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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Optical Society of Korea
Journal Basic Information
Journal DOI :
Optical Society of Korea
Editor in Chief :
Shin, Jung Hoon
Volume & Issues
Volume 13, Issue 4 - Dec 2009
Volume 13, Issue 3 - Sep 2009
Volume 13, Issue 2 - Jun 2009
Volume 13, Issue 1 - Mar 2009
Selecting the target year
Three-dimensional Information and Refractive Index Measurement Using a Dual-wavelength Digital Holographic
Shin, Sang-Hoon ; Yu, Young-Hun ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 173~177
DOI : 10.3807/JOSK.2009.13.2.173
Digital holographic microscopy allows optical path difference measurement. Optical path difference depends on the both refractive index and morphology of sample. We developed a dual-wavelength in-line digital holographic microscope that can measure simultaneously the refractive index and morphology of a sample, providing highly precise three-dimensional information. Here we propose theoretical and experimental methods for dual-wavelength in-line digital holographic microscopy. The measured data were reasonable, although there was data error. By improving the experimental method, we could measure the refractive index more precisely and obtain more accurate three-dimensional information on samples.
Accuracy Assessment for Measuring Surface Figures of Large Aspheric Mirrors
Kim, Young-Soo ; Ahn, Ki-Beom ; Park, Kwi-Jong ; Moon, Il-Kweon ; Yang, Ho-Soon ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 178~183
DOI : 10.3807/JOSK.2009.13.2.178
At the time that the Keck-I 10m telescope was constructed in 1993, the era of Very Large Telescopes (VLTs) was opened. Now thirteen VLTs are in operation, and the largest of the monolithic mirrors is 8.4 m in diameter. Such monolithic mirrors are mostly aspheric and require high accuracies on the surface figures, reaching up to the diffraction limit. At present, next generation telescopes, Giant telescopes, are being developed. One is the GMT (Giant Magellan Telescope) whose size is 25.4 m in diameter. The primary mirror consists of seven segments figuring elliptical shapes on the surface. The surrounding six segments are off-axis and the edges are steep, as the fast focal ratio is adopted. It means that testing of the mirrors is a challenging task. In this paper, testing methods for the GMT primary mirror are reviewed, and accuracy of measuring devices is assessed. Results and discussions follow.
Analytic Design Procedure of Three-mirror Telescope Corrected for Spherical Aberration, Coma, Astigmatism, and Petzval Field Curvature
Lee, Jong-Ung ; Yu, Seung-Moon ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 184~192
DOI : 10.3807/JOSK.2009.13.2.184
There are total eight degrees of freedom in designing a three-mirror system. If we correct four kinds of third order aberrations and the system should have the specified effective focal length, the remaining three degrees of freedom can be used for selecting a suitable configuration for a specific application. We suggest an analytic design procedure for a three-mirror telescope system which has a suitably sized secondary mirror and proper separations between mirrors, and is corrected for four kinds of third order aberrations, spherical aberration, coma, astigmatism, and field curvature. Two design examples are shown. One has a compact configuration with off-axial field, the other has relatively long configuration with annular ring field.
Optomechanical Design of a Compact Imaging Spectrometer for a Microsatellite STSAT3
Lee, Jun-Ho ; Lee, Chi-Weon ; Kim, Yong-Min ; Kim, Jae-Wook ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 193~200
DOI : 10.3807/JOSK.2009.13.2.193
A compact imaging spectrometer (COMIS) is currently under development for use in the STSAT3 microsatellite. COMIS images the Earth's surface and atmosphere with ground sampling distances of
spectral bands (
) for the nadir looking at an altitude of 700 km. COMIS has an imaging telescope and an imaging spectrometer box into which three electronics PCBs are embedded. These are designed into a single assembly with dimensions of 35(L)
and a mass of 4.3 kg. Optomechanical design efforts are focused on manufacturing ease, alignment, assembly, testing and improved robustness in space environments. Finite element analysis demonstrates that COMIS will survive in launch and space environments and perform the system modulation transfer function (MTF) in excess of 0.29 at the Nyquist frequency of the CCD detector (38.5 lines-per-mm).
