• Current Optics and Photonics
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• v.1 no.6
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• pp.618-625
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• 2017

In the present research, a new bending system using a segmented vacuum chuck for Stressed Mirror Polishing (SMP) is developed. SMP is a special fabrication method for thin aspheric mirrors, where simple flat or spherical fabrication is applied while a mirror blank is deflected. Since a mirror blank is usually glued to a bending fixture in the conventional SMP process, there are drawbacks such as long curing time, inconvenience of mirror replacement, risk of mirror breakage, and stress concentration near the glued area. To resolve the drawbacks, a new bending system is designed to effectively hold a mirror blank by vacuum. For the developed bending system, the optimal bending load to achieve the designated mirror deflection is found by finite element analysis and an optimization algorithm. With the measurement results of the deflected mirror surfaces with the optimal bending loads, the feasibility of the developed bending system is investigated. As a result, it is shown that the bending system is appropriate for the SMP process.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.591-596
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• 2006

Lead zirconate titanate(PZT) thin films have been attracting worldwide interests in exploring their potential properties [1-3] or the origins [4-6] of their excellent dielectic, ferroelectric and piezoelectric properties near the morphotropic phase boundary (MPB). PZT thin films are expected to apply to the memory devices, micro electro mechanical systems (MEMS), and display because of their superior ferroelectric, pyroelectric, piezoelectric and electron emission properties. In this study, high- performance piezoelectric PZT thin films for actuated mirror array and optical scanner were developed by controlling the several factors, such as molecular-designed precursor, seeding layer and the residual stress in films, by a chemical solution deposition (CSD).

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.263-266
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• 2007

We report a nickel optical MEMS switch, being able to rotate through a large angle and to accommodate multiple channels. The proposed optical switch consists of a thin nickel mirror and two torsion springs supporting the mirror. The torsion springs are designed using a finite element method (FEM) such that plastic deformation of the thin nickel is avoided during the large torsion actuation. For switching speed improvement, transient vibration of the released mirror is suppressed by optimizing the mirror design and a fast switching response of $200\;{\mu}s\;(pull-down)/300\;{\mu}s\;(pull-up)$ is demonstrated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.244-247
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• 1995

Physical, electrical and optical properties of Aluminum(Al) thin films were investigated in order to establish the optimum sputtering parameters in mirror reflection films. Al. thin films deposited on corning glass substrate by DC magnetron sputtering were grown as a variation of the input power, operation pressure and deposition time. The properties of the Al thin films have been discussed by deposition rate, SEM, XRD, sheet resistivity, resistivity and reflectance. Al thin films were obtained at the deposition conditions as follows: operating pressure, 3 mtorr; DC input power desnsitiy, 3W/$\textrm{cm}^2$.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.80-84
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• 2012

A high reflectance mirror, which has very low absorption and scattering loss, was coated onto a crystalline substrate by ion beam sputtering and then annealed at $450^{\circ}C$. We carefully selected the mirror coating material, and designed the high reflectance mirror, in order to avoid UV degradation which comes from the He-Ne plasma. We measured the surface roughness of the Zerodur substrate using phase shift interferometry and atomic force microscopy, and compared it with the TIS scattering of the mirror. The cavity ring-down method was used to measure the absorption of the mirror, and the thin film structure was correlated to its results. We also compared the optical properties of coated mirrors before and after annealing.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3292-3294
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• 1999

In this paper, electrostatic scanner mirror for optical pick-up head is designed and fabricated. The mirror size is $20{\mu}m{\times}2400{\mu}m{\times}2400{\mu}m$ and torsional beam size is $10{\mu}m{\times}20{\mu}m{\times}500{\mu}m$. Static deflection angle is calculated ${\pm}0.4$ degrees when the maximum driving voltage is 20 V. Silicon mirror was fabricated using KOH etching and deep RIE. For passivation of the patterned mirror from KOH solution, parylene thin film was used and its usefulness has been verified. Driving electrode was fabricated using UV LIGA process. Mirror and electrode were bonded.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.121-123
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• 2007

As a reflector of reference arm in OCT systems, a coated fiber reflector has mostly used. Instead, this paper has realized the swaept source optical coherence tomography system using a loop mirror within a reference arm. Through the experiments for a tilted thin glass plate, we found that the loop mirror is better than the coated fiber typed mirror for obtaining the clear image.

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.187-188
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• 2007

Four kinds of mirror substrates with same surface roughness were fabricated. On those substrates, a dielectric multi-layer coating with high reflectivity was deposited by ion beam sputtering technique. Most of the fused silica mirrors showed lower scattering than the ZERODUR mirrors one, which deposited on substrates similar in surface roughness. The ZERODUR mirrors scattering strongly depend on the micro-structure of $Ta_2O_5/SiO_2$ thin films wear deposited on ZERODUR substrates.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.296-299
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• 2013

A low density lipoprotein (LDL) cholesterol testing device, structured with serial reflected face-to-face mirror (SRM) allowing spectrophotometry measurements, is presented. The spectrophotometry has been employed to measure the amount of light that a sample absorbs, but it generally should have had path length longer than 10 mm to secure enough sensitivity. Such requirement of path length has often been problematic in implementing a thin type of lab on a disc (LOD). We developed the SRM system which was implemented in a detection chamber with 1.4mm thickness, providing path length longer than 10mm, and thus straightforwardly being applicable to LOD as thin as a compact disc. The experimental results show that the SRM system gives not only a much thinner design compared to the conventional spectrophotometry-based LOD but also a comparable performance to already commercialized spectrometers.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.200-201
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• 2004