• ETRI Journal
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• v.27 no.3
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• pp.337-340
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• 2005

A spot-size converted Fabry-Perot laser diode (LD) was flip-chip bonded to a silica-terraced planar lightwave circuit(PLC) platform to examine the effect of the silica terrace on the heat dissipation of the LD module. From the measurement of the light-current characteristics, it was discovered that the silica terrace itself is not a strong thermal barrier, but the encapsulation of the integrated LD with an index-matching polymer resin more or less deteriorates the heat dissipation.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.826-833
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• 2004

In this study, photosensitivity dynamics in SiO$_2$ glass with the composition similar to that of silica Planar Lightwave Circuit (PLC) devices was investigated as a fundamental study prior to the device fabrication. Silica bulk glasses with similar composition to the core layer of PLC devices were prepared with variable composition of B$_2$O$_3$. The photosensitivity in boron and germanium co-doped SiO$_2$ glass yields refractive index change $\Delta$n as high as 10$\^$-3/. However such index modulation disappeared after annealing. From the result of annealing experiment and W absorption / Raman spectra, we conclude the compaction model is applicable to our glass system.

• ETRI Journal
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• v.28 no.1
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• pp.103-106
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• 2006

We have fabricated a planar lightwave circuit (PLC) hybrid-integrated optical sub-assembly of a triplexer using a thin film filter (TFF)-attached wavelength division multiplexer (WDM) and photodiode (PD) carriers. Two types of TFFs were attached to a diced side of a silica-terraced PLC platform, and the PD carriers with a $45^{\circ}$ mirror on which pin-PDs were bonded were assembled with the platform. A clear transmitter eye-pattern and minimum receiver sensitivity of -24.5 dBm were obtained under 1.25 Gb/s operation for digital applications, and a second-order inter-modulation distortion (IMD2) of -70 dBc was achieved for an analog receiver.

• ETRI Journal
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• v.38 no.5
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• pp.981-987
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• 2016

We present a cost-effective dual polarization quadrature phase-shift coherent receiver module using a silica planar lightwave circuit (PLC) hybrid assembly. Two polarization beam splitters and two $90^{\circ}$ optical hybrids are monolithically integrated in one silica PLC chip with an index contrast of $2%-{\Delta}$. Two four-channel spot-size converter integrated waveguide-photodetector (PD) arrays are bonded on PD carriers for transverse-electric/transverse-magnetic polarization, and butt-coupled to a polished facet of the PLC using a simple chip-to-chip bonding method. Instead of a ceramic sub-mount, a low-cost printed circuit board is applied in the module. A stepped CuW block is used to dissipate the heat generated from trans-impedance amplifiers and to vertically align RF transmission lines. The fabricated coherent receiver shows a 3-dB bandwidth of 26 GHz and a common mode rejection ratio of 16 dB at 22 GHz for a local oscillator optical input. A bit error rate of $8.3{\times}10^{-11}$ is achieved at a 112-Gbps back-to-back transmission with off-line digital signal processing.

• ETRI Journal
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• v.25 no.2
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• pp.73-80
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• 2003

This paper describes an effective method for forming silicon oxide on silica-on-silicon platforms, which results in excellent characteristics for hybrid integration. Among the many processes involved in fabricating silica-on-silicon platforms with planar lightwave circuits (PLCs), the process for forming silicon oxide on an etched silicon substrate is very important for obtaining transparent silica film because it determines the compatibility at the interface between the silicon and the silica film. To investigate the effects of the formation process of the silicon oxide on the characteristics of the silica PLC platform, we compared two silicon oxide formation processes: thermal oxidation and plasma-enhanced chemical vapor deposition (PECVD). Thermal oxidation in fabricating silica platforms generates defects and a cristobalite crystal phase, which results in deterioration of the optical waveguide characteristics. On the other hand, a silica platform with the silicon oxide layer deposited by PECVD has a transparent planar optical waveguide because the crystal growth of the silica has been suppressed. We confirm that the PECVD method is an effective process for silicon oxide formation for a silica platform with excellent characteristics.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.53-65
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• 1998

Planar lightwave circuits (PLCs) provide various important devices for optical wavelength division multiplexing (WDM) systems, subscriber networks and etc. This paper reviews the recent progress and future prospects of PLC technologies including arrayed-waveguide grating multiplexers, optical add/drop multiplexers, programmable dispersion equalizers and hybrid optoelectronics integration technologies.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.265-266
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• 2008

The environmental and mechanical reliability of planar lightwave circuit (PLC)-type optical splitter modules is investigated with references [1, 3]. The module is composed of Y-branching silica-based waveguides on Si connected to optical fiber with UV-curable adhesives and is packaged in a metal case which is filled with humidity-resistant resin. High optical performance such as low loss, low reflection, and thermal stability are obtained through the use of this fiber connection technique. Ten reliability tests including long-term environmental and mechanical and ALT test were carried out for more then ten $1{\times}32$ channel PLC splitter modules.

• ETRI Journal
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• v.24 no.5
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• pp.398-400
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• 2002

Using $Cr_2O_3$ thin film, we developed a novel etch-stop technique for the protection of silicon surface morphology during deep ion coupled plasma etching of silica layers. With this technique we were able to etch a silica trench with a depth of over 20 ${\mu}m$ without any damage to the exposed silicon terrace surface. This technique should be well applicable to fabricating silica planar lightwave circuit platforms for opto-electronic hybrid integration.

• Proceedings of the Optical Society of Korea Conference
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• 1998.08a
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• pp.152-153
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• 1998

PLC 기술을 이용하여 16 채널 실리카 AWG 모듈을 제작하여 특성을 측정하였다. 입출력 광섬유간의 삽입손신은 3.77~6.55dB, 옆 채널간 crosstalk는 19dB, 채널 사이의 파장 간격은 0.8$\pm$0.02nm으로 측정되엇다. 온습도 주기 시험을 통하여 모듈의 신뢰성을 검증하였다.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.589-593
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• 2003

Silica based Planar Lightwave Circuits (PLC) have been applied to various kinds of wave-guided optical passive devices. SiO$_2$ (buffer) and GeO$_2$-SiO$_2$ (core) thick films have been deposited by Flame Hydrolysis Deposition (FHD). The SiO$_2$ films were produced by the flame hydrolysis reaction of halide materials such as SiCl$_4$, POCl$_3$ and BCl$_3$ into an oxy-hydrogen torch. The P concentration increased from 2.0 to 2.8 at％ on increasing the POCl$_3$/BCl$_3$ flow ratio. The refractive index increased from 1.4584 to 1.4605 on increasing the POC1$_3$/BC1$_3$ flow ratio from 0.6 to 2.6. The refractive index of GeO$_2$-SiO$_2$ films was controlled by the GeCl$_4$ flow rate. The refractive index increased from 1.4615 to 1.4809 on increasing the GeCl$_4$ flow rate from 30 to 120 sccm.