Athermal Elastomeric Lens Mount for Space Optics
Kihm, Hag-Yong ; Yang, Ho-Soon ; Moon, Il-Kweon ; Lee, Yun-Woo ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 201~205
DOI : 10.3807/JOSK.2009.13.2.201
We investigated the optimum adhesive thickness for athermalizing an elastomeric lens mount in our space optics application. Theoretical results were compared with finite element solutions using two different models; discrete circular pads and discrete circular pads with columns filling the insertion holes reflecting the reality. A noticeable difference between their optimal thicknesses was observed, and physical interpretation revealed the uncertainty of prevailing athermal equations. A pilot sample was made to check our results and thermo-optical stress was assessed using an interferometer after isothermal load. This study presented insight into preliminary design guidance in elastomeric lens mounting.
Compact Zoom Lens Design for a 5x Mobile Camera Using Prism
Park, Sung-Chan ; Lee, Sang-Hun ; Kim, Jong-Gyu ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 206~212
DOI : 10.3807/JOSK.2009.13.2.206
This study presents the compact zoom lens with a zoom ratio of 5x for a mobile camera by using a prism. The lens modules and aberrations are applied to the initial design for a four-group inner-focus zoom system. An initial design with a focal length range of 4.4 to 22.0 mm is derived by assigning the first-order quantities and third-order aberrations to each module along with the constraints required for optimum solutions. We separately designed a real lens for each group and then combined them to establish an actual zoom system. The combination of the separately designed groups results in a system that satisfies the basic properties of the zoom system consisting of the original lens modules. In order to have a slim system, we directly inserted the right-angle prism in front of the first group. This configuration resulted in a more compact zoom system with a depth of 8 mm. The finally designed zoom lens has an f-number of 3.5 to 4.5 and is expected to fulfill the requirements for a slim mobile zoom camera having high zoom ratio of 5x.
Transcription Characteristics of Mold Surface Topography in the Molding of Aspherical Glass Lenses
Cha, Du-Hwan ; Hwang, Yeon ; Kim, Jeong-Ho ; Kim, Hye-Jeong ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 213~217
DOI : 10.3807/JOSK.2009.13.2.213
The transcription characteristics of the mold surface in the molding of aspherical glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. For the form topography, the molded lens showed a transcription ratio of 93.4% against the mold, which is obtained by comparing the form error (PV) values of the mold and the molded lens. The transcription characteristics of the roughness topography were ascertained by bearing ratio analysis.
Optical and Structural Properties of Bilayer Circular Filter Prepared by Glancing Angle Deposition
Park, Yong-Jun ; Sobahan, KM Abdus ; Kim, Jin-Joo ; HwangBo, Chang-Kwon ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 218~222
DOI : 10.3807/JOSK.2009.13.2.218
In this paper, we report the optical and structural properties of a bilayer circular filter fabricated by a glancing angle deposition technique. The bilayer circular filter is realized by a two-layer
helical film with layers of opposite structural handedness. It is found that the bilayer circular filter reflects both right and left circularly polarized light with wavelength lying in the Bragg regime. The microstructure of the bilayer circular filter is also investigated using a scanning electron microscope.
A Magneto-optical Trap Below a Dielectric Coated Mirror Surface
Yu, Hoon ; Lee, Lim ; Lee, Kyung-Hyun ; Kim, Jung-Bog ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 223~226
DOI : 10.3807/JOSK.2009.13.2.223
A Magneto-Optical Trap (MOT) for
atoms near the surface of a dielectric coated mirror at the top of a small
cell has been observed. Two beams of
were used for optical cooling and an anti-Helmholtz magnetic field with a spatial gradient of 9.1 G/cm was used for magnetic trapping. The thickness of the mirror coated on a cover glass was less than
. The mirror covered the top of a cell and the atom-chip was located outside the vacuum in order to exploit the long life time of the mirror and easy operation of the chip. The trapping position was found 5 mm beneath the mirror surface. The number of trapped atoms was roughly
atoms and the temperature was approximately a few tens mK. In this paper, we describe the construction of the mirror-MOT in detail.
