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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 9, Issue 6 - Dec 1998
Volume 9, Issue 5 - Oct 1998
Volume 9, Issue 4 - Aug 1998
Volume 9, Issue 3 - Jun 1998
Volume 9, Issue 2 - Apr 1998
Volume 9, Issue 1 - Feb 1998
Selecting the target year
The electro-optic properites measurement of the side-chain polymer flim
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 215~220
We proposed an in situ measurement set-up and technique to measure the various electro-optic(E-O) properties of the E-O polymer. Using the proposed measurement set-up, the electro-optic effect and birefringence of unpoled side-chain E-O polymer induced by the strong dc and ac electric field were observed. The dependence of the E-O coefficients on the various poling conditions were measured with real time. To evaluate the thermal stability of the poled polymer the relaxation of the E-O effect was measured and the result was compared with well known polymer materials. The proposed measurement reduces the number of experimental steps and saves measurement time.
Multiphonon relaxation and frequency upconversion of
ions in heavy metal oxide glasses
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 221~226
Ternary heavy metal oxide glasses in the
system doped with
were prepared and their spectroscopic properties, such as radiative transition probability, calculated and measured radiative lifetimes and cross-sections of 1.5
emissions were analyzed. Enhanced quantum efficiencies of some electronic transitions were evident mainly because of the low vibrational phonon energy (
) inherent in the host glasses. This seems to be the main reason for obtaining the 2.7
luminescence which is normally quenched in the conventional oxide glasses. In addition, green and red fluorescence emissions were observed through the frequency upconversion processes of the 798 nm excitation. Non-radiative transition due to the multiphonon relaxation is a dominant lifetime-shortening mechanism in the 4f-4f transitions in
ion except for the
transition where a non-radiative transfer to band-gap excitation of the host glasses is dominant. Melting of glasses under an inert gas atmosphere and (or) addition of the typical glass-network former into glasses is necessary in order to enhance the quantum efficiency of the transition.
Strehl ratio and marechal criterion for gaussian pupil imaging system
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 227~230
The Strehl ratio(SR) expressions are derived from the diffration intensity distribution in a Gaussian pupil imaging system, and Marechal criterion is applied for the case of astigmatism aberration first and then to all the rest of the Seidel 1st order aberrations. The aberration criteria obtained are tabulated. In the case of Rayleigh's pupil, the same criteria are always smaller than Gaussian pupil, thus the latter is superior to the former.
Measurement of excitation efficiency and passively Q-switched characteristics of laser diode end-pumped Nd:YAG laser by using
:YAG as a saturable absorber
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 231~235
Passively Q-switched, laser diode(LD) end-pumped Nd:YAG laser was demonstrated by using
:YAG as a saturable absorber. In addition , we could calculate an excitation efficiency, which is an important parameter to evaluate the pumping geometry, directly by measuring the absorbed power in Nd:YAG at threshold condition. We found that output parameters such as average power, pulse duration, and repetition rate strongly depended on the low intensity transmission of
:YAG and driving current of lase diode. The maximum Q-switched output power of 1 W was obtained with 40 kHz repetition rate. The pulse duration was varied from 50 ns to 200 ns.
Second Harmonic Generation with a Type II Phase-Matched
and an External Ring Cavity
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 236~239
We constructed a frequency doubler with a frequency-stabilized Nd:YAG Laser, a nonlinear crystal KTP, and an external resonant cavity. Using type II phase-making method and a resonant cavity, one usually have a serious problem that the second harmonic conversion efficiency is decreased greatly, for under usual circumstances ordinary ray and extraorninary ray cannot be resonated in a cavity simultaneously. With the change of temperature and incident angle of KTP, we found an optimized condition for the phase-matching and double-resonance. As a result we produced 26 mW of green light with 318 mW of fundamental laser power from a cw Nd:YAG laser.
Study on a cavity ring-down spectrometer with continuous wave laser sources
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 240~244
Cavity ring-down spectroscopy (CRDS) is a high-sensitive laser spectroscopic technique capable of measuring concentrations of trace gases. We have demonstrated a new design of the CRDS spectrometer with a continuous wave (CW) laser. The ring-dwon signal is produced through blocking the incident CW laser by scanning the cavity length fast toward off-resonance iwth PZT (piezoelectric transducer). We have also measured an absorption spectrum of acetylene overtone transitions near 570 nm at the pressure of 2700 Pa, and the minimum detectable absorption coefficient has been found to be about
Quadratic polynomial fitting algorithm for peak point detection of white light scanning interferograms
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 245~250
A new computational algorithm is presented for the peak point detection of white light interferograms. Assuming the visibility function of white light interferograms as a quadratic polynomial, the peak point is searched so as to minimize the error sum between the measured intensity data and the analytical intensity. As compared with other existing algorithms, this new algorithm requires less computation since the peak point is simply determined with a single step matrix multiplication. In addition, a good robustness is obtained against external random disturbances on measured intensities since the algorithm is based upon least squares principles.
Generalized lens group conversion to their equivalent lenses
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 251~257
The equivalent lens conversion is extended to lens group conversion, and the more generalized conversion method is developed. The new conversion method can be used for hte direct thick-to-thick lens conversion. By using the equivalent lens conversion, a thin lens system can be converted into various thick lens system which have different axial thicknesses, but those converted lens systems have identical paraxial property and similar aberration characteristic. For an example, the equivalent lens conversion technique is applied to modification of a thelephoto lens design. The axial thicknesses of the front group elements of the system are reduced to 75% of their original values. The modified design by using the equivalent lens conversion has same focal length with original, and it has smaller aberration changes than the other design of which axial thicknesses are changed only.
Uncertainty improvement in measurement of mean diameter of 0.3-
-diameter polystyrene sphere by using quasi-elastic light scattering
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 258~263
Quasi-elastic light scattering is utilized to measure the mean diameter of the 0.3
-dimeter polystyrene sphere. The mean diameter of the polystyrene sphere is required to be known within the uncertainty of a few per centages. The systematic error has been considerably reduced by improving the system for the angle alignment and temperature measurement of cell. NIST SRM 1691 (0.269
: TEM; 0.275
: QELS) is measured to be 0.273
in mean diameter. Detailed description is given of the improved method and the resultant uncertainty, and the comparison of results with NIST is followed.
Visualization of luminescent radicals in the flame by image processing
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 264~269
The Measurement of concentration patterns for
, CH and OH radicals in the premixed propane-air flame could be managed through an image processing technique. This technique was applied to the three kinds of flames on a bunsen burner-mixtures of fuel to be lean, optimum and excessive respectively. The image processing system was complished by treating single wavelength flame images around the eac radical luminescence band, which was obtained by using a set of narrow band pass filters, an image intensifier, CCD and PC. It was possible to observe and predict the reaction zone and the concentration distribution of the radicals, Spatial distribution of each radicals in the raaction zone gave us enough informations to analyze the reaction mechanisms in
combustion process. According to this informations, the image of
radical exists at front zone, following the images of CH and OH radicals at downstream.
10 GHz wavelength tunable mode-locked filber ring laser configured with all polarization maintaining fiber
Korean Journal of Optics and Photonics, volume 9, issue 4, 1998, Pages 270~273
We have demonstrated the wavelength tunable ultrashort pulse fiber ring laser proposed the novel method for measuring the cavity loss from relaxation oscillation frequency and the pump power. To suppress the polarization instability the laser cavity is configured with polarization maintaining fibers and to control the center wavelength a 2.4 nm bandwidth tunable wavelength filter was inserted in the cavity. The laser has 8 picosecond pulse width, 10 GHz repetition rate and 1.2 mW average power in 1530-1560 nm operation range.