Go to the main menu
Skip to content
Go to bottom
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 8, Issue 6 - Dec 1997
Volume 8, Issue 5 - Oct 1997
Volume 8, Issue 4 - Aug 1997
Volume 8, Issue 3 - Jun 1997
Volume 8, Issue 2 - Apr 1997
Volume 8, Issue 1 - Feb 1997
Selecting the target year
Fabrication and studies on the properties of a spinning-disk confocal microscope
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 255~259
In this paper, the result of a performance study on a home-built spinning disk type confocal microscope is presented. The confocal microscope was fabricated with a Nipkow disk made of the made of the microfilm. The throughput of the disk was 0.5%, allowing the observation of specimen with higher reflectivities only. A laser diode at 692.7nm was used as the light source. The topographic structures of a PC ROM and the CD ROM were observed with sufficient reliability, while the effect of the convolution of the beam size with the finite object size was found dominant. Also the shadowing effect by the etched pattern was observed.
Polarization property of dichromated gelatin hologram and it's application to holographic polarization separation element
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 260~266
Holographic optical elements for polarization separation (HPS) are fabricated in a dichromated gelatin(DCG) thin film of 7
thickness. The polarization properties of HPS is characterized by measuring diffraction efficiency with several physical parameters like exposure time, incident angle and read-out polarization angles. The experimental data are compared with theoretical results based on Kogelnik's coupled wave theory, which shows good agreement. It is also found that the HPS element has a very high extinction ratio of polarization over 500:1 for S and P polarizations, respectively, with He-Ne laser wavelength. We also propose an optical switch optical interconnects by using HPS elements.
Simultaneous measurement of in-plane and out-of-plane displacement using holographic interferometry
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 267~276
We set up a four-wave holographic interferometer using a symmetric dual-beam illumination which is to measure in-plane and out-of-plane displacement simultaneously. In order to acquire the displacement phase map we applied the phase-shifting method and removed the noise of the phase map with least-squares fitting. In this approach the access to information relative to both the difference and sum of phases existing in the two arms of four-wave holographic interferometer was allowed. As a result, in-plane and out-of-plane displacement was measured to the accuracy of λ/40 and λ/100, respectively at λ=632.8nm
Complex refractive index of PECVD grown DLC thin films and density variation versus growth condition
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 277~282
The complex refractive index of Diamond-like Carbon (DLC) thin films, which can be applied to optical devices or electrical devices, have been determined using optical methods. DLC thin films are grown on Si(100) substrates and vitreous silica substrates respectively, using the technique of plasma enhanced chemical vapor deposition (PECVD). The spectroscopic ellipsometry data(
) and the transmission spectra of these DLC films are obtained. These optical spectra are analyzed with the help of the Sellmeier dipersion relation and a quantum mechanically derived dispersion relation. Using spectroscopic ellipsometry data at their transparent region, the refractive index and the effective thickness of DLC films on vitreous silica are model calculated, Then the transmission spectra are inverted to yield the extinction coefficient spectra k(λ) at absorbing region. These spectra are fit to the quantum mechanical dispersion relation and the best fit dispersion constants are determined. The complex refractive indices are easily calculated with these constants. The spectroscopic ellipsometry data at the absorbing region in model calculated to give the packing densities and the degrees of surface microroughness of DLC films. Discussions are made in correlation with the growth condition of DLC films.
Scattering measurement of dielectric high reflection mirrors by TIS method
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 283~290
Scattering measurement on high reflection dielectric multilayer mirrors deposited on quartz substrate in a vacuum chamber were performed using a total integrated scattering method. Scattering of (Ta
) multilayer mirrors deposited at 250-30
was 0.048-0.050% and did not change with an annealing at 30
for 4 hours. On the other hand, scattering of (TiO
) multilayer mirror at 25
was 0.029% and it showed the heavy tensile stress after an annealing. The rms roughness of (Ta
) multilayer mirror was almost the same as that of (TiO
)multilayer mirror. The column size of Ta
film was smaller than that of TiO
film and the packing density of (Ta
) multilayer mirrors was higher than that of (TiO
) multilayer mirror. It seems that the higher packing density and smaller column size of Ta
films lead to more scattering.
Slotted type copper ion laser
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 291~296
The slotted type of hollow copper cathode was constructed and tested for its geometric stability and usability for laser operation at 780nm. The peak output power of copper ion laser emission was measured for different operating conditions. The IR-laser power was dependent on the parameters of the geometry of the hollow cathodes, discharge current and gas fillings. The peak power decreased with increasing neon pressure over 60%. One reason for this decrease in output power may be conjectured as hier due to the decreasing population of the upper laser level. The copper ion laser transition at 780 nm populated at the 5p level. The hollow cathode copper ion laser is operated in He and Ne mixture by electric discharge excitation and could be operated for more than 100 hours with only a 35% drop in the output power(2.8mW cw for 9.6cm active length).
Controlled beam divergence in a hemiconfocal resonator copper vapor laser
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 297~302
A hemiconfocal resonator equipped with an intra-cavity adjustable aperture and a beam splitter has been studied experimentally to achieve a controlled low beam divergence operation in a vapor laser system. The dependences of output characteristics both on the aperture diameter and on the angle of beam splitter have been investigated. By adjusting the aperture diameter from 14mm to 2mm to 2mm, we were able to reduce the beam divergence from 3.1 mrad to 0.25 mrad and achieved the 8-times increase in the far-field power density.
Analysis of the oscillation condition optimized at laser-diode end-pumped solid-state laser
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 303~307
The energy transfer of a laser-diode-pumped Nd : S-VAP laser was detected by the photoacoustic technique using a PZT detector. The photoacoustic method suggests an effectvie approach to understand the energy transfer mechanism of the laser cavity, and to find out the optimum output coupler of the oscillator with comparative ease.
