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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Optical Society of Korea
Journal Basic Information
Journal DOI :
Optical Society of Korea
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Volume & Issues
Volume 16, Issue 4 - Dec 2012
Volume 16, Issue 3 - Sep 2012
Volume 16, Issue 2 - Jun 2012
Volume 16, Issue 1 - Mar 2012
Selecting the target year
A 150-Mb/s CMOS Monolithic Optical Receiver for Plastic Optical Fiber Link
Park, Kang-Yeob ; Oh, Won-Seok ; Ham, Kyung-Sun ; Choi, Woo-Young ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 1~5
DOI : 10.3807/JOSK.2012.16.1.001
This paper describes a 150-Mb/s monolithic optical receiver for plastic optical fiber link using a standard CMOS technology. The receiver integrates a photodiode using an N-well/P-substrate junction, a pre amplifier, a post amplifier, and an output driver. The size, PN-junction type, and the number of metal fingers of the photodiode are optimized to meet the link requirements. The N-well/P-substrate photodiode has a 200-
optical window, 0.1-A/W responsivity, 7.6-pF junction capacitance and 113-MHz bandwidth. The monolithic receiver can successfully convert 150-Mb/s optical signal into digital data through up to 30-m plastic optical fiber link with -10.4 dBm of optical sensitivity. The receiver occupies 0.56-
area including electrostatic discharge protection diodes and bonding pads. To reduce unnecessary power consumption when the light is not over threshold or not modulating, a simple light detector and a signal detector are introduced. In active mode, the receiver core consumes 5.8-mA DC currents at 150-Mb/s data rate from a single 3.3 V supply, while consumes only
in the sleep mode.
Optical Modeling for Polarization-dependent Optical Power Dissipation of Thin-film Organic Solar Cells at Oblique Incidence
Kim, Jungho ; Jung, Sungyeop ; Jeong, Inkyung ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 6~12
DOI : 10.3807/JOSK.2012.16.1.006
We present the optical models and calculation results of thin-film organic solar cells (OSCs) at oblique incidence of light, using the transfer matrix method. The simple expression for the optical power dissipation is derived at oblique incidence for s- and p-polarized light. The spatial distribution of the electric field intensity, the optical power density, and the optical power dissipation are calculated in both s- and p-polarized light with respect to the incidence angle. We identify how the light absorption efficiency for p-polarized light becomes relatively larger than that for s-polarized light as the incidence angle increases.
Ultrahigh Speed Reconfigurable Logic Operations Based on Single Semiconductor Optical Amplifier
Kaur, Sanmukh ; Kaler, Rajinder-Singh ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 13~16
DOI : 10.3807/JOSK.2012.16.1.013
We demonstrate an optical gate architecture using a single SOA to perform AND, OR and NOT logic functions. Simple reconfigurable all-optical logic operations are implemented using RZ modulated signals at 40 Gb/s. Contrast ratio and extinction ratio values have been analysed for the different types of logic gates. Maximum extinction ratio and contrast ratio achieved are 19dB and 17.2 dB respectively. Simple structure and potential for integration makes this architecture an interesting approach in photonic computing and optical signal processing.
Photopolymer-based Surface-normal Input/Output Volume Holographic Grating Coupler for 1550-nm Optical Wavelength
Lee, Kwon-Yeon ; Jeung, Sang-Huek ; Cho, Byung-Mo ; Kim, Nam ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 17~21
DOI : 10.3807/JOSK.2012.16.1.017
A surface-normal input/output volume holographic grating coupler (VHGC) operating at 1550nm wavelength region by using a
-thick DuPont photopolymer film is designed and fabricated. The angular and wavelength responses of the input/output VHGC are investigated in order to validate applicability of this device in integrated optics and optical communications. The effect of incident-beam position on the output reflectance to determine optimum condition for input coupling is also presented. The fabricated input/output VHGC exhibited an angular selectivity of
, a wavelength selectivity of ~0.8 nm, and an output peak reflectance of 34.13%.
Variable-focus Liquid Lens Based on a Laterally-integrated Thermopneumatic Actuator
Lee, June Kyoo ; Park, Kyung-Woo ; Lim, Geunbae ; Kim, Hak-Rin ; Kong, Seong Ho ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 22~28
DOI : 10.3807/JOSK.2012.16.1.022
We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.
