• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.461-466
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• 2002

Fiber-optic comb filters using a side-polished fiber coupler are proposed as multi-channel isolation filters on wavelength division multiplexing systems. We have demonstrated that the coupling efficiency between two waveguides is improved by the intermediate coupling layer in spite of the decrease of the optical power transfer between two waveguides due to the high-order modes of the overlay waveguide coupled with the side-polished single-mode fiber. When LiNbO$_3$with a 200-${\mu}{\textrm}{m}$-thickness was applied as a planar-overlay-waveguide, the comb filtering characteristics with a 4 nm-channel-spacing were achieved and the maximum power coupling occurred at the 1-${\mu}{\textrm}{m}$-thickness and the refractive index in range 1.52 to 1.53 of an intermediate coupling layer. If the intermediate coupling layer is optimized, an extinction ratio with more than 20 dB can be obtained. These experimental results are in good agreement with the BPM simulation.

• Korean Journal of Optics and Photonics
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• v.3 no.3
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• pp.198-202
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• 1992

Silver ion-exchanged glass waveguide with its large surface index difference and shallow depth is suitable to be used for the hybrid integration of semiconductor device and glass waveguide using the semiconductor film grafting technique. We report characteristics of the planar and channel glass waveguides exchanged in the diluted silver nitrate melt in the visible and infrared spectral region. Especially, we determined the fabrication parameters for single-mode channel waveguide at 1.5.$\mu$m, an important wavelength in the optical communication. Directional couplers with several different configurations were fabricated, and their 3 dB coupling length was determined as a function of wavelenGh and polarization.

• Macromolecular Research
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• v.12 no.3
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• pp.290-292
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• 2004

Multimode channel waveguides were fabricated using a direct UV patterning technology from thick films deposited by the one-step dip-coating of an organic/inorganic hybrid material (ORMOCER(equation omitted). The core size of the covered ridge waveguide was 43${\times}$51 $\mu\textrm{m}$$^2$; the waveguides can be readily prepared for multimode applications by direct UV patterning. The waveguides exhibited smooth surface profiles and a low optical loss of 0.07 ㏈/cm at the most important wavelength (850nm) used for optical interconnects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.275-277
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• 1999

A application possibility of photoresist flexible film for optical waveguide is proposed and described. The optical waveguide dimensions that is consists of Mach-zehnder interferometric and single channel waveguide based on the single-mode conditions in LiNbO$_3$ device was utilized and fabricated by wet etching technique. This Polymer material for core layer is SU-8/5O(Microchem.) and its refractive index from prism couping method was measured about 1.59 thickness about 10${\mu}{\textrm}{m}$ at wavelength 0.6328${\mu}{\textrm}{m}$. From the results, this work can show the possibility of fabricating a flexible optical waveguide in the field of integrated optics.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.502-504
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• 1989

An electro-optic cutoff modulator with self-aligned electrode that utilizes a single-mode proton-diffused well-guided channel waveguide in a X-cut Y-propagating $LiNbO_3$ substrate is reported. The self-aligned electrode is formed during proton diffusion process of itself. Nearly linear voltage-intensity relationship has been observed. Over 90 % modulation has been achieved with applied voltage of 25 V.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.156-157
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• 2003

The wavelength converter is considered to be a key element of future dense WDM optical networks. It enables wavelength reuse and resolves contention problem. Moreover, the tunability of the wavelength converter enhance the flexibility of network systems by facilitating reconfigurable dynamic wavelength routing. In order to achieve optically tunable wavelength conversion, we recently proposed and experimentally demonstrated wavelength conversion and tuning based on cascaded sum and difference frequency generation in a Ti：PPLN channel waveguide. (omitted)

• ETRI Journal
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• v.31 no.2
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• pp.228-230
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• 2009

InP-based planar waveguide 48-channel concave grating demultiplexers with a channel spacing of 0.8 nm (100 GHz) are described and demonstrated. Polarization insensitivity and flattened spectral response are successfully achieved by the introduction of a polarization compensator and a two-focus grating, respectively. The fabricated device shows a polarization-dependent wavelength shift of less than 20 pm and a -3 dB spectral width of about 0.55 nm (68.75 GHz) over all channels.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.269-273
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• 1990

The proton conserving effect of diffusion with self-aligned SiO2-cladding is investigated by infrared transmission spectra. Based on the proton conserving effect, proton-diffused channel waveguides with self-aligned SiO2-cladding substrates. And an electro-optic cutoff modulator with self aligned electrode that utilizes a single-mode proton-diffused channel waveguide in a Y-cut XX-propagating LiNbO3 substrate is fabricated. Over 20 dB extinction has been achieved with applied voltage of 15V.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.317-322
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• 2006

A polymeric arrayed waveguide grating (AWG) has been proposed and demonstrated by exploiting the nanoimprint method. A PDMS(polydimethylsiloxane) stamp with device patterns engraved was developed out of a master mold made of quartz glass. The device was fabricated by transferring the pattern in the PDMS stamp to a spin-coated polymer film without using any etching process. The device had 8 output channels, while the center wavelengths of each output channel were positioned from 1543.7 nm to 1548.3 nm with the spacing of 0.8 nm. The achieved average channel crosstalk and the 3-dB bandwidth were about 10 dB and 0.8 nm respectively.

• ETRI Journal
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• v.25 no.6
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• pp.535-537
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• 2003

We propose a rigorous 2D approximation technique for the 3D waveguide structures; it can minimize the well-known approximation errors of the commonly used effective index method. The main concept of the proposed technique is to compensate for the effective cladding index in the equivalent slab model of the original channel waveguide from the modal effective index calculated by the nonuniform 2D finite difference method. With simulations, we used the proposed technique to calculate the coupling characteristics of a directional coupler by the 2D beam propagation method, and the results were almost exactly the same as the results calculated by the 3D beam propagation method.