Theoretical Investigation of First-order and Second-order Polarization-mode Dispersion Tolerance on Various Modulation Formats in 40 Gb/s Transmission Systems with FEC Coding
Jang, Ho-Deok ; Kim, Kyoung-Soo ; Lee, Jae-Hoon ; Jeong, Ji-Chai ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 227~233
DOI : 10.3807/JOSK.2009.13.2.227
We investigated the polarization-mode dispersion (PMD) tolerance for 40Gb/s non-return to zero (NRZ), duobinary NRZ, return to zero (RZ), carrier-suppressed RZ (CS-RZ), and duobinary-carrier-suppressed RZ (DCS-RZ) modulation formats with a forward error correction (FEC) coding. The power penalty has been calculated as a measure of the system performance due to PMD. After comparison of the PMD tolerance of various modulation formats, our results suggest that RZ signals have the best tolerance against the effect of first-order PMD only. The duobinary NRZ modulation format is most resilient to PMD when both first- and second-order PMD are considered. However, the duobinary NRZ modulation format is the most sensitive to the incident angle of the input signal to a fiber axis in the presence of first- and second-order PMD, leading to incident angle-dependent power penalty. The coding gain by FEC can cope with the power penalties induced by first- and second-order PMD up to a DGD value of 16ps.
Transmission and Sensing Characteristics of the Biconically Tapered Cladded Multimode Fibers
Kim, Kwang-Taek ; Hong, Ki-Bum ; Park, Jae-Hee ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 234~239
DOI : 10.3807/JOSK.2009.13.2.234
This paper presents a theoretical and experimental investigation of the transmission and sensing characteristics of the biconically tapered cladded multimode fibers. The beam propagation method was used to examine the transmission characteristics with various structural parameters. The results show that the transmission of the biconically tapered cladded multimode fibers is sensitive to the mode of the input optical beam and the refractive index of the external medium. A refractive index sensor for the external medium was proposed based on the theoretical analysis, and its feasibility was demonstrated experimentally.
Er-doped Superfluorescent Fiber Source with Thermally Stable Mean Wavelength
Park, Hee-Gap ; Yun, Seung-Chul ; Jin, Young-Jun ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 240~244
DOI : 10.3807/JOSK.2009.13.2.240
An Er-doped superfluorescent fiber source is designed and constructed with the double-pass forward configuration, which aims at high stability of its mean wavelength against temperature variation. As a result, thermal stability of mean wavelength better than 1 ppm is obtained against the temperature variation of
around the optimum operating temperature. The optimum operating temperature can be tuned with the Er-doped fiber length and the pump power.
Measurement of a Mirror Surface Topography Using 2-frame Phase-shifting Digital Interferometry
Jeon, Seok-Hee ; Gil, Sang-Keun ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 245~250
DOI : 10.3807/JOSK.2009.13.2.245
We propose a digital holographic interference analysis method based on a 2-frame phase-shifting technique for measuring an optical mirror surface. The technique using 2-frame phase-shifting digital interferometry is more efficient than multi-frame phase-shifting techniques because the 2-frame method has the advantage of a reduced number of interferograms, and then takes less time to acquire the wanted topography information from interferograms. In this measurement system, 2-frame phase-shifting digital interferograms are acquired by moving the reference flat mirror surface, which is attached to a piezoelectric transducer, with phase step of 0 or
/2 in the reference beam path. The measurements are recorded on a CCD detector. The optical interferometry is designed on the basis of polarization characteristics of a polarizing beam splitter. Therefore the noise from outside turbulence can be decreased. The proposed 2-frame algorithm uses the relative phase difference of the neighbor pixels. The experiment has been carried out on an optical mirror which flatness is less than
/4. The measurement of the optical mirror surface topography using 2-frame phase-shifting interferometry shows that the peak-to-peak value is calculated to be about
, the root-mean-square value is about
. Thus, the proposed method is expected to be used in nondestructive testing of optical components.
