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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
Electromagnetically induced absorption in Cs vapor
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 301~305
The electromagnetically induced absorpTIon (EIA) in the transition line, F=4
F'=5, of Cs
line was lnveslIgaled. We observed the large increase in atomic absorption due to cohelent interaction with two resonanllaser fields. The requuements of EIA in the Cs atoms were investigated experimentally. The magnitude of EIA signal dependIng on both laser jinewidth and the intensity of coupling laser was measured. Also we are able to observe the amplified absorption signal by incoherent optical pumping of atoms into the closed system.system.
The development of laser doppler vibrometer using DPLL for the detection of ultrasonic vibration
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 306~311
This paper deals with the development of Laser Doppler Vibrometer (LDV) that can mea~ure the tlequency and amphlude of the ultrasonic vibralion. Hc-Ne laser (632.8 om) is used as a light source, and Michelson interferometer in winch frequency of the objective beam is shIfted by Bragg cell IS adopted The frequency modulated signal centered at 40 MHz flom the PIN diode IS amplified. down-col1vel1ed to 2.5 MHz, filtered and digiLized. The voltage output that is proportional to the velocity of the vibratwg surface is obtawed using digItal PLL. A microprocessor is used to extract the frequcncy aud amplitude of the vibratIOn from the voltage output. It is found that the developed LDV can measure up to 300 kHz vibratIOn and the mlillmUITI measurable amplitude is I nm at 300 kHz. We believe thatlhis LDV can be used to measure the vibratIOn of the heavy electric maclllnery and micro-size structures. tures.
Surface roughness characteristics of the super-polished
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 312~316
Vole lllvesnguted the surface roughness charactenstics of the super~polished mirror substrate made by bowl-feed technique. in comparison with the case of fresh-feed technique. Fresh-feed techmque and bowl-feed technique were tried lor substrate surface polishing, and the surface roughne~s was estimated by phase-measunng interferometry. l11e slilface roughness of the substrate after bowl-feed procedure was Improved approxImately three times as fine as that after fresh-feed procedure. and tbe nns roughness of less than
and up to
at its best was obtained for the bowl-feed procedure. The surface roughness changes by (he bowl-feed technique. compated with tbe fresh-feeclleclmique. were analyzed witb tbe help of both 1 -dimensional roughne,>s profde and rougbness amplItude spect1U1l1 of the polished substrate, whIch ascertained that the final polishing partIcle size of the bowl-feed ptocedure was much smaller than that of the fresh~feed procedure. edure.
Self-compensation of the phase change upon reflection in two-wavelength white light interferometry for step height measurement
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 317~322
We present a compensation method of the phase change upon reflection in the scannll1g whIte light interferometry. which pracl1cally allows precIse 3-D profIle mappmg for compo~Ite target surfaces comprising of multipledissinular matenals. The compensation method estimates the vanatlon 01 pbase change with the spectral distribution of the light source through first-order approximation, and then diIectly compensates the measurement errors by perIormmg two-wavelength white light intetferomctric measurements. Experimental results prove that the proposed self-compensatIOn mcthod is capable of reducing the measmement error in step height gauging within
Design and deposition of two-layer antireflection and antistatic coatings using a TiN thin film
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 323~329
In this study we have calculated an ideal complex refractive index of a TiN trim used in a layer of anl1reilecnon (I\R) coatmg, [air
] in the visible. Also we simulated the rellectance of lwo-layer AR coating by varying the thicknesses of TiN and
layers, respecl1vely. The simolation results show that we can controllhe lowest reflectance and AR band of tile AR coating. The TIN fihns were fabricated by a RF magnetron sputtering apparalus. The chemical, structural and electrical properties of TiN fih11S were inveshgated by the Rutherford backscattering spech'oscopy (RBS), atomic force microscope (AFM) and 4-point probe. The optical properlies were inve,tigated by the spectrophotometer and vanable angle spectroscopic ellipsometer (VASE). The smface roughness of TiN flhns \vas
. TIle resistivity of TiN films was TEX>$360~730\mu$\Omega $ cm. The ,toichlOllletry of TiN film was 1'1: O:N = I: 0.65 :0.95 and ilic oxygen wa~ found on ilie smface. With these experimental and simu]al1on resulLs, we deposited duo: two-layer AR coating, [air
] and the refleClance was under 0.5% ill the regIOn of 440-650 run. 0 run.
40 GHz optical phase lock loop circuit for ultrahigh speed optical time division demultiplexing system
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 330~334
A new pha~e lock loop (PLL) IS proposed and demonstrated fat clock recovery from 40 Gblt/s time-dIvision-multiplexed (TDM) optical pulse tri.lin, The proposed clock lecovery scheme lmproves the Jitter effecl cOlmng from the clock. pulse laser of harmonically-mode locked flber laser The cross-corrdation frequency component between the optical Signa] and an optical clock pulse tram is deteCled as a fonr-wave-mixing (FWM) SIgnal generated in SOA. The lock-in freqnency range of the clod. recovery IS found to be within 10 KHz. 0 KHz.
