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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Optics and Photonics
Journal Basic Information
Journal DOI :
Optical Society of Korea
Editor in Chief :
Volume & Issues
Volume 19, Issue 6 - Dec 2008
Volume 19, Issue 5 - Oct 2008
Volume 19, Issue 4 - Aug 2008
Volume 19, Issue 3 - Jun 2008
Volume 19, Issue 2 - Apr 2008
Volume 19, Issue 1 - Feb 2008
Selecting the target year
Design of an Endoscopic Microscope Objective Lens Composed of Flexible Fiber Bundle and Gradient-index with a High Resolution and a Minimally-Invasive Outer Diameter
Jang, Sun-Young ; Rim, Cheon-Seog ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 87~94
DOI : 10.3807/HKH.2008.19.2.087
We present a new design for an endoscope objective lens composed of a lexible fiber bundle with 30,000 core, and a gradient-index (GRIN) objective lens with an optical adaptor. The characteristic of this objective lens is to be minimally-invasive to be able to insert easily in the internal organs of live animals. The GRIN lens has a small diameter and a very simple construction, which is selected with the diameter of 1.0 mm and numerical aperture of 0.5 to achieve a minimally-invasive outer diameter and a high resolution. The resultant designed lens shows the performance as follows; a lateral resolution of 1.63 um and diameters of 100% encircled energy of
for the on-axis and the off-axis image point, respectively. Also, we can present a cheap solution with a lateral resolution of 1.74 um and diameters of 100% encircled energy of
for the on-axis and the off-axis image point, respectively.
Autostereoscopic Display System Using a Variable Parallax Barrier
Wi, Sung-Min ; Lee, Seung-Hyun ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 95~102
DOI : 10.3807/HKH.2008.19.2.095
An advantage of parallax barrier displays is that they can also display 2D and 3D contents and can be automatically switched between the two types. But, as the viewer changes position, different views of the scene will be directed by the barrier to the visual system. Moving horizontally beyond a certain point will produce "image flipping" of the different views of the scene. These limitations make unavoidable the use of another autostereoscopic display solutions like eye tracking or increasing the number of views. In this paper, a method of the moving parallax barrier design is introduced to supplement a disadvantage of the fixed parallax barrier that provides observation at specific locations. For making the moving parallax barrier, the cross connector with 640 lines FPC is designed. A commercially available web camera is utilized to implement eye-tracking system and shows the experimental result.
Common-path OCT Image Using Partial Reflecting Probe
Park, Jae-Seok ; Jeong, Myung-Yung ; Kim, Chang-Seok ; Han, Jae-Ho ; Kang, Jin-U. ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 103~107
DOI : 10.3807/HKH.2008.19.2.103
Unlike conventional optical coherence tomography systems based on Michelson interferometer, we suggest a common-path OCT system, which does not include a separated configuration between reference signal and sample signal. We optimize the refractive index of partial reflecting probe to induce a balanced intensity of the reference signal. At the end of the probe, convex lens was optimally fabricated to get images of biological samples in the position of focus. Using the experimental system, we could get 2-D images of various biological samples.
Optical System Design Composed of Spherical SELFOC Lens and Aspherical Plastic Lens for Mobile Phone Camera
Lee, Yong-Sun ; Lee, Jong-Ung ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 108~115
DOI : 10.3807/HKH.2008.19.2.108
We designed optical systems for a mobile phone camera using a spherical SELFOC lens and an aspherical plastic lens. Since the radial index distribution gives an additional design parameter for optical design, an aspheric lens could be replaced by a spherical lens. The imaging performances of the design were compared with conventional 2P design composed of two aspherical plastic lenses. In the first stage of study, we designed 1GRIN 1P lenses by using commercially available SELFOC materials. But, the conventional 2P lenses had better performance than the 1GRIN 1P lenses. In the 1GRIN 1P designs, the performance depends on index variation of GRIN material, the larger variation gives the better performance. Hence, we tried to design by using fictitious GRIN materials which have large index variation. We found if the index variation could be increased to about 3 times that of currently available SELFOC materials, the 1GRIN 1P lens will have equivalent or better performance than the conventional 2P design.
Study on 3 Dimensional Images Using LED by PLS with No Viewing Zone Forming Optics
Choi, Kyu-Hwan ; Kim, Sung-Kyu ; Son, Jung-Young ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 116~121
DOI : 10.3807/HKH.2008.19.2.116
A two dimensional point light source array can replace both the viewing zone forming optics and the back light panel in the contact-type 3 dimensional imaging systems based on LC panels. This replacement can make the system structure of the 3 dimensional imaging systems no different from that of the conventional LCD and can reduce undesirable visual effects caused by the viewing zone forming optics. The problem with the point light source array is the visual quality deterioration of the system due to the non-ideal nature of the array.
Dual Backlight Unit Incorporating a Single Light Source Integrated with a Beam Splitting Reflector
Park, Chan-Kyu ; Lee, Hak-Soon ; Lee, Sang-Shin ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 122~126
DOI : 10.3807/HKH.2008.19.2.122
Dual backlight unit incorporating a single light source integrated with a beam splitting reflector was demonstrated, providing a surface light beam for both the keypad and the display section simultaneously. The reflector was realized by aligning a groove substrate with a matching cover, and a light guiding module comprising a stack of light guide panels and prism/diffuser sheets was attached to both sides of the reflector. A light emanating from the light source-placed in the middle of the substrate-undergoes a series of reflections through the reflector to reach the input of the light guiding module. Then it is transformed into a surface light beam, which is used to irradiate the keypad and display sections simultaneously. As for the accomplished dual surface light sources, the measured average luminance and the spatial luminance uniformity were respectively about
and 69% for the keypad section, and
and 79% for the display section.
