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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 11, Issue 6 - Dec 2000
Volume 11, Issue 5 - Oct 2000
Volume 11, Issue 4 - Aug 2000
Volume 11, Issue 3 - Jun 2000
Volume 11, Issue 2 - Apr 2000
Volume 11, Issue 1 - Feb 2000
Selecting the target year
The effect of phase modulation on the central peak intensity in an optical system
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 67~72
A lot of varIOUS studies are taking advantage of annular masks or various pupil filters to design optical systems such as a digital versatile disc (DVD) pick up head and precise scanning microscopy that have the superresolution beyond the diffraction limit. We considered both annular mask and pupil filter for the superresolution system. Since image quality is a function of annular width, position and modulation amount, we computel'lzed the optimized condition for the phase modulation and mvestigated the variation of lhe center peak: intensity for the phase modulated system From tills result, we were able to detenrune the best conditions for the annular apodizer, wluch give the maximum value of the center peak intensity_ We made especially sure that the phase modulated system have an excellent compensation for spherical aberration as it lllcreases. eases.
The effect analysis of birefringence of plastic f
Iens on the beam diameter
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 73~79
We measure a beam diameter of scan and sub-scan direction of LSD (Laser Scanning Urnt) which uses
lens produced by injecLion molding method as a scanning lens. While the measured beam diameter in scan direction, which is
, shows similar size comparing to the design beam diameter, the sub-scan beam diameter shows sIzable beam diameter deviation as much as 37 11m ranging from
. Injection molding lens has the surface figure error due to the shrinkage III the cooling time and the internal distortion (birefringence) due to the uneven cooling conditIOn so that these bring about wavefront aberration (i.e., the enlargement of beam size), and are eventually expre~sed as the deterioration of the pdnting image. In this paper. we first measure and analyze beam diameter, birefringence (polanzation ratio), and asphedcal figure error of mIens in order to know the principle cause of the beam diameter deviation in sub-scan directIOn. And Lhen. through the analysis of a designed depth of focus and a calculated field curvature (imaging position of the optical axis directIon) using the above figure elTor data, we know Lhat the birefringence IS the main factor of sizable beam diameter deVIation in sub-scan direction. ction.
Parabolic mirror test using Computer Generated Hologram
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 80~84
Parabolic almninium mlITOr of m.5('||'&'||'cent; 50 nun) was fabncated by a diamond tummg machine. Computer generated hologram (CGH) for the test of parabolic mirror was encoded by binary phase hologram Approximation of curved fringe to line was made by staircase encoding. After fringe data 1ransformed mto a Post Scnpt file. magnified master CGH was printed by a laser printer, and then it reduced to the photographIc film. Parabolic mirror was tested by Twyman-Green interferometer with CGH at VIewing arm. Its experimental result was compared with those of surface profile and auto-collimatIon test, and then the errors were analyzed.
Image quality evaluation of CRT Displays using SQRI method
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 85~90
The image quality of CRT displays is descnbed by the physical characteristics such as luminance, contrast, address ability, viewing distance, and so on. However, the final evaluation of rmage quality is deteITIlllled by not phYSICal data, but subjective perceived Image quality. Therefore the correlation is compared the score of subjective image qualIty accompli~hed by several persons with calculated SQRI (SQuate Root Integral) value uSlllg 4 kInds of CRT monitors. And the influence of tile physical chatac1eristics for subjective Image quality is analyzed on the basis of the validity of SQRI method as a metric for the evaluation of subjective image quality. ality.
Fiber optic circular polarizing mirror using polymer cholesteric liquid crystal and it's application in the mode-locked fiber laser
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 91~96
We propose a novel in-line fiber optic circular polarizing mirror utilizing cholesteric lIquid crystal (CLC) polymer [11m for the fiber laser applications. Ions matrix representation of this device has been derived and venfied experimentally. In a Fabry-Perot cavity configuration, a CLC fiber optic rmrror has been used to achieve longitudinal mode suppression as well as to obtain passively mode~locked laser operations with 630 fs laser pulses via nonlinear polarization evoluhon.oluhon.