An array of dark spatial solitons generated by an adiabatic amplification of nonlinear refractive index with the beam propagation distance
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 308~314
We have studied the generation of an array of dark spatial solitons in a self-deforcusing medium. Unlike a single fundamental dark spatial soliton, we show numerically that the generation of an array of dark spatial solitons from a spatially sinusoidal input beam needs an adiabatic amplification of nonlinear refractive index with the beam propagation distance. In experiment, we establish a Mach-Zehnder interferometer for making the sinusoidal input beam and use a cylindrical lens for the adiabatic amplification. We observe that the dark soliton's dip-width becomes narrower and the background intensity distribution becomes flatter with increasing the nonlinearity.
Beam deflection using photorefractive volume grating in Ce-SBN:60 crystal
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 315~319
In photorefractive crystals, light deflection is achieved by dynamic photorefractive volume grating, which is induced by the interference of two writing beams. In this paper, we implemented and analyzed the light deflector using Ce-SBN:60 crystals, which is doped with CeO
and photorefractive effect is induced by low intensity. And we measured maximum coupling coefficient, effective charge density, diffraction efficiency as the intensity ratio and response time.
Construction and characterization of broadband erbium-doped fiber sources for gyroscope
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 320~326
Broadband sources for fiber-optic gyroscope were constructed using erbium-doped fibers. Output power, linewidth, and mean wavelength were compared between four different source configurations. Among them, double pass configuration exhibited the highest output power, as high as 5.5 mW with 25 mW pumping at 1.48
wavelength. It also showed nearly zero sensitivity of mean wavelength for the variation of pump power when a sufficient pumping was provided. Amplifier/Source configuration resulted in the highest detected power(power received by the gyro detector) that is more than 100 times larger than those of the other configurations, though it was the lowest of source output power. As the feedback level increased, the source power decreased while the linewidth increased, and mean wavelength varied significantly which would affect the scale factor of the gyroscope.
Fabrication and characterization of 1.55
m SI-PBH DFB-LD for 10 Gbps optical fiber communications
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 327~332
We fabricated the high speed 1.55
distributed feedback laser diodes (DFB-LD) using both two-step mesa etching process and semi-insulating InP current blocking layers. The devices characteristics were threshold current of ~15mA, slope efficiency of ~0.13mW/mA, and dynamic resistance of ~6.0Ω, with as-cleaved facets. The fabricated DFB-LD showed the single longitudinal mode with more than 40dB up to 6
(CW condition), emitting at the wavelength of 0.546
. The -3dB bandwidth was >10㎓ at the driving current of 27mA, and the maximum -3dB bandwidth was ~18㎓ at 90 mA current, showing the superior frequency response of SI-PBH DFB-LD. In the 10Gb/s transmission experiment for 1.55
DFB-LD module, maximum 10 km of single mode fiber(SMF) or 80 km of dispersion shifted fiber (DSF) could be transmitted with error free.
Novel dual-grating strain sensor signal processing technique using an unbalanced Mach-Zehnder interferometer
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 333~339
We fabricated a sensor head which consists of spliced different-diameter fiber gratings for discrimination between strain and temperature. Because the fibers were drawn from the same preform, their temperature characteristics were the same but not for strain sensitivities which are inversely proportional to fibers cross-sectional areas. In measurement range of 0-1500
strain and 20-10
, we could obtain, by using the matrix calculation, the unknown physical quantities within 10% of calculation error compared with the micrometer and thermocouple values. To improve the strain measurement accuracy, we suggest a new, novel method which deploys an unbalanced fiber Mach-Zehnder interferometer. This new signal processing technique converts the strain information to interference signal amplitude variation, temperature-independently. we obtained measurement accuracy nearly 80 times better than that obtainable with the conventional optical spectrum analyzer usage.
Optical tunable wavelength add/drop multiplexer employing piezoactuated fiber Bragg gratings for WDM system
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 340~344
We proposed and demonstrated a tunable wavelength optical add/drop multiplexer(OADM) employing piezoactuated fiber grating pairs and polarization beam splitters. We used piezostack act as a fiber stretcher, using the fact that the resonant wavelength of the grating can be controlled by the axial strain along the fiber grating. The polarization controlled configuration showed high stability because the reflected signals from the two identical gratings are dropped or added not by interference but by polarizations of the beams. We could add and drop not noly 1549.3nm signal channel(original gratings), but also 1550.1nm(tuned gratings) with PZT actuators and in both cases, we found that the rejection of adjacent channels was more than -26dB, and signal leakage at the gratings was less than -34dB.
The characteristics and optimization of submicron optical mask using electromagnetic scattering effect
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 345~352
Recently, in designing optical mask such as 4GDRAM, the scattering effect of electromagnetic wave must be considered. For this reason we claculated directly the mask function using the finite difference time domain(FDTD) method. The modification of image theory with this new mask function could explain clearly the scattering effect at the etched side wall of the submicron optical mask. The characteristics of the various type of alternating PSM were investigated. According to the simulation, the dual wet etch process was the most useful fabrication technique to overcoe the light scattering off at the shifted opening.
Fluorescence photon counting rate as a function of dye concentration: Effect of dead time of photon detector
Korean Journal of Optics and Photonics, volume 8, issue 4, 1997, Pages 353~355
A single molecule detection system, which consists of confocal fluorescence microscope and single photon counter, has been used to observe the dye concentration dependence of photon counting rate. With increasing concentration, a saturation effect of counting is observed and demonstrated on the basis of the dead time of photon detector. The equations presented here show the relations between the counting rate and some parameters such as probe volume, quantum efficiency of detector, and fluorescence photon number entered onto detector. The signal-to-noise ratio is also discussed briefly.