Photopolymer Recording Materials Research Articles

Holographic Multi-Notch Filters Recorded with Simultaneous Double-Exposure Contact Mirror-Based Method

This study presents a novel simultaneous double-exposure contact mirror-based method for fabricating holographic multi-notch filters with dual operational central wavelengths. The proposed method leverages coupled wave theory, the geometric relationships of K-vectors, and a reflection-type recording setup, incorporating additional reflecting mirrors to guide the recording beams. To validate the approach, a holographic notch filter was fabricated using photopolymer recording materials, resulting in operational wavelengths of 531.13 nm and 633.01 nm. The measured diffraction efficiencies at these wavelengths were ηs = 52.35% and ηp = 52.45% for 531.13 nm, and ηs = 67.30% and ηp = 67.40% for 633.01 nm. The component’s performance was analyzed using s- and p-polarized spectral transmission intensities at various reconstruction angles, revealing polarization-independent characteristics under normal incidence and polarization-dependent behavior under oblique incidence. The study also explored the relationships between recording parameters, such as incident angle, wavelength, emulsion expansion, and dispersion. The findings demonstrate that the first operational central wavelength is primarily influenced by the recording wavelength, while the second is primarily determined by the incident angle, covering a range from visible light to near-infrared. This method offers significant potential for cost-effective, mass-produced filters in optoelectronic applications.

Characterization of two ultraviolet–blue volume-phase holographic gratings based on dichromated gelatin and photopolymer recording materials

Characterization of two ultraviolet–blue volume-phase holographic gratings based on dichromated gelatin and photopolymer recording materials

Complex method for angular-spectral analysis of volume phase diffraction gratings recorded in photopolymers

Photopolymer recording materials are nowadays widely used for recording of diffraction gratings and other diffraction elements. For obtaining the best performance of these diffraction gratings for desired applications, it is important to assess these gratings from many different perspectives. In this contribution, we present an experimental and characterization approach to an analysis of diffraction gratings recorded into photopolymer materials. This approach is able to provide a complex and very illustrative description of these gratings response and, with accordance to the theory, information about some important grating parameters, such as a spatial period, slant angle, etc., as well. This approach is based on the measurement of a grating response for a wide range of angles and wavelengths and then on the construction and subsequent analysis of maps in the angular-spectral plane. It is shown that the measurements are in a good agreement with the theoretical predictions based on either approximate (Kogelnik’s coupled wave theory) or rigorous (RCWA) techniques and that this approach provides complex and detailed characterization of the grating response which can be used for additional optimization or decision of applicability of measured sample gratings.

Real-time measurements of diffraction grating growth in photopolymer recording materials

Self-developing ability of photopolymer recording material enables measurements of growth of a refractive index grating in the real-time during a holographic exposure. In our laboratory, we prepare thin layers of photopolymer recording materials and measure their response on harmonic interference field. The results of the measurements are used for characterization of the recording process running in photopolymers and optimization of their chemical composition. Recently, the detection setup has been adapted to measure the phase shift between the recording interference field and the refractive index grating simultaneously with the grow-curves. The phase shift measurement is especially important in the case of photopolymers with nanoparticles as they are spatially redistributed within the layer during the holographic exposure. In the paper, we introduce the principles of the measurement technique, describe our exposure and detection setup, analyze the grow-curve, and show some results obtained from our measurements of the newly developed photopolymer with AgBr nanoparticles.