A High-speed Digital Laser Grating Projection System for the Measurement of 3-dimensional Shapes
Park, Yoon-Chang ; Park, Chul-Geun ; Ahn, Seong-Joon ; Kang, Moon-Ho ; Ahn, Seung-Joon ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 251~255
DOI : 10.3807/JOSK.2009.13.2.251
In the non-contact 3-dimensional (3D) shape measurements, the fringe pattern projection method based on the phase-shifting technique has been considered very effective for its high speed and accuracy. The digital fringe projector in particular has great flexibility in generating fringe patterns since the patterns can be controlled easily by the computer program. In this work, we have developed a high-speed digital laser grating projection system using a laser diode and a polygon mirror, and evaluated its performance. It has been demonstrated that all the optical measurements required to find out the profile of a 3D object could be carried out within 31 ms, which confirmed the validity of our 3D measurement system. The result implies the more important fact that the speed in 3D measurement can be enhanced remarkably since, in our novel system, there is no device like a LCD or DMD whose response time limits the measurement speed.
Correlation Between the Optical Performance of the Reflective Polarizer and the Structure of LCD Backlight
Yu, Mi-Yeon ; Lee, Byung-Woo ; Lee, Jeong-Ho ; Ko, Jae-Hyeon ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 256~260
DOI : 10.3807/JOSK.2009.13.2.256
The optical performance of the reflective polarizer was investigated over three kinds of direct-lit backlights and/or different configurations of the optical sheets. The optical gain factor achieved by using the reflective polarizer increased as the diffuse nature of the optical sheet was enhanced, because of the more efficient polarization conversion. In addition, the gain factor decreased substantially in flat-lamp backlights compared to tubular-lamp backlights, which was ascribed to the high loss factor during the polarization recycling process due to the complex structure and large area of flat lamps. All these results suggested that reducing the loss factor of the backlight is very important for efficient polarization conversion and thus high optical gain of the reflective polarizer.
Angular Dispersion-type Nonscanning Fabry-Perot Interferometer Applied to Ethanol-water Mixture
Ko, Jae-Hyeon ; Kojima, Seiji ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 261~266
DOI : 10.3807/JOSK.2009.13.2.261
The angular dispersion-type non-scanning Fabry-Perot was applied to an ethanol-water mixture in order to investigate its acoustic properties such as the sound velocity and the absorption coefficient. The scattered light from the mixture was analyzed by using the charge-coupled-device area detector, which made the measurement time much shorter than that obtained by using the conventional scanning tandem multi-pass Fabry-Perot interferometer. The sound velocity showed a deviation from ultrasonic sound velocities at low temperatures accompanied by the increase in the absorption coefficient, indicating acoustic dispersion due to the coupling between the acoustic waves and some relaxation process. Based on a simplified viscoelastic theory, the temperature dependence of the relaxation time was obtained. The addition of water molecules to ethanol reduced the relaxation time, consistent with dielectric measurements. The present study showed that the angular dispersion-type Fabry-Perot interferometer combined with an area detector could be a very powerful tool in the real-time monitoring of the acoustic properties of condensed matter.
A Comparison of Wavelength Dependence for Laser-assisted Lipolysis Effect Using Monte Carlo Simulation
Youn, Jong-In ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 267~271
DOI : 10.3807/JOSK.2009.13.2.267
The aim of this study is to evaluate wavelength dependence for laser-assisted lipolysis using a mathematical simulation. In this study, a Monte Carlo simulation was performed to simulate light transport in fat and dermal tissue with 3 different laser wavelengths (
, 1320 nm, and 1444 nm) that are currently used in clinic settings for laser-assisted lipolysis. The relative rates of heat generation versus penetration depth showed that the greatest amount of heat generation was seen in the tissues at
. This Monte Carlo simulation may help lend insight into the thermal events occurring inside the fat and dermal tissue during laser-assisted lipolysis.
