• ETRI Journal
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• v.29 no.6
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• pp.838-840
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• 2007

The relation between the allowed range of variation of polarization controller wave-plates angles and the respective polarization scattering properties is investigated. It is demonstrated that a nearly uniform polarization scattering over the Poincare sphere is obtained using a concatenation of three polarization controllers with angles randomly changed between $-{\pi}$/4 and ${\pi}$/4. It is also shown that an improvement of the scattering properties is obtained if the configuration angles are allowed to change between $-{\pi}$/2 and ${\pi}$/2.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.171-180
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• 1998

The low cost fiber ring laser can be tuned by controlling polarization states within the loop. In this paper, we investigate its operating principle and verify the performance through an experiment. This ring laser consists of a polarization controller and an intracavity polarizer for the wavelength tuner and semiconductor optical amplifier for the gain medium. It is seen that the lasing wavelength may be tuned through the range of 1540~1560 nm as a polarization controller and a polarizer are adjusted.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.47-57
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• 2002

In this paper, a wavelength converter for RZ data which can controls XPM in SOA by using polarization controller within optical fiber loop mirror is proposed and demonstrated. The proposed structure needs only one polarization dependent SOA for implementation compared to previous XPM ones and makes the cost down. And it provides wavelength converted signals with non-inverted and inverted pattern into outputs respectively.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.47-48
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• 2003

A polarization mode dispersion(PMD) compensator with a reponse time less than 200ms has been developed. In our PMD compensator, a reset-free $LiNbO_3$ polarization controller was used in order to reduce the response time, and the compensation algorithm was based on maximization of degree of polarizaiton(DOP).

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.465-470
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• 2002

A novel phased array antenna system for space-borne polarimetric SAR is proposed and completed in this paper.The antenna system assures polarimetric and multi-mode capability of SAR. It has broadband, high polarization isolation and high port to port isolation. The antenna system is composed of broadband polarimetric microstrip antenna, T/R modules and multifunction beam controller nit. The polarimetric microstrip antenna has more than 100MHz bandwidth at L-band with -30dB polarization isolation and high port to port isolation. The microstrip element and T/R module's structure and characteristics, the subarray's performances measuring results are presented in detail in this paper. A design scheme on beam controller of the phased array antenna is also proposed and completed, which is based on Digital Signal Processing (DSP) chip -TMS320F206. This beam controller unit has small size and high reliability compared with general beam controller. In addition, the multifunction beam controller unit can acquire and then send the T/R module's working states to detection system in real time.

• Korean Journal of Optics and Photonics
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• v.8 no.1
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• pp.63-67
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• 1997

We have experimentally investigated the fiber four-wave mixing effect on equal spaced multichannel optical transmission system with dispersion shifted fiber. To reduce the fiber four-wave mixing effect, we set the polarization states of the adjacent channels to be orthogonal each other by using polarization controller. In this case, we can reduce the transmission power penalty by 1.5 dB compared with that of equal polarization states.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1534-1541
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• 2000

Wavelength tunable fiber ring laser can be tuned by causing a resonance on the optical path having the least loss which is controlled by a polarization adjustment. It is observed that lasing wavelengths having 1 nm FSR(Free Spectral Range) can be tuned over the range of 1540-1560 nm when a polarization controller and an intra-cavit polarizer with 1.5 mm air gap are adjusted. The characteristics of wavelength shift in the laser output are analyzed by introducing an optical path modeling and the concept of a birefringence loss.

• Korean Journal of Optics and Photonics
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• v.15 no.2
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• pp.142-148
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• 2004

We investigated a Ti:LiNbO$_3$ based integrated-optic polarization controller with a Ti-indiffused waveguide along the z-axis utilizing the electro-optic effect. The device consists of a first quarter-wave (λ/4) phase-shifter followed by a half-wave(λ/2) and a second quarter-wave(λ/4) wave-plate, which is rotated synchronously with the first quarter-wave phase-shifter. We analyzed the operation principles of the device utilizing cascaded transfer matrices based on Jones matrix and Poincare sphere, simulated driving voltages for various input states of polarization (SOP), and theoretically confirmed transformations from any arbitrary input SOP into any general output SOP.

• Korean Journal of Optics and Photonics
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• v.16 no.4
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• pp.376-383
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• 2005

We designed and fabricated integrated-optic tunable polarization controllers based on $LiNbO_3$ with the Ti-indiffused waveguide along the y-axis utilizing the electro-optic effect. The device consists of $TE↔TM$ mode converters and TE/TM phase shifters. We analyzed the operation principles of each device utilizing transfer matrices based on a Jones matrix and simulated shifting of the center wavelength by inducing voltage. We confirmed experimentally that the fabricated devices control the tunability of the center wavelength and the input SOP.

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.260-261
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• 2004