Refractometric Glucose Biosensor Incorporating a Vertically Coupled Microring Resonator in Polymeric Waveguides
Kim, Gun-Duk ; Son, Keun-Sik ; Lee, Hak-Soon ; Kim, Ki-Do ; Lee, Sang-Shin ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 127~131
DOI : 10.3807/HKH.2008.19.2.127
A refractometric glucose biosensor incorporating a vertically coupled microring resonator in polymers was proposed and realized. The ring was covered with a target analyte of glucose solution with a certain concentration, so that its effective refractive index could be altered and, as a result, the resonance wavelength of the sensor was shifted. Therefore the concentration of the glucose solution can be estimated by observing the shift in the resonance wavelength. Two schemes were exploited for enhancing the sensitivity of the sensor. First, the effective refractive index of the polymeric waveguide used for the resonator sensor was adjusted to approach that of the target analyte as best as possible. Second, the ring waveguide, which serves as a crucial sensing part, was appropriately over-etched to enlarge its contact area with the analyte. The proposed resonator sensor was designed with the beam propagation method. The refractive indices of the core and cladding polymer involved were 1.430 and 1.375 respectively, leading to the waveguide's effective refractive index of
, which is faiirly close to that of the glucose solution of
. The prepared ring resonator with the
radius exhibited the free spectral range of 0.66 nm, the bandwidth of 0.15 nm, and the quality factor of 10,000. For the sensor operating at 1,550 nm wavelength, the achieved sensitivity was as great as 0.28 pm/(mg/dL), which is equivalent to 200 nm/RIU.
Analysis of Frequency Response of Piezo Stages and Scanning Path Monitoring/Compensation for Scanning Laser Optical Tweezers
Hwang, Sun-Uk ; Lee, Song-Woo ; Lee, Yong-Gu ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 132~139
DOI : 10.3807/HKH.2008.19.2.132
In scanning laser optical tweezers, high speed scanning stages are used to manipulate a laser beam spot. Due to the inertia of the stage, the output scanning signal decreases with increased frequency of the input signal. This discrepancy in the signals is difficult to observe since most of the energy from the laser beam is blocked out to avoid CCD damage. In this paper, we propose two methods to alleviate these problems. Firstly, frequency responses of piezo stages are measured to analyze the signal drops and the input signal is compensated accordingly. Secondly, an overlay of the scanning path is drawn on the live monitoring screen to enhance the visibility of the scanning path. The result is a drop-compensated scanning with clear path view.
Fabrication of the Single-Mode External-Cavity Laser using Micro Block Stacking Technique
Yoon, Hyun-Jae ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 140~143
DOI : 10.3807/HKH.2008.19.2.140
The integrated external cavity laser has been fabricated with a 1550 nm FP-LD, an optical filter, a micro ball lens and accurate ceramic blocks using a micro-block stacking (MBS) technique. The integrated external cavity laser module whose size is only
has been mounted on the TO-CAN package. For the case of the 1.8% transmission filter, the single mode characteristic has been obtained with the optical power of -27.1 dBm and the SMSR of 31.7 dB.
Wavefront Distortion caused by High Energy Laser Beam in the Relay Mirrors of the Laser Beam Director
Choi, Jong-Ho ; Kim, Yeon-Soo ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 144~149
DOI : 10.3807/HKH.2008.19.2.144
Thermal distortion of the laser mirrors which are the Coude mirrors of the laser beam director and the wavefront error caused by the thermal distortion are studied. Coude mirrors consist of three relay mirrors and one fast steering mirror. The mirrors have reflectivity of 99.5% with respect to the laser wavelength of
, and absorption of 500 W per second. Thermal distortion and its related wavefront errors are studied with laser beam irradiation for 5 seconds. For the relay mirror, the wavefront error is 334 nm_PV, 98 nm rms and for fast steering mirror,
An Improvement of the Extended Jones Matrix Expression for Analyzing Polarization Transmission Characteristics of a Uniaxial Medium
Ryu, Jang-Wi ; Shin, You-Sik ; Kim, Sang-Youl ; An, Sung-Hyuck ; Kim, Yong-Ki ;
Korean Journal of Optics and Photonics, volume 19, issue 2, 2008, Pages 150~158
DOI : 10.3807/HKH.2008.19.2.150
The exact transmission coefficients at the interface between a uniaxial anisotropic medium and an isotropic medium at? oblique incidence are derived by applying the extended Jones matrix method. When the birefringence of the uniaxial anisotropic medium is small (
), the exact transmission coefficients are compared with those by the conventional extended Jones matrix method by Yeh et al. They showed an excellent agreement with each other. In addition, using the exact transmission coefficients, we calculated the polarization characteristics of a light through a uniaxial medium to an incident light with arbitrary polarization state at? oblique incidence. We compared the transmittances of an unpolarized light through a pair of crossed o-type polarizers by two different methods and calculated the transmittance as the variation of the optical constants of the polarizers to evaluate of the extinction ratio. The polarization analysis method using the exact transmission coefficients can be applied to polarization characteristics of a light through a uniaxial medium with large birefringence as well as to liquid crystals and to optical anisotropic material.