• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.747-748
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• 2008

• Current Optics and Photonics
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• v.4 no.6
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• pp.477-482
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• 2020

Recently, one of the authors has been reported an optically tunable fiber Bragg grating (FBG) with a photomechanical polymer. It was based on a typical FBG with a downsized diameter of 60 ㎛, coated with azobenzene-containing polymer material. Azobenzene is a well-known reversibly photomechanical stretchable material under ultraviolet (UV) light. The small part of the functional-coating region on the FBG absorbed UV light, which pulled the UV-exposed part of the grating. It was selectable as tunable FBG or tunable chirped FBG, by adjusting the position of UV exposure on the grating. As proof of concept for the tunable FBG device, the characteristics just including UV-induced center-wavelength shift and spectral-width changes of the device were reported. In this paper, we report for the first time that the microactuator makes it possible to control the spectral shape of the FBG reflection, according to the specifications (shape and intensity) of the UV beam that reaches the FBG coated with the azobenzene polymer. In addition, we provide the group-delay profiles for the chirped FBG, so that the sign of its dispersion (normal or anomalous) can be tailored by simply selecting the moving direction of the UV light's displacement in the experiment.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.2
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• pp.69-78
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• 2006

Proofing is one of the inspection operations of printing and can be considered a process control step. The three main kinds of proofs are press proofs, photomechanical proofs, and digital proofs. Photomechanical and digital proofs are also generally refered to as "off-press" proofs. Off-press color proofs are more economical than press proofs. Digital proofs offer fast production time along with a much lower cost per page. Hard-copy digital proofs can be output using thermal transfer printers, ink jet printers, and color laser copiers, as well as dye sublimation and electrophotographic technology. Ink jet method is commonly using because of the reasonal price. But ink jet system is difficult to reproduce an exact color proof. This research was carried out for the purpose of optimization of ink jet color proofing, using two kinds of ink jet printers with 6 colors (C, M, Y, K, mC, mM) and 4 colors (C, M, Y, K) system.

• Journal of Photoscience
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• v.2 no.1
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• pp.31-35
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• 1995

Light signals in the form of intensity gradient, propagation direction, and wavelength elicit diverse mechanical responses ("photomechanical responese") in most organisms. The single cell ciliates, Stentor coeruleus and Blepharisma japonicum, are particularly sensitive to the light of visible wavelengths. In this paper, the way in which the seemingly sophisticated light signal transduction is triggered by the photosensory apparatus will be described in terms of the photoreceptor structure and photochemical function.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.609-610
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• 2011

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.11
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• pp.1483-1491
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• 2001

Enhancement of pulsed-laser ablation by an artificially deposited liquid film is presented. Measurements of ablation rate, ablation threshold, and surface topography arc performed. Correlation between material ablation and photoacoustic effect is examined by the optical beam deflection method. The dependence of ablation rate on liquid-film thickness and chemical composition is also examined. The results indicate that photomechanical effect in the phase explosion of liquid is responsible for the enhanced ablation. The low critical temperature of liquid induces explosive vaporization with localized photoacoustic excitation in the superheat limit and increases the ablation efficiency. Experiments were carried out utilizing a Q-swiched Nd:YAG laser at near-threshold laser fluences with negligible plasma effect (up to ∼100 MW/cm$^2$).

• Elastomers and Composites
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• v.47 no.4
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• pp.282-291
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• 2012

Control of shape/volume, mechanical, optical, electrical, and chemical switching of materials by external stimuli such as light, temperature, pH, electric field, and pressure has attracted great attention. Among these materials, photo-responsive materials containing photochromic compounds such as azobenzene, spiropyran, and cinnamic acid groups have been the subject of intense interest in recent years. In this review, we describe the recent progress in the area of azobenzene containing polymer materials that can convert light energy into mechanical energy directly. Especially we focus our attention on light-driven actuators such as artificial muscle, motor, and valve. We summarize the photomechanical effects in liquid crystal elastomer, amorphous polymer, monolayer, and supramolecules containing azobenzene, respectively.