Elemental Image Generation Method with the Correction of Mismatch Error by Sub-pixel Sampling between Lens and Pixel in Integral Imaging
Kim, Jonghyun ; Jung, Jae-Hyun ; Hong, Jisoo ; Yeom, Jiwoon ; Lee, Byoungho ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 29~35
DOI : 10.3807/JOSK.2012.16.1.029
We propose a subpixel scale elemental image generation method to correct the errors created by finite display pixel size in integral imaging. In this paper, two errors are mainly discussed: pickup-and-display mismatch error and mismatch error between pixel pitch and lens pitch. The proposed method considers the relative positions between lenses and pixels in subpixel scale. Our proposed pickup method calculates the position parameters, generates an elemental image with pixels completely inside the lens, and generates an elemental image with border pixels using a weighted sum method. Appropriate experiments are presented to verify the validity of the proposed method.
A Study of the Optical Properties of Cosmetics Measured by Polarized Light Goniophotometry
Choi, Sun Kyung ; Yang, Young Jun ; Kim, Kyung Nam ; Choi, Jaewook ; Choi, Yeong Jin ; Han, Sang Hoon ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 36~41
DOI : 10.3807/JOSK.2012.16.1.036
Polymethylmethacrylate powders are commonly used to improve the spreadability and blurring effects of powder foundation cosmetics. In this study, the opacity and haze effect of four types of polymethylmethacrylate powders and their 10wt% powder foundation formulation was evaluated. The distorted random hemispherical particulates with both concave and convex portions showed the highest haze and opacity value as a single powder substance. And as a formulated phase, the powder foundation formulation containing particulates with fine pores provided the highest haze and opacity value. We also examined the quantity of reflected light over the angular range
by polarized light goniophotometry. The total reflected light intensity, surface-reflected light, and internally reflected light were characterized. These studies demonstrated that hemispherical PMMA powders produce natural brilliance by creating high internally reflected light which is similar to the total reflection profile of artificial skin.
In Situ Fluorescence Optical Detection Using a Digital Micromirror Device (DMD) for 3D Cell-based Assays
Choi, Jong-Ryul ; Kim, Kyujung ; Kim, Donghyun ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 42~46
DOI : 10.3807/JOSK.2012.16.1.042
We have developed a fluorescence optical detection system using a digital micromirror device (DMD) for monitoring 3D cell culture matrices in situ. Full 3D imaging with fast scanning speed was implemented by the combined action of a DMD and a motorized stage. Imaging results with fluorescent microbeads measure the minimum axial resolution of the system as
, while full 1-mm scanning through 3D alginate-based matrix was demonstrated. For cell imaging, improved images were obtained by removing background fluorescence although the scanning distance was reduced because of low intracellular fluorescence efficiency. The system is expected to be useful to study various dynamics and behaviors of 3-dimensionally cultured cells in microfluidic systems.
Electro-optic Electric Field Sensor Utilizing Ti:LiNbO
Symmetric Mach-Zehnder Interferometers
Jung, Hong-Sik ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 47~52
DOI : 10.3807/JOSK.2012.16.1.047
The use of a
symmetric Mach-Zehnder interferometric intensity modulator with a push-pull lumped electrode and a plate-type probe antenna to measure an electric field strength is described. The modulator has a small device size of
and operates at a wavelength of
. The output characteristic of the interferometer shows the modulation depth of 100% and 75%, and
voltage of 6.6 V, and 6.6 V at the 200 Hz and 1 KHz, respectively. The minimum detectable electric field is ~1.84 V/m, ~3.28 V/m, and ~11.6 V/m, corresponding to a dynamic range of about ~22 dB, ~17 dB, and ~6 dB at frequencies of 500 KHz, 1 MHz and 5 MHz, respectively.
Development and Characterization of a 400-W Slab-type Nd:YAG Gain Module
Cha, Yong-Ho ; Lee, Sungman ; Lim, Gwon ; Baik, Sung-Hoon ; Kwon, Sung-Ok ; Cha, Byung-Heon ; Lee, Jung-Hwan ; Kang, Eung-Cheol ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 53~56
DOI : 10.3807/JOSK.2012.16.1.053
We have developed a slab-type Nd:YAG gain module based on the techniques of conduction cooling and end pumping. The Nd:YAG slab is end-capped on both ends by undoped pure YAG and is pumped through the end-caps by stacked arrays of laser diode bars. The slab's surfaces of total internal reflection are in contact on both sides with microchannel cooling blocks which are cooled by water circulation. The power oscillator based on the gain module generates more than 400 W at 1-kW pumping with a slope efficiency of 55%. The small-signal gain of the gain module is 10 in a single zig-zag pass, and the amplified beam shows a near diffraction-limited beam quality.
