical filters as laser protection device are integrated by simple fabrication, excellent stability to temperature and mechanical stress, angle-independence, high optical density, and good visibility simultaneously, showing dramatically application potential in laser protection and other flexible photonic devices.

Real-time observation of structural change in semi-crystalline polymer films through mid-IR transmission spectroscopy: determination of instantaneous film temperature during recrystallization.

We report the real-time observation of entire structural change in dye-doped semi-crystalline polymer (polyethylene) films through mid-IR transmission spectroscopy. The laser-heated dye molecules heat the polymer film through thermal diffusion, and accordingly the polymer film undergoes the structural change from the crystalline to amorphous structures, which is followed by the reverse structural change, namely recrystallization, during the natural cooling. By tuning the mid-IR probe pulse to one of the few structure-sensitive vibrational modes and varying the time delay between the pump and probe pulses we can monitor the structural change of the polymer film and time-varying film temperature during recrystallization through the transmission change of the resonant mid-IR probe pulse with the time-resolution of sub-μs.

Third - Order Nonlinear Optical Properties and Optical Limiting Behavior of Celestin Blue B Dye Doped Polymer Films

Pure Poly (methylmethacrylate) (PMMA) polymer film and Celestin Blue B dye doped polymer films at different concentrations were prepared using casting technique. UV - Vis spectra were recorded to characterize the optical properties of the Celestin Blue B dye doped PMMA polymer films. The magnitudes of both real and imaginary parts of third - order nonlinear susceptibility (χ (3)) of Celestin Blue B dye doped polymer films were determined using the z - scan technique with a continuous wave laser beam at wavelength 532 nm. The nonlinear refractive index (n2) and the nonlinear absorption coefficient (β) of the Celestin Blue B dye doped polymer films were calculated. It was found that the prepared films exhibited saturable absorption (SA) and self - defocusing effect. The optical power limiting behavior also investigated for Celestin Blue B dye doped PMMA polymer films at different concentrations and the optical power limiting threshold values were determined. Results indicate that the Celestin Blue B dye doped PMMA polymer film is a promising material for future photonic device applications.

From Insulating PMMA Polymer to Conjugated Double Bond Behavior: Green Chemistry as a Novel Approach to Fabricate Small Band Gap Polymers.

Dye-doped polymer films of Poly(methyl methacrylate) PMMA have been prepared with the use of the conventional solution cast technique. Natural dye has been extracted from environmentally friendly material of green tea (GT) leaves. Obvious Fourier transform infrared (FTIR) spectra for the GT extract were observed, showing absorption bands at 3401 cm−1, 1628 cm−1, and 1029 cm−1, corresponding to O–H/N–H, C=O, and C–O groups, respectively. The shift and decrease in the intensity of the FTIR bands in the doped PMMA sample have been investigated to confirm the complex formation between the GT dye and PMMA polymer. Different types of electronic transition could be seen in the absorption spectra of the dye-doped samples. For the PMMA sample incorporated with 28 mL of GT dye, distinguishable intense peak around 670 nm appeared, which opens new frontiers in the green chemistry field that are particularly suitable for laser technology and optoelectronic applications. The main result of this study showed that the doping of the PMMA polymer with green tea dye exhibited a strong absorption peak around 670 nm in the visible range. The absorption edge was found to be shifted towards the lower photon energy for the doped samples. Optical dielectric loss and Tauc’s model were used to estimate the optical band gaps of the samples and to specify the transition types between the valence band (VB) and conduction band (CB), respectively. A small band gap of around 2.6 eV for the dye-doped PMMA films was observed. From the scientific and engineering viewpoints, this topic has been found to be very important and relevant. The amorphous nature of the doped samples was found and ascribed to the increase of Urbach energy. The Urbach energy has been correlated to the analysis of X-ray diffraction (XRD) to display the structure-properties relationships.

