• 전기학회논문지
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• 제56권6호
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• pp.1117-1121
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• 2007

We demonstrate a wavelength swept mode-locked ring laser for the frequency domain optical coherence tomography(FD OCT). A laser is constructed by using a semiconductor optical amplifier, fiber Fabry-Perot tunable filter and 2.6 km fiber ring cavity. Mode-locking is implemented by 2.6 km fiber ring cavity for matching the fundamental or harmonic of cavity roundtrip time to a sweep period. The wavelength sweeps are repetitively generated with the repetition period of 77.2 kHz which is the parallel resonance frequency of Fabry-Perot tunable filter for the low driving current consumption of the fiber Fabry-Perot tunable filter. The wavelength tuning range of the laser is more than FWHM of 61 nm centered at the wavelength of 1320 nm and the linewidth of the source is $0.014{\pm}0.002$ nm.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.227-231
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• 2011

An external optical modulation using absorption s in a Fabry-Perot laser diode (FP-LD), has been proposed and experimentally demonstrated for multicasting in a WDM-PON. The center wavelengths of absorption s in an FP-LD move to short-wavelength rapidly by only a small current (~1 mA) injection. If the current injection is stopped, the s move back to the original position. Such a movement of the s can make the FP-LD act as an external optical modulator, which is found to modulate at a maximum modulation speed of 800 Mbps or more. For a multicasting transmitter in a WDM-PON, the proposed modulator can be cost-effectively applied to a multi-wavelength laser source with the same periodicity of the longitudinal mode. Instead of the multi-wavelength laser source, tunable-LDs are used for experiments. The 32 channel multicasting system with the proposed modulator has been demonstrated, showing power penalties of 1.53~4.15 dB at a bit error rate of $10^{-9}$ with extinction ratios better than 14.5 dB at 622 Mbps.

• 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.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.174-179
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• 2003

Non-destructive test on the size and depth of cracks has been required for the safety evaluation of structures. Ultrasonic method based on laser techniques is one of the most popular non-destructive methods which overwhelm PZT based tests. In the present paper, ultrasonic was generated by high powered Q switching Nd:YAG pulse laser. Experiments were carried out using Fabry-Perot interferometer which was intensively discussed in the present study.

• 한국광학회지
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• 제23권1호
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• pp.42-51
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• 2012

본 논문에서는 패브리 페롯 레이저 다이오드(FP-LD : Fabry-Perot LD)에서 활성층 구조에 따른 주입 잠금 특성을 비교하였다. 편광 및 무편광 다중양자우물 구조와 무편광 벌크 구조의 이득 스펙트럼 및 주입 캐리어 밀도에 따른 최대 이득 특성을 TE, TM 편광에 대하여 계산하였다. 계산된 이득 파라미터를 시영역 대신호 모델에 적용하여 FP-LD의 주입 잠금 특성을 확인한 결과, 무편광 FP-LD가 편광 FP-LD 에 비하여 RIN(Relative Intensity Noise) 특성 면에서 약 3 dB 정도 우수하고, 2.5 Gbps 변조시에 아이 특성이 훨씬 우수함을 알 수 있다.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.698-703
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• 2016

We report a new all-optical flip-flop (AOFF) with a quite simple structure, using optical beating in an injection-locked Fabry-Perot laser diode (FP-LD) with optical bistability. While conventional AOFF methods using an injection-locked FP-LD require additional devices such as secondary FP-LDs or polarization controllers for reset operation, the proposed method can be implemented using only a single commercially available FP-LD with set and reset signals. The optical beating induces intensity fluctuations inside the FP-LD, and releases the locking state to the reset state. Even though we demonstrated the AOFF at 100 Mbit/s, we expect that its operation rate could extend to 10 Gbit/s, according to the limit of the FP-LD's frequency response.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.309-312
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• 2008

We study signal characteristics of the injection-locked Fabry-Perot laser diodes(FP-LDs) for the development of a costeffective WDM-PON solution. The output power and system performance of WDM-PON using injection locked FP-LD are depend on optical characteristics of injection source. The effect of optical power and polarization state of the injection source experimentally investigated. We also measured BER characteristics of the directly modulated FPLD and its power penalty at the BER of $10^{-9}$.

• Journal of the Optical Society of Korea
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• 제12권4호
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• pp.359-363
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• 2008

A novel WDM-PON system delivering bidirectional 1.25-Gbps data and broadcasting data is proposed. A subcarrier signal modulates optical carriers of a Fabry-Perot-laser-diode based broadband light source to broadcast to all users. Reflective semiconductor optical amplifiers are used as modulators for the baseband data at both the optical line terminal and the remote optical network unit for a channel. Bit error rate and error vector magnitude were measured to demonstrate the proposed scheme.

• 한국광학회지
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• 제8권6호
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• pp.466-470
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• 1997

광학 다층박막 증착법으로 비정질 $As_2S_3$를 중간층으로 하고 앞뒷면 거울의 반사율을 다르게 한 비대칭 Fabry-Perot 에탈론을 구성하고 광의 편광에 따른 광쌍안정 현상을 관찰하였다. 사용된 중간층의 광학적 두께는 광원인 $Ar^+$($\lambda $=514.5 nm) 레이저 광에 대하여 2$\lambda$가 되도록 하였다.$Ar^+$레이저의 출력이 80~100 mW일 때 광쌍안정 현상이 관측되었고, 입사되는 광의 각 편광상태에 따라 반사와 투과하는 광의 경향이 서로 다름을 알 수 있었으며, 이는 광의 편광에 따른 비대칭 Fabry-Perot 에탈론내에서의 위상차가 입사광의 세기에 따라 다르기 때문인 것으로 해석되어질 수 있다.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.34-35
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• 2004