Partial Least Squares-discriminant Analysis for the Prediction of Hemodynamic Changes Using Near Infrared Spectroscopy
Seo, Youngwook ; Lee, Seungduk ; Koh, Dalkwon ; Kim, Beop-Min ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 57~62
DOI : 10.3807/JOSK.2012.16.1.057
Using continuous wave near-infrared spectroscopy, we measured time-resolved concentration changes of oxy-hemoglobin and deoxy-hemoglobin from the primary motor cortex following finger tapping tasks. These data were processed using partial least squares-discriminant analysis (PLS-DA) to develop a prediction model for a brain-computer interface. The tasks were composed of a series of finger tapping for 15 sec and relaxation for 45 sec. The location of the motor cortex was confirmed by the anti-phasic behavior of the oxy- and deoxy-hemoglobin changes. The results were compared with those obtained using the hidden Markov model (HMM) which has been known to produce the best prediction model. Our data imply that PLS-DA makes better judgments in determining the onset of the events than HMM.
Dual Band Optical Window (DBW) for Use on an EO/IR Airborne Camera
Park, Kwang-Woo ; Park, Sang-Yeong ; Kim, Young-Soo ; Kim, Ki-Ho ; Choi, Young-Soo ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 63~69
DOI : 10.3807/JOSK.2012.16.1.063
This paper presents a method to derive the theoretical requirements for the development of a 400 mm optical window that transmits dual-band wavelengths and had a stable structure. We also present design and fabrication results. Among the required specifications, the surface figure error was defined by the transmitted wavefront deformation (TWD),
/15 rms at 632.8 nm. This value was derived by estimating the predicted performances with respect to five independent items that could cause system performance degradation and then calculating the required wavefront error (WFE) to satisfy the performance goals. We measured the image resolution at each performance level to trace and verify the requirements. The article also describes a design optimization process that could minimize the weight and volume of the optical window attached to the payload securing the FOV of the camera. In addition, we accurately measured the deformation that occurred in the series of fabrication steps including processing, coating, assembly, bonding and bolting, and investigated the effects by comparing them to the results of a simulation performed in advance to derive the predicted performance.
Optimal Design of Dielectric-Filled Plasmonic Slot Waveguide with Genetic Algorithm
Kim, Daekeun ; Jung, Jaehoon ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 70~75
DOI : 10.3807/JOSK.2012.16.1.070
An optimization methodology for designing a dielectric-filled plasmonic slot waveguide is presented. The genetic algorithm combined with a rigorous analysis based on the finite element method is used to optimize a nano-scaled plasmonic slot waveguide to have high mode confinement and a long propagation length, for which the objective function is defined as a figure of merit combining both propagation parameters.
Thin Film Deposition of Tb
:Ce by Pulsed Laser Ablation and Effects of Low-temperature Post-annealing
Kim, Kang Min ; Chung, Jun Ho ; Ryu, Jeong Ho ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 76~79
DOI : 10.3807/JOSK.2012.16.1.076
(TAG:Ce) thin films were successfully deposited by a pulsed laser ablation method on a quartz substrate, and low-temperature post-annealing effects on luminescent properties were investigated in detail. TAG:Ce thin films were analyzed by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The as-deposited films were amorphous, and post-annealing above
was required for crystallization. The post-annealed TAG:Ce thin films showed strong and broad emission bands around 542 nm and excitations at 451 nm, which all corresponded to transitions between the 4f ground level to the
excited levels of Ce ion.
Design and Development of an Ultralow Optical Loss Mirror Coating for Zerodur Substrate
Cho, Hyun-Ju ; Lee, Jae-Cheul ; Lee, Sang-Hyun ;
Journal of the Optical Society of Korea, volume 16, issue 1, 2012, Pages 80~84
DOI : 10.3807/JOSK.2012.16.1.080
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
. 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.