표면 부조 홀로그램 마스크를 이용한 내부전반사 홀로그래픽 노광기술

내부전반사 홀로그래픽 노광 기술은 넓은 면적(6")을 아주 미세하게(<TEX>$0.35{\mu}m$</TEX>) 노광할 수 있는 차세대 광 노광 기술로서 평가받고 있다. 기존의 광 노광 기술은 <TEX>$1.5{\mu}m/6}$</TEX> 이상이 가능한 (LCD용 노광기)과 <TEX>$0.2{\mu}m/1.5"$</TEX> 이하(반도체용 노광기)의 패턴을 노광할 수 있도록 양분되어 발전하여 왔다. 이에 반하여 내부전반사 홀로그래픽 노광 기술은 일괄 노광 면적은 6"로 유지하면서 <TEX>$0.35{\mu}m$</TEX>에서 <TEX>$1.5{\mu}m$</TEX>의 사이의 패턴을 구현할 수 있는 특별한 능력을 갖고 있다. 이는 기존 광 노광 방식에서 반드시 필요로 하는 결상 광학계를 사용하지 않고 홀로그램 마스크를 사용하기 때문이다. 본 논문에서는 내부전반사 홀로그래픽 노광 기술의 핵심기술인 홀로그램 마스크를 표면 부조 홀로그램 형태로 구현할 수 있는 핵심 인자가 무엇인지를 분석하여 최적화 하는 방법에 대해 논하고, 이를 이용하여 노광한 미세패턴에 대한 결과를 실험적으로 평가하였다. Holographic lithography is one of the potential technologies for next generation lithography which can print large areas (6") as well as very fine patterns (<TEX>$0.35{\mu}m$</TEX>). Usually, photolithography has been developed with two target purposes. One was for LCD applications which require large areas (over 6") and micro pattern (over <TEX>$1.5{\mu}m$</TEX>) exposure. The other was for semiconductor applications which require small areas (1.5") and nano pattern (under <TEX>$0.2{\mu}m$</TEX>) exposure. However, holographic lithography can print fine patterns from <TEX>$0.35{\mu}m$</TEX> to <TEX>$1.5{\mu}m$</TEX> keeping the exposure area inside 6". This is one of the great advantages in order to realize high speed fine pattern photolithography. How? It is because holographic lithography is taking holographic optics instead of projection optics. A hologram mask is the key component of holographic optics, which can perform the same function as projection optics. In this paper, Surface-Relief TIR Hologram Mask technology is introduced, and enables more robust hologram masks than those previously reported that were formed in photopolymer recording materials. We describe the important parameters in the fabrication process and their optimization, and we evaluate the patterns printed from the surface-relief TIR hologram masks.

Fabrication of holographic diffractive optical elements for enhancing light collection from fluorescence-based biochips

An approach to enhancing the light collection from fluorescence emitters bound on the surface of a biochip is presented. It is based on the integration of diffractive optical elements on the underside of the chip that are essentially thick volume holograms written into a layer of photopolymer recording material. The high diffractive efficiency and angular selectivity of these types of diffractive elements make them very effective collectors of the spatially anisotropic light emitted by surface-bound fluorophores. The holographic lithography setup used to fabricate the diffractive elements is described. Results obtained using both a focused laser and light from a fluorescence spot to characterize the performance of the diffractive optical elements are presented.

The Experimental Study of Acrylamide Based Photopolymer Recording Materials for Applications in Optical Holography

AbstractSummary: The photopolymer recording material based on acrylamide monomer has been experimentally studied. After illumination with an interference field, the photopolymerization process is initiated and a diffraction grating is formed in real‐time. The performance of the material depends on its chemical composition and recording parameters. Due to its self‐developing characteristics, the real‐time measurement of hologram formation is used for detection of the recording process. From the measurement, properties of the material can be determined and optimized for different holographic applications.

Optical Response of Photopolymer Materials for Holographic Data Storage Applications

We briefly review the application of photopolymer recording materials in the area of holographic data storage. In particular we discuss the recent development of the Non-local Polymerisation Driven Diffusion model. Applying this model we develop simple first-order analytic expressions describing the spatial frequency response of photopolymer materials. The assumptions made in the derivation of these formulae are described and their ranges of validity are examined. The effects of particular physical parameters of a photopolymer on the material response are discussed.

Polymer holography I – Method and experiment

Processes of radical photopolymerization running during the holographic exposition in photopolymer recording materials are investigated. Special experimental setup, which makes recording and continuous measuring of the forming hologram possible, was built up. An acrylamide-based recording material was prepared and tested. Our experiments verified that addition of bis-acrylamide improves the stability of the hologram due to micronetwork formation.