Investigation of Optical Properties of Solochrome Dark Blue Dye Doped Polymer Films

The optical properties of the pure poly(methylmethcrylate) (PMMA) polymer film and PMMA polymer films doped with Solochrome Dark Blue dye at different concentrations were investigated. The films were prepared using the casting technique. The optical absorption and transmission spectra of these films were recorded in the wavelength range 300 - 900 nm for different concentrations using UV-Vis double - beam spectrophotometer. The optical parameters of the Solochrome Dark Blue dye - doped polymer films, reflectance (R), absorption coefficient (α), extinction coefficient (κ), refractive index (n), optical and electrical conductivities (σopt and σelect), and optical energy band gap (Eg), were calculated. The effect of the dye concentration on these parameters was studied. The obtained results show that the Solochrome Dark Blue dye is a promising material for applications in photonic and optoelectronic devices.

Study of Nonlinear Optical Properties of Disperse Yellow – 7 Dye-doped Polymer Films using CW Laser

The materials with an ability of self-focusing/defocusing through their light intensitydependent refractive index and phase shift properties are potential candidates for all-optical photonic devices. Several organic materials including dye-doped polymer films are attracting many researchers due to their advantages in terms of enhanced efficiency, and acceptable mechanical properties to fabricate useful devices. In this paper, we have reported the nonlinear optical properties like nonlinear absorption and nonlinear refraction of an organic dye Disperse Yellow - 7 (DY-7) doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix using open aperture and closed aperture Z-scan experimental methods by means of low power continuous wave (CW) laser beam. The optical limiting properties of these films are also studied using Type 1 and Type 2 configurations at different input powers using continuous wave (CW) laser beams of 532 nm wavelength. The nonlinear refractive index n2, nonlinear absorption coefficient β, changes in refractive index with input intensity, and the magnitude of third-order optical nonlinearity of the dye-doped film are experimentally determined. The sample is tested for optical power limiting in which the input limiting threshold and saturated output power level for both type 1 and type 2 optical limiting configurations are recorded. DY-7 dye-doped in PMMA-MA polymer film has shown saturation absorption at lower input irradiance and reverse saturation absorption at higher input irradiance along with thermal nonlinearity and hence found to be a potential candidate for the third harmonic property based photonic devices.

Study of Third Order Optical Nonlinearity in Disperse Orange-25 Dye-doped Polymer Films using CW Laser

The organic materials with the ability of self-focussing/defocusing through their light intensity-dependent refractive index and phase shift properties are potential materials in alloptical photonic devices have become interesting topic of continuous research. Several organic materials including dye-doped polymer films are attracting many researchers due to their advantages in terms of enhanced efficiency, and acceptable mechanical properties tofabricate useful devices. In this paper, we have reported the nonlinear optical properties like nonlinear absorption and nonlinear refraction of an organic dye Disperse Orange-25 (DO-25) doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix usingopen aperture and closed aperture Z-scan experimental methods by means of low power continuous wave (CW) laser beam. The optical limiting properties of these films are also studied using Type 1 and Type 2 configurations at different input powers using continuous wave (CW) laser beams of 532 nm wavelength. The nonlinear refractive index n2, nonlinear absorption coefficient β, changes in refractive index with input intensity, and the magnitude of third-order optical nonlinearity of the dye-doped film are experimentally determined. The saturated output power for type 1 and type 2 optical limiting are determined. The inputlimiting threshold and saturated output power level for both type 1 and type 2 optical limiting configurations are recorded. DO-25 dye-doped in PMMA-MA polymer film has shown saturation absorption at lower input irradiance and reverse saturation absorption at higher input irradiance and hence found to be a potential candidate for the third harmonic property based photonic devices.

Study of Third Order Optical Nonlinearity in Disperse Orange-25 Dye-doped Polymer Films using CW Laser

