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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 12, Issue 6 - Dec 2001
Volume 12, Issue 5 - Oct 2001
Volume 12, Issue 4 - Aug 2001
Volume 12, Issue 3 - Jun 2001
Volume 12, Issue 2 - Apr 2001
Volume 12, Issue 1 - Feb 2001
Selecting the target year
Generation and fluorescence measurement of HF* molecules excited by combustion of fluorine and hydrogen
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 153~157
Operation conditions for the generation of an HF laser driven by fluorine-hydrogen combustion were discussed by mc:asuring the intensities of excited HF* molecules. Optimum injection quantities of fluorine gas for the generation of fluorine atoms was two times the injection mole number of hydrogen fuel. Slit nozzles with two dimensional configuration were used for the production of excited HF* molecules. When the injection mole number of secondary hydrogen gas is 1.3 times the injection mole number of fluorine gas, the fluorescence intensities of excited HF* molecules show maximum values. alues.
Observation of dispersion-like signal based on velocity-selsctive saturated absorption spectroscopy and frequency stabilization of diode laser
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 158~164
We observed a velocity-selective saturated absorption spectrum when the pump beam intersects the probe beam at a finite angle with a saturated absorption spectroscopic configuration in the cesium vapor cell. And we also observed a dispersion-like signal by measuring the difference between two velocity-selective absorption spectra produced by two parallel probe beams intersected by one pump beam. The dispersion-like signal was changed with the crossing angle and the crossing position of the pump and probe beams and compared with the calculated result. The dispersion-like signal was used as a frequency discriminator, and the laser could be frequency-stabilized without any frequency modulation. As a result, the square root of Allan variance was
, for the sampling time of 1 s.of 1 s.
대칭 및 비대칭 binary filter가 수차를 포함한 광학계의 축상 GAIN에 미치는 영향
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 165~171
We discuss the influence of annular binary filters on the axial PSF of imaging systems which are apodized by a radiallysymmetric filter and have spherical aberration and coma. In this paper we consider a whole family of annular binary fIlters in two cases. First, the binary filters are composed of two transparent annuli of the same area. Second, the binary filters are composed of a central clear circle and a concentric annular aperture with area bigger than that of the inner circle. In order to investigate the influence of the proposed filters on the axial PSF, we may use the axial resolution gains, which evaluate in terms of the FWHM of the intensity in the focal region of an apodized imaging system in comparison with that corresponding to a nonapodized one. We evaluate the PSF for the conventional and confocal systems having an aberration. ation.
Optical perfornance depending on input wavefront distortion
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 172~176
Optical performance depending on the input wavefront distortion is analyzed in terms of StreW ratio. The amplitude of wavefront distortion at the optic axis that gives the system diffraction limited optical performance is described quantatively from the analysis of the Strehl ratio, which is obtained at the image plane using the input wavefront that is characterized by low and high spatial frequency. uency.
NO measurements in lean and soot flame using KrF laser
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 177~183
The KrF laser was employed to study NO fluorescence in lean-bum as well as in soot-bum flames. Blue-shifted NO fluorescence was observed in both of the flames. For both of the flames, the fluorescence intensity of NO and its relative background noise signal were measured with respect to the concentration of seeded NO molecule in the flame and the laser intensity. The results were analyzed qualitatively. Also, NO concentration distribution in the lean-bum flame was qualitatively determined from the intensity of the NO fluorescence. cence.
Design of ultra high speed ellipsometer using division-of-amplitude-photopolarimeter
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 184~189
The design of an ultra fast ellipsometer is suggested. It adopts the division-of-amplitude-photopolarimeter (DOAP) as the polarization state detector. It does not utilize any moving part such as the rotating polarizer(analyzer) or even any electronic modulation part like the piezo-electric phase modulator. Hence the time resolution of the present system is limited only by the response time of the photo-detector and electronic circuit as well as the analog-digital converter. The feasibility of the suggested ultra fast ellipsometer was tested and the response time with nano-second time resolution has been verified. Its future application to the investigation of kinetics including that of the phase-change optical recording media like GezSb2 Tes is discussed. ussed.
Research on the optimization of off-axis illumination condition and sub-resolution pattern size for the
rule dense pattern formation
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 190~199
In this paper, we have researched the depth of focus (DOF) and cutoff intensity of the
rule dense line'||'&'||'space pattern according to the various off-axis illumination (OAl) conditions in the optical system of 0.65 NA using ArF excimer laser (193 nm). We have also studied the variation of the DOF and cutoff intensity according to the sub-resolution pattern (hammer head type) size for optical proximity correction (OPC) applied to the capacitor pattern and the various OAl conditions in the same optical system. As a result, it is revealed that the cross type quadrupole or annular illumination is preferred to the conventional X type quadrupole for printing the
rule dense pattern. Also, we can investigate the optimal illumination condition and the size of ope sub-resolution pattern to keep a consistent DGF and cutoff intensity trends.
Design and characteristics of 10Gbps
64 ch. wavelength multiplexed optical signal amplification unit with 1530~1560 nm and 1570~1600 nm gain band
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 200~204
The structural design and the measured characteristics of optical signal amplification unit for 640 Gbps (10 Gbps
64 ch.) WDM transmission systems are reported. The unit is composed of two sub gain block units for the amplification of C-band (1530-1560 nm) and L-band (1570-1600 nm), respectively. Programmable microprocessors monitor the states of operation and optimize the optical output conditions. Each sub gain block unit can maintain total optical output power of +21 dBm with gain flatness of < 1 dB and noise figure of <7.2 dB for the input power in the dynamic range from-5 to +1 dBm.+1 dBm.