Analysis and simulations of two-wave mixing in photopolymer holographic recording media

Abstract The process of two-wave mixing in photopolymer recording materials was investigated theoretically. The diffraction grating already forms during exposition and it may influence the original interference field distribution through diffraction of waves on the refractive index modulation. In order to show this, Kogelnik's coupled wave theory was extended to demonstrate the possibility of energy transfer from one recording wave to the other. The energy transfer and the intensity distribution during the recording process were systematically analysed depending on the boundary conditions. As a next step, the first harmonic model of the transmission grating recording, based on a simple material model, was implemented and solved. The ratio of the input intensities was found to be a crucial parameter and thus extensive simulations for various ratios of intensities were carried out. Modelling implies that the interference field and the refractive index grating just coincide for equal intensities. For intensities differing from unity they do not overlap themselves during the recording process. It has also turned out that the diffraction efficiency of the recorded grating drops against the case where the effects of two-wave mixing are not considered. The results of our analysis and simulation help give a better understanding of the physics of the recording process and proper adjustment of recording parameters in such applications as optical holography and holographic memories.

Analysis and simulations of two-wave mixing in photopolymer holographic recording media

The process of two-wave mixing in photopolymer recording materials was investigated theoretically. The diffraction grating already forms during exposition and it may influence the original interference field distribution through diffraction of waves on the refractive index modulation. In order to show this, Kogelnik's coupled wave theory was extended to demonstrate the possibility of energy transfer from one recording wave to the other. The energy transfer and the intensity distribution during the recording process were systematically analysed depending on the boundary conditions. As a next step, the first harmonic model of the transmission grating recording, based on a simple material model, was implemented and solved. The ratio of the input intensities was found to be a crucial parameter and thus extensive simulations for various ratios of intensities were carried out. Modelling implies that the interference field and the refractive index grating just coincide for equal intensities. For intensities differing from unity they do not overlap themselves during the recording process. It has also turned out that the diffraction efficiency of the recorded grating drops against the case where the effects of two-wave mixing are not considered. The results of our analysis and simulation help give a better understanding of the physics of the recording process and proper adjustment of recording parameters in such applications as optical holography and holographic memories.

Holographic and Electronic Speckle‐Pattern Interferometry using a Photopolymer Recording Material

StrainVolume 40, Issue 2 p. 79-81 Holographic and Electronic Speckle-Pattern Interferometry using a Photopolymer Recording Material S. R. Guntaka, S. R. Guntaka Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this authorV. Toal, V. Toal Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this authorS. Martin, S. Martin Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this author S. R. Guntaka, S. R. Guntaka Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this authorV. Toal, V. Toal Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this authorS. Martin, S. Martin Centre for Industrial & Engineering Optics, School of Physics, Dublin Institute of Technology, Kevin St, Dublin 8, IrelandSearch for more papers by this author First published: 17 May 2004 https://doi.org/10.1111/j.1475-1305.2004.00122.xCitations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume40, Issue2May 2004Pages 79-81 RelatedInformation

Distortions in pixel-matched holographic data storage due to lateral dimensional change of photopolymer storage media

Dimensional changes in polymerizable storage materials during exposure are a source of pixel misregistration in digital holographic storage. Lateral shrinkage or expansion of photopolymer recording materials can be deduced from quantitative measurement of the shift and the magnification errors of reconstructed holograms.

Nonlinearities of Photopolymer Holographic Recording Materials

An analysis is presented of the nonlinear effects of holographically recording discrete image points on a phase recording material. The analysis is restricted to thin, two- and three-beam holographic gratings recorded on a material that exhibits a linear phase shift vs exposure. Harmonics, intermodulation noise, and small signal effects are considered. Experimental measurements were carried out for three-beam holographic gratings and diffuse object holograms recorded on photopolymer recording materials. Intermodulation noise is found to be a serious limitation for discrete image point holograms, because this noise cannot be spatially separated from the desired image points. Intermodulation noise can be reduced by increasing the reference-to-object beam irradiance ratio and by reducing the diffraction efficiency. Photopolymer gratings with 50-dB signal-to-intermodulation noise ratio were obtained with diffraction efficiency greater than 1/10% at beam irradiance ratios of 400:1. The image contrast of photopolymer holograms of diffuse objects is compared with the image contrast reported for bleached silver halide emulsions.