The organic materials with the ability of self-focussing/defocusing through their light intensity-dependent refractive index and phase shift properties are potential materials in alloptical photonic devices have become interesting topic of continuous research. Several organic materials including dye-doped polymer films are attracting many researchers due to their advantages in terms of enhanced efficiency, and acceptable mechanical properties to fabricate useful devices. In this paper, we have reported the nonlinear optical properties like nonlinear absorption and nonlinear refraction of an organic dye Disperse Orange-25 (DO-25) doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix using open aperture and closed aperture Z-scan experimental methods by means of low power continuous wave (CW) laser beam. The optical limiting properties of these films are also studied using Type 1 and Type 2 configurations at different input powers using continuous wave (CW) laser beams of 532 nm wavelength. The nonlinear refractive index n2, nonlinear absorption coefficient β, changes in refractive index with input intensity, and the magnitude of third-order optical nonlinearity of the dye-doped film are experimentally determined. The saturated output power for type 1 and type 2 optical limiting are determined. The input limiting threshold and saturated output power level for both type 1 and type 2 optical limiting configurations are recorded. DO-25 dye-doped in PMMA-MA polymer film has shown saturation absorption at lower input irradiance and reverse saturation absorption at higher input irradiance and hence found to be a potential candidate for the third harmonic property based photonic devices.

Photovoltaic effect in dye-doped polymer films with free-surface and sandwich structures

Photovoltaic properties of the polymer composite films doped with cationic, anionic and neutral polymethine dyes were investigated. It was revealed that the magnitude and even the sign of photovoltaic effect change in going from the free-surface to sandwich structures. It was shown that in free-surface samples the photo-emf sign is determined by the nature of polymer and dye. By contrast, in sandwich structures the photo-emf sign does not depend on composition of the photoactive layer and is governed by drift of the photogenerated charge carriers in the electric field formed by different work function of the electron- and hole-collecting contacts.

Linearly and circularly polarized laser photoinduced molecular order in azo dye doped polymer films

Photo-induced behavior of Azo Disperse one (AZD1) doped Poly(Methyl MethAcrylate) (PMMA) using both linear and circular polarized light is studied. The anisotropy is not erased by the circular polarization light. The circular polarization light combined with relatively long lifetime of the cis state in azo dye doped polymers activate all transverse directions of the angular hole burning through the spot in the film inducing anisotropy. Under circular polarized light, there is no orientation perpendicularly to the helex described by the rotating electric field vector, trans molecules reorients in the propagation direction of the pump beam. The polarization state of the probe beam after propagation through the pumped spot depends strongly on the angle of incidence of both pump and probe beams on the input face. In the case where circular polarized pump and probe beams are under the same angle of incidence, the probe beam “sees” anisotropic film as if it is isotropic. Results of this work shows the possibility to reorient azobenzene-type molecules in two orthogonal directions using alternately linearly and circularly polarized beams.

CW Optical Limiting Study in Disperse Yellow Dye-doped PMMA-MA Polymer Films

<div><p><em>Molecules with high two-photon absorption (TPA) cross section and the molecules which have reverse saturation absorption (RSA) cross section are of great interest today because of their application in three-dimensional optical data storage and photonic switches. During last forty years, several techniques have been developed to determine the two-photon absorption cross-sections and reverse saturation absorption cross-sections of the materials. This includes direct methods, such as nonlinear transmission and Z-scan methods and indirect methods, such as two-photon excited fluorescence and two-photon pump-probe transient absorption spectroscopy. During recent years, the organic dye-doped polymer films getting more attention due to their advantages to fabricate photonics devices. In this paper, we have studied the nonlinear optical properties like nonlinear absorption and nonlinear refraction of an azo dye Disperse yellow-7 (DY-7) doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix using open aperture and closed aperture Z-scan experimental methods using continuous wave (CW) laser. The optical limiting properties of these films are also studied in Type 1 and Type 2 configurations at different input power using continuous wave (CW) laser beams of 532 nm wavelength.</em></p></div>

TYPE 1 & TYPE 2 OPTICAL LIMITING STUDIES IN DISPERSE ORANGE-25 DYE-DOPED PMMA-MA POLYMER FILMS USING CW LASER

Materials with exceptional third-order nonlinear optical properties are critical to the continuing development of photonics and electro-optical devices such as those used in optical communications, networking, the optical computation for signal processing, and data storage devices. The nonlinear optical material research is generally focussed on improving the efficiency of optical wavelength conversion, optical amplification, nonlinear absorption, refractive index changes etc. which are input light intensity dependent. During last few years, the organic dye-doped polymer films are getting more attention due to their advantages in fabricating optimum photonics devices. In this paper, we have studied the nonlinear optical properties like nonlinear absorption and nonlinear refraction of an azo dye Disperse Orange-25 (DO-25) doped in Polymethyl methacrylate-methacrylic acid (PMMA-MA) polymer matrix using open aperture and closed aperture Z-scan experimental methods for continuous wave (CW) laser input. The optical limiting properties of these films are also studied using Type 1 and Type 2 configurations at different input power using continuous wave (CW) laser beams of 532 nm wavelength.The nonlinear absorption coefficient, nonlinear refractive index, and saturated output power for type 1 and type 2 optical limiting are determined.