Constant inversion black box model of EDFAs including various loss mechanisms
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 205~211
We propose a constant inversion black box model of erbium-doped fiber amplifiers (EDFAs) for exact performance predictions for EDFAs operated in the gain-flattened condition. The validity of the newly proposed model was experimentally verified by predicting the performance of EDFAs for the L band, within 1.9% required pump power discrepancy. The role of ion pairing effects on the power conversion efficiency is also discussed. ussed.
The effect of extinction ratio, chirp and SPM on transmission performance of directly modulated 2.5 Gbit/s transmitter
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 212~218
We experimentally investigated the dependence of extinction ratio and chirp on bias current which was injected into DFB-LD in a directly modulated 2.5 Obitls transmitter. Through the abnormal dispersion transmission, we found that transmission power penalty is minimized at 8-10 dB extinction ratio (bias current at 1.5-1.8 fold above threshold current). Also, we discussed the relation between extinction ratio and self phase modulation (SPM) through the 240 km abnormal dispersion transmission. When SPM takes effect, we obtained the best receiver sensitivity for specific system configuration at 10.4 dB and 8.4 dB extinction ratio, below and above 200km transmission distance, respectively. ively.
Temporal characterization of femtosecond laser pulses using spectral phase interferometry for direct electric-field reconstuction
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 219~224
Spectral phase interferometry for direct electric-field reconstruction (SPIDER) was fabricated and used to characterize pulses from a Ti:sapphire oscillator. In the SPIDER apparatus, two replicas of the input pulse were generated with a time delay of 200 fs and were upconverted by use of sum-frequency generation with a strongly chirped pulse using a 8-cm-long SFIO glass block at a 30-11m-thick type II BBO (p-BaBz04) crystal. The resulting interferogram was recorded with a UV-enhanced CCD array in the spectrometer. The spectral phase was retrieved by SPIDER algorithm in combination with independently measured pulse spectrum and the corresponding temporal intensity profile was reconstructed with a duration of 19 fs. As an independent cross-check of the accuracy of the method, we compared the interferometric autocorrelation (lAC) signal calculated from the SPIDER data with a separately measured lAC. The conventional, but unjustified, method of fitting a sechz pulse to the autocorrelation deceivingly yielded a pulse duration of 15 fs. This systematic underestimation of the pulse duration affirms the need for a complete characterization method. From the consideration in this paper, we concluded that the SPIDER could provide an accurate characterization of femtosecond pulses. ulses.
Relaxation phenomena of electro-optic coefficient in P(VDF-TrFE) copolymers
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 225~229
Relaxation phenomena of the electro-optic coefficient in ferroelectric copolymer P (VDF- TrFE) were studied. The electro-optic coefficient of copolymers was measured by simple reflection method and the decay curves were fitted by KWW stretched exponentials. The copolymers poled near Tc. Were shown to be more stable than the copolymer poled at lower temperatures. Further, the relaxation time t depending on temperature was found to follow Arrhenius behavior and it was found that the activation energy of 50/50 mol% P (VDF-TrFE) copolymer is larger than that of 72/28 mol% copolymer. As a result, the ferroelectric copolymer with VDF of 50 mol% is was more stable.stable.
Determination of photorefrative constants in LiNbO
using second harmonic generation
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 230~234
We report a simple method for determining photovoltaic constant and conductivities of any photorefractive crytals which have no inversion symmetry by utilizing the electric field dependence of non-phase-matched second harmonic generation. New theoretical expression for the electric field dependence of Maker fringes is derived and space charge field can be determined using this from the observed change of intensity of second harmonic wave. The photovoltaic constant, dark conductivity and photoconductivity are easily deduced from an analysis of the measured relaxation behavior of space-charge field at two different light intensities. We demonstrate this method for
at 514.5 nm.4.5 nm.
Optical configurtion and fabriation for a reflective display using an antiferroelectric liquid crystal cell
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 235~239
In this paper, we propose an optical configuration of a reflective AFLC display mode using a half-wave AFLC cell in which inplane tilt angle is
. To check the validity of our design, we fabricate a reflective half-wave AFLC cell of which the in-plane tilt angle is
, and measure viewing angle and visible spectra characteristics. In the results, the half-wave AFLC cell in the reflective configuration exhibits wide viewing-angle as well as high brightness and contrast. trast.
Hybrid (refrctive/diffractive) lens design for the ultra-compact camera module
Korean Journal of Optics and Photonics, volume 12, issue 3, 2001, Pages 240~249
A high speed ultra-compact lens with a diffractive optical element (DOE) is designed, which can be applied to mobile communication devices such as IMT2000, PDA, notebook computer, etc. The designed hybrid lens has sufficiently high performance of less than f/2.2, compact size of 3.3 mm (1st surf. to image), and wide field angle of more than 30 deg. compared with the specifications of a single lens. By proper choice of the aspheric and DOE surface which has very large negative dispersion, we can correct chromatic and high order aberrations through the optimization technique. From Seidel third order aberration theory and Sweatt modeling, the initial data and surface configurations, that is, the combination condition of the DOE and the aspherical surface are obtained. However, due to the consideration of diffraction efficiency of a DOE, we can choose only four cases as the optimization input, and present the best solution after evaluating and comparing those four cases. On the other hand, we also report dramatic improvement in optical performance by inserting another refractive lens (so-called, field flattener), that keeps the refractive power of an original DOE lens and makes the petzval sum zero in the original DOE lens system. ystem.