Modeling and fabrication of
coarse WDM optical directional coupler using
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 335~339
coarse WDM opncal dIrectional coupler that conslsls of two idenlical straight channel waveguides in BK7 glass has been fabricated. The separatIOn between two channel waveguides is
and the wavegu.ide width is
. Especlally, we assumed that the index profile is Gaussian function and complementary error function in the width direction and depth direction, respectrvely. This directional coupler operating at
with crosstalk of 18dB is demonstrated and has the 16 mm long length with 12.6 mm coupling region.region.
Structural dependence of the effective facet reflectivity in spot-size-converter integrated semiconductor optical amplifiers
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 340~346
Traveling wave type semiconductor optical amplifiers integrated with spot-size-converter (SSC-TW-SOA) have been extensively studied for the improvement of coupling effiClency With single-mode fiber and fO! the cost reducClon 111 a packaging In tlIis paper the slructural dependence of the spot-slZe-converter on the effective facet reflectlvllY
was experimentally as well as thcoretienlly mvestlgated. It was shown that not only a sufficient mode-conversion in a sse region along the latersl and tran~verse directions but also an introductIOn of angled-facet were very essential in order to reduce
Very small ripple less than 0.1 dB in an amplified spontaneous emission spectrum was observed with the fabncated SSC-lW-SOA which consists of the wrndow length of
, facet angle of
, and antlrelleetioll-coated facet of ] % reflectivity.tivity.
Frequency stabilization of diode lasers using a ultra-stable reference cavity
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 347~352
We have stabIhzed the laser frequency of a commercial dIode laser using a ULE (Ultra-low expansion material) reference cavIty and the cunent modulation charactenstics of the dIode itself The liuewIdth of the frce running laser was about a 1 MHz (rms) for a sampling time of 1 s and the drift rate was 300 kHz/s. Vvhen the laser is locked to oue sIde of the transmission signal from the ULE reference cavity, the lincwidth was reduced to 46 kHz (nus) for a sampling time longer than 10 ms. The root Allan variance was less than 2 kHz for a sampling time langeI than10 ms. 10 ms.
Theoretical analysis improved cavitity design of a 10 GHz harmonically mode-locked Er-doped fiber laser
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 353~359
A harmonically mode-locked fiber ring laser cavlty was theoretically analyzed. The measured charactenstlcs of a 10 GHz erbium-doped fiber ring laser were used as a basis of the theoretical analysis. From the nonlinear Schroedinger equation of an actively mode-locked erblUm-doped fiber laser. the effects of the components inside the laser cavity have been analyzed includmg nonlinear effects from group-velocity dispersion (GVD) and self-phase modulation (SPM). Usmg the analysls. we have designed a laser cavity with minimum pulsewidth and chirp by changing the intracavity optical intensity and the bandwidth of the filter. In the new design, the chirp i, reduced by 2 times and the pulsewidth by 2A times. compared to the laser used in the experiment. iment.
A femtosecond Cr:LiSAF laser pumped by semiconductor lasers
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 360~364
We demonstrate self-starting passIve mode locking of a Cr:LiSAF laser, using a SCIDlconduclor Saturable Absorber Mirror (SESAM), Two high-power red semiconductor lasers (Coherent S-67-500C-100-H) of wavelength 667 nm and maximum power of 500 mW were used as pump lasers, The cavity has 10 cm radius-ai-curvature folding minors, two SF 10 prisms, a 99% reflectivity output coupler and a SESAM at dIe focus of a 10 cm radIus-at-curvature mirror. We used the laser crystal in BrewsterBrewster shape with 1 5%
ion concentration and the length of 6 mm, An X-shaped resonator was used to compensate the astigmatism induced by tile crystal. The structure of the SESAM cOllSists of 30 pmr of
layer, wi1l1 a 10 nm GaAs quantum well situated in the topmost layer Output spectra were centeled at 833 nm, with 4 nm spectral bandwidth and pulse width was measured to be 220 fs, Output power of 3 mW is obtained at a pump power of 800 mW. 00 mW.
Characteristics of four-pass Ti:sapphire laser amplifier and amplified spontaneous emission
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 365~370
We have constructed a collinear four pass Ti.sapphire laser amplifier by usmg polmization effect When we pumped the mnplifier with 188 mJ second harmonics of Q-switched Nd:YAG laser, we observed that a 450 mW 1l1cident cw Ti:sapphire laser beam is amphfled to pulse with energy of 34 mJ and pulse width (FWffM) of 25 os. We could mmllmze the a.mplified spontaneous emission by simple method of rotating the Tbapphire amplifier rod er rod
Area storage density in holographic disk memories using rotational, angular, and spatial multiplexing methods in combination
Korean Journal of Optics and Photonics, volume 11, issue 5, 2000, Pages 371~376
For multi-hologram recording especially in a dIsk-shaped storage medium. we had studied a simple cost-effective method to unplement the rotational, angular, and ,patial multiplexmg techniques together in order to enhance the area storage density. Holographic storage with both rotational and angular multIplexing was realized by controlling the rderence beam directly with a pair of wedge prisms. whlie the storage WIth spatIal multlplexmg by shIfting the storage medium. In thIS paper \ve show that lhe area storage density of our system is strongly dependent on f numbers of the lenses in the srgnal and reference anns, and also show that the area storage densrly becollles maximal when the f number of the lens in the signal arm is approximately twice as long for a given f number of the lens in the reference emn. e emn.