Plasmonic enhancement of random lasing from dye-doped polymer film by bristled Ag/TiO_2 composite nanowires

We report on the enhanced random lasing from an organic gain medium in a planar waveguide, with the assistance of bristled Ag/TiO2 composite nanowires. Tris(8-hydroxyquinolinato)aluminum (Alq3) and 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) are used as donor-acceptor lasing dyes. Comparing to the gain medium with silver nanowires, the lower lasing threshold is achieved utilizing bristled Ag/TiO2 nanowires, and the threshold is reduced by 3.7 times than that of the neat gain medium. It is attributed to the broader localized surface plasmon resonance spectrum of Ag/TiO2 nanowires which could sufficiently overlap with both absorption and emission spectra of donor-acceptor lasing dyes, the stronger localized electric field enhancement effect and scattering effect. In addition, the unique plasmonic waveguide effect could also contribute to the enhanced lasing and lead to the lower lasing threshold. This method is expected to be a potential metal-modified technology for improving the lasing performance.

Photoassisted Holography in Azo Dye Doped Polymer Films.

Holographic storage is one of the most important applications in the field of optics, especially for recording and retrieving data, and information storage by interference patterns in photosensitive materials are no exception in this regard. In this work, we give evidence that holograms recorded by interference of two coherent laser beams in azo dye doped polymer films can be controlled by a third incoherent assisting laser beam. We show that light diffraction can be increased or decreased by an assisting beam depending on the respective orientation of the polarizations of the recording and the assisting beams. We also found that photomanipulation of polarization holograms, prepared by polarization modulation, does not depend on the polarization of the assisting beam, whereas, photomanipulation of holograms prepared by intensity modulation strongly depends on the polarization of the assisting beam. Photoselection is shown to play a major role in the photoassisted diffraction process.

ABCD analysis of Dye doped Polymers for Photonic Applications

Photonics is a subject of scientific study on generating, controlling, harvesting and detecting the beam of photons or light with a purpose of creating, manipulating, storing, transmitting and detecting information using nonlinear optical properties of materials. This paper is a new attempt to integrate scientific research and social research by analysing the characteristics of dye-doped polymer films for photonics applications. The analysing framework called ABCD framework to analyse any business concepts, business systems, technology, strategy, engineering material, technology or even an idea systematically by identifying the advantages, benefits, constraints, and disadvantages under various determinant issues and listing the constituent critical elements under each construct. In this paper, as per the ABCD framework, the various determinant issues related to the use of dye-doped polymer films for photonic applications through focus group method are determined as affecting factors under: (1) Material Issues, (2) Application Issues, (3) Commercialization Issues, (4) Production/Service providers Issues, (5) Customer Issues, and (6) Environmental/Social Issues. The constituent critical elements of these factors are listed under the four constructs - advantages, benefits, constraints and disadvantages of the ABCD technique and tabulated. The analysis has brought about 204 critical constituent elements which satisfy the success of this analysis methodology.

A Polymer Film Dye Laser with Spatially Modulated Emission Controlled by Transversely Distributed Pumping

Spatial modulation of laser emission controlled by the structure of excitation light field was demonstrated. A dye doped polymer film as an active medium was sandwiched between two laser mirrors forming a laser cell. The pumping was performed by an interference pattern formed with two mutually coherent beams of the second harmonic of a Q-switched Nd:YAG laser (532 nm) and located in the plane of the laser cell. The laser emission was observed normally on the plane of the cell. The cross section of the obtained laser emission was modulated in intensity with an interval between maximums depending on the period of the pumping interference pattern. Thus, the emitted light field qualitatively looks like diffraction from an elementary dynamic hologram, that is, a holographic diffraction grating.

