• 전기전자학회논문지
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• 제18권1호
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• pp.19-24
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• 2014

We report stable, wideband, flat-topped, 10 GHz optical frequency comb generation from a semiconductor-based mode-locked ring laser with an intra-cavity high finesse Fabry-Perot etalon. We demonstrate a stable 10 GHz comb with greater than 200 lines within a spectral power variation below 1 dB, which is the largest value obtained from a similar mode-locked laser in our knowledge. Greater than 20 dB of the spectral peak to deep ratio at 0.02 nm resolution, ~92 femtosecond timing jitter over 1 kHz to 1 MHz range, and non-averaged time traces of pulses confirm very stable optical frequency comb lines.

• Journal of the Optical Society of Korea
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• 제4권1호
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• pp.11-13
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• 2000

We experimentally measured the cold cavity loss of a mode-locked erbium-doped fiber ring laser in situ by using the relaxation oscillation frequency method. The relaxation oscillation frequency is measured for various pumping powers and the data is fitted by the least squares method with a theoretical curve of parameters including the cavity loss. We obtained a cavity loss of 15.3$\pm$0.5 dB which was found to agree with the results of direct transmission loss measurements.

• Journal of the Optical Society of Korea
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• 제14권1호
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• pp.14-21
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• 2010

Fiber ring laser based intra-cavity absorption spectroscopic sensor has great potential for high sensitivity gas detection. Using the rate equations and propagation equations, we investigated theoretically factors that affect the sensitivity of such fiber ring laser sensors and determined the optimal design parameters and conditions for significant enhancement of the system sensitivity. Experiments have been conducted to determine the sensitivity enhancement performance. The results showed a factor of 25 ~ 30 in sensitivity enhancement in the experimental system, agreeing well with the theoretical expectations. Experiments on acetylene detection have also been carried out and the results showed that the ring cavity significantly increases the signal absorption and that high sensitivity can be obtained for gas detection.

• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 제16회 정기총회 및 동계학술발표회
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• pp.14-15
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• 2005

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 제13회 정기총회 및 2002년도 동계학술발표회
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• pp.70-71
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• 2002

• Journal of the Optical Society of Korea
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• 제17권2호
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• pp.177-181
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• 2013

We present an all-fiberized power-scalable, sub-nanosecond mode-locked laser based on a frequency-shifted-feedback ring cavity comprised of an erbium-doped fiber, a downshifting acousto-optic modulator (AOM), and a bandpass filter (BPF). With the aid of the frequency-shifted feedback mechanism provided by the AOM and the narrow filter bandwidth of 0.45 nm, we generate self-starting, mode-locked optical pulses with a spectral bandwidth of ~0.098 nm and a pulsewidth of 432 to 536 ps. In particular, the output power is readily scalable with pump power while keeping the temporal shape and spectral bandwidth. This is obtained via the consolidation of bound pulse modes circulating at the fundamental repetition rate of the cavity. In fact, the consolidated pulses form a single-entity envelope of asymmetric Gaussian shape where no discrete internal pulses are perceived. This result highlights that the inclusion of the narrow BPF into the cavity is crucial to achieving the consolidated pulses.

• 한국광학회지
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• 제20권6호
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• pp.339-345
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• 2009

결정을 이용하여 고출력 단일모드 특성을 가지는 수직공진 표면발광 레이저를 제작하고 발진 특성을 관찰하였다. 일반적으로 광 밴드갭 형성을 위해 수십개의 광 결정 홀을 식각하나, 이번 연구에서는 6개의 홀만으로 단일모드를 구현하였고, 폴리이미드로 홀을 메우게 되어 신뢰성이 유리한 장점이 있다. 산화 구경과 광 결정 홀의 크기를 변화시키며 실험을 진행하여 단일모드 특성의 변화를 분석하였다. 다양한 광 결정 구조를 가진 수직공진 표면발광 레이저에서 고출력 단일모드 발진이 가능함을 확인하였다.

• 한국광학회지
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• 제16권5호
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• pp.406-410
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• 2005

처프된 광섬유 브라그 격자를 사용하여 발진모드 수를 조절할 수 있는 외부 공진기 레이저를 제안하였다. 광섬유 브라그 격자에 인가되는 선형적인 온도차를 변화시킴으로써 광섬유 브라그 격자의 반사 대역폭을 조절할 수 있었으며 이러한 격자를 외부 공진기 레이저의 외부 반사경으로 사용하여 발진모드 수를 단일모드에서 세 개의 모드까지 조절할 수 있었다.

• 한국광학회:학술대회논문집
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• 한국광학회 1998년도 제15회 광학 및 양자전자 학술발표회 논문집
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• pp.198-199
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• 1998

• 광학세계
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• 제14권4호통권80호
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• pp.71-73
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• 2002