• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.443-444
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 1991.07a
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• pp.67-70
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• 1991

종펌핑 Littman 공진기에서 선폭 500 MHz 이하의 단일 종모드 색소레이저를 발진켰으며, 에탈론 간섭무늬를 이용하여 단일종모드 색소레이저의 주파수를 안정화시켰다. 아울러 이들 레이저의 여러 특성을 조사하였으며, 최대효율은 2%, 문턱에너지는 130uJ이었다.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.94-95
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.254-255
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.110-111
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.437-438
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• 2006

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.3
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• pp.20-25
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• 1975

A microwave oscillator stabilized by a phase-locked loop (PLL) is developed. The PLL system is chosen 'compared with the cavity stabilized oscillator in view of the domestic manufacturing, because special machining and materials are needed for the latter. A sampler with a low pass filter is shown to be used as a phase detector in the PLL, and the sampler capable of sampling up to 4GHz is developed for this use. Frequency stability of about 10-6 is obtained from the developed microwave oscillator, operating at 2.16 GHz with more than 120 milliwatts output power, Ivhereby a crystal oscillator operating at about 110MHz is used as a reference source in the PLL. The capturing range of this oscillator is extended up to its lock-in-range of about 10MHz by employing a search oscillator in the system.

• Korean Journal of Optics and Photonics
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• v.15 no.3
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• pp.193-199
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• 2004

We present the double resonance optical pumping(DROP) spectra in the transition 5P$_{3}$2/-4D$_{3}$2/ and 5P$_{3}$2/-4D$_{5}$ 2/ of ($^{87}$ Rb) and the frequency stabilization in the $1.5mutextrm{m}$ region using those spectra. Those spectra have high signal-to-noise ratio and narrow spectral linewidth, which is about 10 MHz. We could account fur the relative intensities of the hyperfine states of those spectra by the spontaneous emission into the other state. When the frequency of the $1.5mutextrm{m}$ laser diode was stabilized to the DROP spectrum, the frequency fluctuation was about 0.2 MHz fDr sampling time of 0.1 s and the Allan deviation(or the square root of the Allan variance) was about 1${\times}$10$^{-11}$ for averaging time of l00s.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.386-387
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• 2011

본 논문은 플라즈마 방전장치 구동을 위한 가변 전압/주파수 전원장치를 제안한다. 제안하는 전원장치는 가변전압을 위한 벅-부스트 컨버터와 주파수 변환을 위한 푸쉬-풀 인버터로 구성된다. 제안하는 전원장치의 벅-부스트 컨버터는 계통전류 고조파 저감과 DC링크 캐패시터 최소화를 위하여 PFC(Power Factor Collection)기법을 적용한다. 그리고 푸쉬-풀 인버터는 출력 변압기의 자기포화를 막기 위해 전류제한기법을 추가한다. 또한 불분명한 부하와 출력 트랜스의 공진 상황에서 전압 안정화를 위해 출력전압을 피드백하여 제어한다. 본 논문은 1[kW]급 플라즈마 전원장치를 통하여 제안하는 토폴로지와 제어방법의 타당성을 검증한다.

• Korean Journal of Optics and Photonics
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• v.8 no.1
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• pp.26-30
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• 1997

A wide dynamic range heterodyne interferometer scheme using intermode beat between a stabilized, dual frequency He-Ne laser beam has been applied for a measurement of optical thickness of an optical medium. Resolution of the optical thickness measurement is about $\pm$ 1.74 ${\mu}{\textrm}{m}$. Using this technique, we are able to determine the optical thickness of an organic dye film. We also obtain a map of the optical thickness variations over a surface of the film