• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.149-154
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• 1996

We propose the concept of incident angle of complex number and analyze planar optical waveguides by applying the concept. The incident angle of complex number is concerned with the modeling of prism-gap-waveguide structures. It is shown that, when optical waveguides are analyzed by use of the transfer matrix method, the proposed concept enable us to find solutions faster and more accurately than ghatak's method which introduces the leaky structure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.3
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• pp.267-272
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• 2006

Optical waveguide based on symmetric and asymmetric Mach-Zehnder interferometer(MZI) type was designed, fabricated and measured the optical characteristics for the application of biosensor. The wavelength of the input optical signal for the device was 1550 nm. And the difference of refractive index was $0.45\;{\Delta}\%$ between core and cladding of the device. The TM(Transverse Magnetic) mode optical properties of the biosensor were analyzed with the refractive index variation of gold thin film deposited for overclad. Nowadays, nano-photonic crystal structures have been paied much attention for its high optical sensitivity. There is a technique to realize the structure, which is called Dip-Pen Nanolithography(DPN) process. The process requires a nano-scale process patterning resolution and high reliability. In this paper, two dimensional nano-photonic crystal array on the surface was proposed for improving the sensitivity of optical biosensor. And the Dip-Pen Nanolithogrphy process was investigated to realize it.

• Korean Journal of Optics and Photonics
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• v.9 no.3
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• pp.156-161
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• 1998

We developed aerosol flame deposition method and made stress-free Pyrex-based optical waveguide on silicon substrate using this method. Zr is doped to control the refractive index of Pyrex waveguide layers. The refractive index of the film changes from 1.460 to 1.475 as the content of Zr changes from 0 to 3 wt%. Er is doped to see the possibility of applying this Pyrex waveguide as PLC-type (Planar Lightwave Circuit) optical amplifier. The refractive index of the film changes from 1.460 to 1.465 as the content of Zr changes from 0 to 1 wt%. Light launching using a prism coupler to the fabricated waveguide showed good quality for application to PLC. The polarization dependence of refractive-index of the Pyrex film is measured to be less than $2{\times}10^{-4}$.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.457-460
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• 1988

We present here a numerical solution for obtaining propagation characteristics including lossess for various modes of an multi-layered optical waveguide structure. The method is based on transmission line analogy. A comparison with other method shows the our results are accurate and simple.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.130-134
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• 2016

The influence of Au/Ni-based contact formed on a lightly-doped (7.3×1017cm−3, Zn-doped) InGaAsP layer for electrical compensation of surface plasmon polariton (SPP) propagation under various rapid thermal annealing (RTA) conditions has been studied. The active control of SPP propagation is realized by electrically pumping the InGaAsP multiple quantum wells (MQWs) beneath the metal planar waveguide. The metal planar film acts as the electric contact layer and SPP waveguide, simultaneously. The RTA process can lower the metal-semiconductor electric contact resistance. Nevertheless, it inevitably increases the contact interface morphological roughness, which is detrimental to SPP propagation. Based on this dilemma, in this work we focus on studying the influence of RTA conditions on electrical control of SPPs. The experimental results indicate that there is obvious degradation of electrical pumping compensation for SPP propagation loss in the devices annealed at 400℃ compared to those with no annealing treatment. With increasing annealing duration time, more significant degradation of the active performance is observed even under sufficient current injection. When the annealing temperature is set at 400℃ and the duration time approaches 60s, the SPP propagation is nearly no longer supported as the waveguide surface morphology is severely changed. It seems that eutectic mixture stemming from the RTA process significantly increases the metal film roughness and interferes with the SPP signal propagation.

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.50.4-50.4
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• 2004

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.10
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• pp.1584-1590
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• 1989

In this study, a planar waveguide has been fabricated on a Y-cut LiNbO3 substrate by the Ti indiffusion technique and its guiding characteristics are measured by bright M-line spectroscopy. Using the photolithography method, an electro-optic grating modulator with interdigital electrodes has been fabricated by depositing Al on the Ti:LiNbO3 planar waveguide. And the beam intensity diffracted by the grating is measured as the applied voltage is increased.

• ETRI Journal
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• v.28 no.6
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• pp.739-744
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• 2006

In this paper, we report numerically calculated results of testing a temperature-insensitive refractive sensor based on a planar-type long-period waveguide grating (LPWG). The LPWG consists of properly chosen polymer materials with an optimized thermo-optic coefficient for the core layer in a four-layer waveguide structure. The resonant wavelength shift below the spectral resolution of the conventional optical spectrum analyzer is obtained accurately over a temperature change of ${\pm}7.5^{\circ}C$ even without any temperature control. The refractive index sensitivity of the proposed grating scheme is about 0.004 per resonant wavelength shift of 0.1 nm for an optimized thermo-optic coefficient.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.524-529
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• 2000

Silica slab wavegudie was fabricated on Si substrates by FHD for planar optical passive devices. The slab waveguide consists of lower clad and core layers, where core layer index is controlled by GeO2 addition. Doping of GeO2 in silica is difficult because of the low deposition density due to nonspherical particle generation in FHD process. Silica core particles deposited at various conditions such as flame temperature and substrate scanning were analyzed by SEM and TEM. As the flame temperature increased, the surface roughness of the core layer was decreased up to 3.6 nm after consolidation. Index difference and thickness of core of slab waveguide were 0.3%, 8$\mu\textrm{m}$ respectively. Measured optical loss at TE mode was <0.04 dB/cm at 1.3$\mu\textrm{m}$ and <0.06 dB/cm at 1.55$\mu\textrm{m}$.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.221-222
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• 2007

The UV laser trimming can be useful to have an accurate performance specification of the passive waveguide devices. In order to measure the change of the refractive index of polymer overclad layer under the irradiation of uv light in a high precision Bragg grating is fabricated on the silica core of planar waveguide and the corresponding transmittance spectrum was analyzed. An effective refractive index change of $4.7x10^{-5}$ was obtained for a straight waveguide when its $60{\mu}m$-thick overclad was irradiated by UV laser pulses of its total fluence 24 $J/cm^2$.