Subtraction of source noise in a fiber-optic gyroscope operating at the proper frequency
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 97~101
We proposed and demonstrated a new scheme for subtracting the source excess noise from the output of the fiber-optic gyroscope. Unlike the previous methods, this scheme has an advantage of not requiring a delaying fiber for source noise detection and can be simply applied to fiber gyroscope operating at the proper frequency. By usmg this scheme. the proper frequency component of the source excess noise was subtracted from the gyroscope output. As a result, we obtained the reduction of noise by 12 dB (electrical) which was measured from the noise floor spectrum in the fiber gyroscope modulated at the proper frequency. We also obtarned !be random walk coefficient of thc gyro output reduced by a factor of 3.5. f 3.5.
Higher-order soilton puliton pulse generation and compression in dispersion decreasing fiber for optical time division multiplexing system source applications
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 102~107
We propose a new scheme for generating a pedestal-free, femtosecond soliton pulse train by utilizing quasI-adiabatic high order soliton pulse evolution in dispersion decreasing fiber in conjunction with the intermediate pedestal suppression stage. Compression factor over 280 was achieved from lOGHz sinusoidal input, to 176 is soliton pulse train. train.
Gain clamping system of erbium-doped fiber amplifier using differential ASE monitoring
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 108~113
This paper presents a simple but novel gain deviation detector scheme which can be used for general gain-clamping systems. By using the difference of ASEJprobe powers extracted from the edges of gain-flattened bandwidth, gain deviation of EDFA can be exactly detected regardless of the operating condition of a constructed EDFA. To prove the vahd1ty of the suggested scheme, we Implemented gain clamping systems on a single EDFA and cascaded EDFA's link and achieved sufficient gam-clamping performance without the elaborate measurement for tlIe determination of control parameters. eters.
A study on optical gain and output-coupling power of selenium vapour laser using isotope helium
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 114~118
The paper presents the effects of outpLlt-coLLpling power and small SIgnal gain of a He-Se+ laser by discharge of either
. A quartz plane-plate was installed to outpLlt-coLlple the laseI beam from the resonator in the eAperimental setup. The result shows tbat compared with those of ~He, tbe outPLlt-coupling power and small-signal gain of
increase in the most of the lines. EspeCIally, the small-signal gain of
for the strong lines (497.6 nm, 499.3 nm, 506.9 urn, 5176 nm, 522.8 mn, 530.5 nm) lies 25% higher than Ulat of 4He, and the output-coupling power doubles oubles
A novel mode shape converter for polymer Rib waveguide
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 119~122
We proposed a novel mode shape converter (MSC) that can effectively reduce the coupling loss between polymer rib waveguide and single mode fiber. The double-nb geometry that was used in the novel MSC converted an elliptical mode to circular mode and an circular mode to elliptical mode. This structure can be easily realized by using the typical fabrication process for polymer wavegUide. Simulation using a three dimensional beam propagation method showed that the novel MSC has a coupling loss of 0.079 dB/facet and total lllsertioll loss of less than 0.2 dB. .2 dB.
Measurement of losses in mirror using cavity ring-down method
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 123~129
We set up a loss measurement apparatus using cavity ring-down method to get the losses in mirror having a small absorption and scattering. The measured errors could be explained by the loss inhomogeneity of the position of the mirror included in the cavity, and we knew that the long~period measurement limit of apparatus is three days, the minimum error limit of Lhe term is 4 ppm, which were gotten by measuring the long-period and short-period decay time in both reference and test cavity. Also we determined the losses m various mirrors fabricated at our laboratory using the apparatus and we found that the losses in mirrors are quite different at their spatial positions. tions.
Configuration optimazation of a reflective bistable twisted-nematic cell for high contrast operation
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 130~134
In this paper, the configuration of a reflectIve bistable tWIsted nematic (BTN) liquid crystal cell is optmnzed for high contrast and high brightness operation. We searched for the optimum opncal parameters of a reflective BTN cell by calculating its optical performances at 3 wavelengths; red, green, and blue. By studying the effect of each optical parameter on the optical performances, we found that the angle of !he polmlzer IS more important than any other opnea! parmlleters iu the deSIgn of a reflective BTN cell. We fablicated a reflective BTN cell with a wide-band retardation Him, whose measmed contrast ratio is 10.6: 1. .6: 1.
10 Gb/sx16-channel WDM transmission over 640 km of domestic non-zero dispersion shifted fiber
Korean Journal of Optics and Photonics, volume 11, issue 2, 2000, Pages 135~138