ABCD analysis of Dye-doped Polymers for Photonic Applications

<div><p><em>Photonics is a subject of scientific study on generating, controlling, harvesting and detecting the beam of photons or light with a purpose of creating, manipulating, storing, transmitting and detecting information using nonlinear optical properties of materials. This paper is a new attempt to integrate scientific research and social research by analysing the characteristics of dye-doped polymer films for photonics applications. The analysing framework called ABCD framework to analyse any business concepts, business systems, technology, strategy, engineering material, technology or even an idea systematically by identifying the advantages, benefits, constraints, and disadvantages under various determinant issues and listing the constituent critical elements under each construct. In this paper, as per the ABCD framework, the various determinant issues related to the use of dye-doped polymer films for photonic applications through focus group method are determined as affecting factors under : (1) Material Issues, (2) Application Issues, (3) Commercialization Issues, (4) Production/Service providers Issues, (5) Customer Issues, and (6) Environmental/Social Issues. The constituent critical elements of these factors are listed under the four constructs - advantages, benefits, constraints and disadvantages of the ABCD technique and tabulated. The analysis has brought about 204 critical constituent elements which satisfy the success of this analysis methodology. <strong></strong></em></p></div>

Localized surface plasmon resonance improved lasing performance of Ag nanoparticles/organic dye random laser

Random lasing threshold reduction and emission enhancement were reported from a suspension of Ag nanoparticles (NPs) in a laser dye doped polymer film. To evaluate the effect of the localized surface plasmon resonance (LSPR) of metal NPs on random lasing from lasing dye, we carry out a comparative study of the random lasing performance of the Ag NPs and SiO2 NPs scattered dye doped polymer films. Random lasing emission was obtained from Ag NPs and SiO2 NPs scattered dye doped polymer films. The threshold was dramatically reduced from 0.01 to 0.003 mJ/pulse as Ag NPs was used as scatters instead of SiO2 NPs. Theoretical simulation indicates that a large localized electric field is built near the Ag particle surface which enhances the absorption of excitation light. Furthermore, excellent overlap of the plasmonic resonance of Ag NPs with the absorption and photoluminescence spectrum of the dye molecules promotes more dye molecules excited simultaneously to the higher energy levels and leads to more effective random lasing performance.

Random lasing based on rough dye-doped polymer thin film

In this work, a random laser action from rough dye film processed by surface rubbing with flannelette is reported. For the dye-doped polymer films with high surface roughness by surface rubbing, laser mode is stable, and threshold energy is found to be very low that is 333 μJ/cm2. By analyzing the random lasing spectrum using power Fourier transforms, an average resonator length was estimated as about 18.99 μm, which is 6.4 times larger than the film thickness. Furthermore, the influence of the concentration of Pyrromethene 597 (PM597) on the random laser was studied, and the results indicate that there is an optimum concentration for achieving the lowest threshold. Compared with glass groove structure with the dye doped film, the random laser based on the rough structure has reasonable time stability. This microstructure type random laser reported in this work is in low cost and easy to make compared with other laser structures of this category.

Nonlinear optical properties and optical power limiting effect of Giemsa dye

The nonlinear optical properties of Giemsa dye in chloroform solution for different concentrations and dye mixed with poly(methylmethacrylate) (PMMA) as a dye-doped polymer film were investigated using continuous wave (CW) low power solid-state laser (SSL) operating at wavelength of 532nm as an excitation source. Using the single beam z-scan technique, the nonlinear refractive index (n2), the nonlinear absorption coefficient (β), and the third-order nonlinear optical susceptibility (χ(3)) of Giemsa dye were measured. The measurements reveal that both n2 and β are dependent on the dye concentration. The obtained results indicate that the Giemsa dye exhibits positive nonlinear saturable absorption (SA) and negative refraction nonlinearity, manifestation of self-defocusing effect. Optical power limiting characteristics of the Giemsa dye at different concentrations in solution and polymer film were studied. The observed large third-order optical nonlinearity of Giemsa dye confirms that Giemsa dye is a promising nonlinear material for the optical power limiting and photonic devices applications.