• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.115-120
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• 1991

홑곁모양(Single Mode) 광섬유를 써서 조절되는 곬진 짝짓게를 제작해서 이를 이용해 광섬유 공진고리 간섭계를 구성하였다. 광원으로 He-Ne 레이저의 빛살(0.6328$mu extrm{m}$)를 간섭계의 팔(Arm)에 입사시키고, 광섬유 고리에는 삼각파를 함수 발생기로 P. Z. T를 써서 가할 때 출력 끝에서 나오는 빛살의 공진 특성 및 주파수 분포를 조사하였다. 또한, 빛살이 입사되는 광섬유 팔에 편극 조절기를 부착해서 편극 변화에 따른 공진 현상의 변화를 조사하였다.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1823-1825
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• 2001

고리형 반도체-광섬유 레이저 공진기 안에 높은 복굴절률을 가지고 있는 편광 유지 광섬유 루프 거울을 삽입하여 새로운 구조의 다파장 발진 시스템을 제안하고 구현하였다. 이득 매질인 반도체 광 증폭기의 특성으로 인해 실온에서 파장 간격이 1 nm 이내인 22 개의 파장의 빛을 발진시킬 수 있었다.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.245-247
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• 2009

본 연구에서는 광섬유 자이로(Fiber Optic Gyro)의 광학부 간섭계를 모사하고자 한다. 디지털 신호처리를 이용하여 광섬유 고리의 응답특성을 모사한다. 디지털 신호의 1bit 분해능으로 0.1deg/hr의 성능을 내는 광섬유 자이로를 모사하기엔 부족하다. 본 연구에서는 Random Noise를 활용하여 분해능을 높임으로써 광섬유 고리의 성능을 정확히 모사하고자 한다. 입력 레이트에 Random Noise를 실어줌으로써 1bit 분해능의 성능을 높일 수 있다. 1bit 사이의 값들이 랜덤노이즈로 인해 1bit 더해지거나 빼짐으로써 정확한 값을 갖을 수 있다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.20-20
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• 2001

광섬유고리에 편광제어를 통해 여러 광경로들에 대해서 손실을 조정함으로써 손실이 작은 광경로에서 발진하게 함으로써 발진 파장을 가변시킬 수 있는 편광제어 파장가변 고리형 광섬유레이저를 구현하였다. 내부 공진편광기를 사용하여 1㎚의 종모드간격으로 발진을 일으킬 수 있었고 편광제어기 및 내부공진편광기를 조절해서 1540㎚에서 1560㎚의 범위에서 파장가변을 시킬 수 있었다. 또한 실험적으로 나타난 발진특성을 광경로와 복굴절손실의 개념을 사용하여 발진출력 특성을 분석함으로써 발진파장을 가변시키는 메카니즘을 추정해 보았다. 여기서 복굴절손실이 같은 광경로들의 종모드들 사이에 보강간섭이 일어나 발진파장을 변화시킬 수 있음을 알 수 있었다.

• Korean Journal of Optics and Photonics
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• v.2 no.1
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• pp.20-25
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• 1991

Using evanescent field coupling between single ($LP_{01}$) and double ($LP_{01}, LP_{11}$) mode optical fiber, we selected LPII mode beam. With a $LP_{11}$ mode beam from a double mode fiber. we fabricated $LP_{11}$ mode fiber optic resonant ring interferometer, and assured that the guided mode is $LP_{11}$ mode from a radiation beam coming through the prism output coupler. When an external perturbation applied to the signal arm of the $LP_{11}$ fiber optic resonant ring interferometer, we examined the change of radiation mode coming from a prism output coupler and an end of optical fiber. Using two photodiode, LPn mode beam converted to voltage. This two output voltages is applied to X and Y terminal of oscilloscope to display circular motion on oscilloscope.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.174-184
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• 2001

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-cavity polarizer are adjusted. The tuning mechanism can be expected by analyzing the characteristics of the laser output using an optical path model and the concept of a birefringence loss. It is found that the constructive interference between longitudinal modes of different optical paths may cause wavelength tuning in the fiber ring laser.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.411-414
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• 2008

The study is about simulation of optical circuit for oneself performance evaluation of Fiber Optic Gyro(FOG) closed-loop controller board. The Fiber Optic Interferometer Simulator is used a digital signal processing for cosine response specificity output of fiber optic coil about input rate. Response specificity of the fiber optic coil is $Vo(t)=K3[1+\cos\{K1(Vm(t)-Vm(t-{\tau}))+K2\}]$. Also the Fiber Optic Interferometer Simulator is able to confirm a output value with K1, K2 and K3 input. The fiber Optic Interferometer Simulator is able to oneself performance evaluation without fiber optical circuit. Because, it is the very same cosine response specificity of real fiber optic coil about input rate.

• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.324-330
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• 1995

Stimulated Brillouin scattering theory is described in an optical fiber. Frequency change with an optical heterodyne method is analyzed between reference signal of a source and stimulated Brillouin scattering signal in an optical fiber. By coupling a source with a few axial modes and an optical fiber ring resonator, Brillouin scattering is studied with a spectrum analyzer. Using reference beating signal of a source, we have reduced the Brillouin beating frequency from 13 GHz range to below GHz. Experimentally, we can see the Brillouin beating frequency from 13 GHz range to below GHz with a dispersion shifted fiber (1.32 GHz), Ti-doped fiber (900 MHz) and single mode optical fiber (870 MHz). MHz).

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.330-337
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• 1993

Figure '8' type, passively-mode-locked erbium-doped-fiber ring laser was developed, incorporating a nonlinear loop mirror. Transmittance of the loop mirror was found to be dependent on the incident light intensity due to the non-reciprocal nonlinear phase shift, which enables the passive mode locking of the laser. Self-starting of stable mode locking was possible with only controlling the polarization controllers inside the cavity without any help of external perturbation or modulation. The mode-locked output pulse shape was discussed in relation with the transmission characteristics of nonlinear loop mirror.