Finite-difference Time-domain Study on Birefringence Changes of the Axon During Neural Activation
Lee, Jong-Hwan ; Kim, Sung-June ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 272~278
DOI : 10.3807/JOSK.2009.13.2.272
Recently, there has been a growing interest in optical imaging of neural activity because the optical neuroimaging has considerable advantages over conventional imaging. Birefringence of the axon has been reported to change during neural activation, but the neurophysiological origin of the change is still unresolved. This study hypothesizes that the birefringence signal is at least partially attributed to the transient cellular volume change associated with nerve excitation. To examine this hypothesis, we investigated how the intensity of cross-polarized light transmitting through the axon would change as the size of the axon changes. For this purpose, a two-dimensional finite-difference time-domain program was developed with the improvement of the total-field/scattered-field method which reduces numerical noise. The results support our hypothesis in that the computed cross-polarized signals exhibit some agreement with previously-reported birefringence signals.
Glucose Prediction in the Interstitial Fluid Based on Infrared Absorption Spectroscopy Using Multi-component Analysis
Kim, Hye-Jeong ; Noh, In-Sup ; Yoon, Gil-Won ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 279~285
DOI : 10.3807/JOSK.2009.13.2.279
Prediction of glucose concentration in the interstitial fluid (ISF) based on mid-infrared absorption spectroscopy was examined at the glucose fundamental absorption band of 1000 - 1500/cm (10 - 6.67 um) using multi-component analysis. Simulated ISF samples were prepared by including four major ISF components. Sodium lactate had absorption spectra that interfere with those of glucose. The rest NaCl, KCl and
did not have any signatures. A preliminary experiment based on Design of Experiment, an optimization method, proved that sodium lactate influenced the prediction accuracy of glucose. For the main experiment, 54 samples were prepared whose glucose and sodium lactate concentration varied independently. A partial least squares regression (PLSR) analysis was used to build calibration models. The prediction accuracy was dependent on spectrum preprocessing methods, and Mean Centering produced the best results. Depending on calibration sample sets whose sodium lactate had different concentration levels, the standard error prediction (SEP) of glucose ranged
Optimal Shape Design of Dielectric Micro Lens Using FDTD and Topology Optimization
Chung, Young-Seek ; Lee, Byung-Je ; Kim, Sung-Chul ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 286~293
DOI : 10.3807/JOSK.2009.13.2.286
In this paper, we present an optimal shape design method for a dielectric microlens which is used to focus an incoming infrared plane wave in wideband, by exploiting the finite difference time domain (FDTD) technique and the topology optimization technique. Topology optimization is a scheme to search an optimal shape by adjusting the material properties, which are design variables, within the design space. And by introducing the adjoint variable method, we can effectively calculate a derivative of the objective function with respect to the design variable. To verify the proposed method, a shape design problem of a dielectric microlens is tested when illuminated by a transverse electric (TE)-polarized infrared plane wave. In this problem, the design variable is the dielectric constant within the design space of a dielectric microlens. The design objective is to maximally focus the incoming magnetic field at a specific point in wideband.
Polymeric Waveguides with Bragg Gratings in the Middle of the Core Layer
Jeong, In-Soek ; Park, Hae-Ryeong ; Lee, Sang-Won ; Lee, Myung-Hyun ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 294~298
DOI : 10.3807/JOSK.2009.13.2.294
In this paper we proposed a new Bragg grating waveguide in order to improve reflectivity and to achieve compactness. Bragg gratings with various thicknesses were engraved in the middle of the core layer with a length of 3 mm. For the sake of cost-effectiveness, the
order Bragg grating waveguides were fabricated via conventional photolithography. The maximum reflectivities for the fixed width waveguide of
with the 0.1 and
-thick Bragg gratings were, -13.14 and -6.25 dB, respectively, and the Bragg wavelengths were 1562.28, 1564.10 nm, respectively. A slight increase in the Bragg grating thickness can result in a remarkable reduction in the length of the Bragg grating waveguide with a fixed reflectivity.
Characteristics of Solc Filters in X
Nonlinear Photonic Crystals[Author's correction]
Kee, Chul-Sik ; Lee, Jong-Min ; Lee, Yeung-Lak ;
Journal of the Optical Society of Korea, volume 13, issue 2, 2009, Pages 299~299
DOI : 10.3807/JOSK.2009.13.2.299