• Korean Journal of Optics and Photonics
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• v.19 no.3
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• pp.242-245
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• 2008

A four-channel selective microwave filter was demonstrated incorporating an optical resonator router, which is constructed by integrating a $1{\times}4$ space switch with an arrayed ring filters featuring different free spectral ranges. The center frequency of each channel was determined by the FSR of the corresponding ring resonator, and the four channels centered at 10 GHz, 16 GHz, 18 GHz and 20 GHz were individually selected to provide a bandpass filtering via the control voltage applied to the switched resonator.

• Korean Journal of Optics and Photonics
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• v.4 no.1
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• pp.108-113
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• 1993

In this paper, we study the photorefractive properties of Fe indiffused $LiNbO_3$ waveguides. Comparing the photorefractive properties of $Fe:LiNbO_3$ with those of $LiNbO_3$, we confirm the increase of the diffraction efficiency and the sensitivity by Fe doping. Also for the photorefractive properties of $Fe:LiNbO_3$ waveguides with different ambient gases, the diffaction efficiency and the sensitivity of $Fe:LiNbO_3$ indifused in pure argon gases are the highest and its decay time is the shortest. Therefore, it is recommended that pure argon gases be used in Fe indiffusion process for good optical switches with photorefractive effect.

• Journal of Software Assessment and Valuation
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• v.15 no.2
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• pp.67-72
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• 2019

The recent explosion of data traffic, including cloud services, coupled with the Internet penetration has led to a surge in the need for ultra-fast optical networks that can efficiently connect the data center's reconfiguable resources. In this paper, the algorithms for controlling switching cell operation in the optical switch connection structure are proposed, and the resulting performance is compared and analyzed through simulation. Performance analysis results showed that the algorithm proposed in this paper has improved the probability of successful multi-connection setup by about 3 to 7% compared to the existing algorithm.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.11
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• pp.15-21
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• 1999

The scalability of optical cross-connect nodes is analyzed based on the limiting factor of transmission performance. The limiting factors considered are ASE noise accumulation and gain saturation in the optical amplifiers, and crosstalk in both wavelength multiplexers/demultiplexers and optical switches. When the wavelength multiplexer/demultiplexers crosstalk is lower than 25dB, Power Penalty is below 1dB for the cascaded transmission of 10 nodes with 4 input/output ports. When 10Gbps signals are transmitted through nodes with 4 and 16 input/output Ports, performance degradation due to switch crosstalk is dominant compared to that due to ASE noise accumulation if the switch crosstalk is larger than 30dB and 45dB, respectively. For the single stage transmission of 10Gbps signal with 21dB fiber link loss, the maximum loss of optical cross-connect nodes must be under 34dB to achieve the BER of $10^{-12}$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.153-165
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• 1995

The design procedure of a GaAs/AlGaAs semiconductor matrix optical switch is presented for a simplified tree architecture in the viewpoint of optical loss. A low loss, 0.537 dB/cm, pin type substrate is designed by considering the loss due to imputity doping at 1.3 $\mu$m wavelength. The operating voltage and the device length of a reversed ${\Delta}{\beta}$ electro-optic directional coupler(EODC) swith which is a cross-point device of the 4${\times}$4 matrix optical switch and the bending loss of rib waveguide are caculated as functions of waveguide parameters and bending parameters. There is an optimum bending radius for some waveguide parameters. It is recommened that higher optical confinement conditions such as wide waveguide width and higher rib-height should be chosen for structural parameters of a low loss and a process insensitive 4${\times}$4 matris optical switch. A 4${\times}$4 optical matrix switch which has a 3 dB loss and a 12 volt operating voltage is designed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.12
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• pp.639-647
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• 2001

We present an integrated optical microswitch, composed of silicon waveguides, gold-coaled silicon micromirrors, and electrostatic contact actuators, for applications to the optical signal transceivers. For a low switching voltage, we modify the conventional curled electrode microactuator into a electrostatic microactuator with touch-down beams. We fabricate the silicon waveguides and the electrostatically actuated micromirrors using the ICP etching process of SOI wafers. We observe the single mode wave propagation through the silicon waveguide with the measured micromirror loss of $4.18\pm0.25dB$. We analyze major source of the micromirror loss, thereby presenting guidelines for low-loss micromirror designs. From the fabricated microswitch, we measure the switching voltage of 31.74V at the resonant frequency of 6.89kHz. Compared to the conventional microactuator, the present contact microactuator achieves 77.4% reduction of the switching voltage. We also discuss a feasible method to reduce the switching voltage to 10V level by using the electrode insulation layers having the residual stress less than 30MPa.