• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.12 s.91
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• pp.1207-1215
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• 2004

A Gigabit Ethernet upstream transmission over a WDM-PON employing remotely wavelength-locked Fabry-Perot lasers has been demonstrated. We have successfully demonstrated a WDM transmission of four Gigabit Ethernet channels with 100 GHz channel spacing over 30 km conventional single mode fiber. The measured f-factor was larger than 17.1 dB. We have also investigated the beating noise characteristics of a wavelength-locked Fabry-Perot laser and showed the remotely wavelength-locked Fabry-Perot laser suppresses the intensity noise of the incoherent light injected, which cause a 6.3 dB SNR improvement compared with that of the conventional spectrum-sliced light source.

• Journal of the Optical Society of Korea
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• v.17 no.2
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• pp.117-129
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• 2013

We briefly review the recent progress in passively mode-locked fiber lasers (PMLFLs) based on semiconductor saturable absorber mirrors (SESAMs) and discuss the detailed characterization of a SESAM-based, passively mode-locked erbium-doped fiber (EDF) laser operating in the 1.5-${\mu}m$ spectral range for various configurations. A simple and compact design of the laser cavity enables the PMLFL to generate either femtosecond or wavelength-tunable picosecond pulses with high stability as the intra-cavity filtering method is altered. All the cavities investigated in our experiments present self-starting, continuous-wave mode-locking with no Q-switching instabilities. The excellent stability of the source eventually enables the wavelength-tunable PMLFL to be used as a master oscillator for a power-amplifier source based on a large-core EDF, generating picosecond pulses of >10-kW peak power and >100-nJ pulse energy.

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.201-210
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• 2001

Wavelength and repetition-rate tunable optical pulse-trains for ultrafast optical time- and wavelength division multiplexing are generated from a semiconductor fiber ring laser by optical injection mode-locking. The pulse trains show the pulse with of ${\sim}10$ ps and the wavelength tuning of wider than 30 nm at various repetition-rates of 10 GHz, 20 GHz, 30 GHz and 40 GHz, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9A
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• pp.704-711
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• 2009

In this paper, we report the results of the field trial test of 1GbpsX16channels Injection locking FP-LD based WDM-PON system which could guarantee 40Mbps minimum bandwidth per subscriber, We have confirmed the system reliability, also verified that the system could reliably deliver the service such as internet, VoD through the systems during the field trial test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.1009-1011
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• 2012

In this paper, a wavelength tunable light source based on mutually injected locking with two F-P LDs, has been constructed and then analyzed for wavelength shift and RIN (Relative Intensity noise) according to temperature. We have measured maximum about 2 nm for the wavelength shift and minimum -110dB/hz for the RIN. Also, the RIN and beating noise in eye patterns are increased by changing temperature high.

• Korean Journal of Optics and Photonics
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• v.23 no.5
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• pp.211-216
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• 2012

We report a resonance fiber Bragg sensor interrogation based on a Fourier domain mode-locking (FDML) laser. The FDML laser is constructed based on a conventional ring laser cavity configuration with fiber Fabry-Perot tunable filter (FFP-TF). There are two sensor parts which are composed with two FBGs inside the laser cavity. Each sensor part provides a separate laser cavity for the FDML laser. The resonance frequencies of the laser cavities are 46.687 kHz and 44.340 kHz, respectively. We applied a static and a dynamic strain on the FBG sensor system. The slope coefficients of the measured relative wavelength shift and relative time interval from the static strain are found to be $0.61pm/{\mu}{\epsilon}$ and $0.8ns/{\mu}{\epsilon}$, respectively.

• Korean Journal of Optics and Photonics
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• v.17 no.3
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• pp.268-272
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• 2006

We have demonstrated the selection and the amplification of the components of an optical frequency comb using femto-second laser injection-locking technique. We used a mode-locked Ti:sapphire laser as a master laser and a single-mode diode laser as a slave laser. After passing through the interference filter with the center wavelength 794.7 nm and the transmittance bandwidth 1.5 nm, the optical frequency comb by mode-locked femto-second laser was injected into the slave laser. The injection-locked slave laser had $3{\sim}4$ multi-mode with the mode spacing 100.5 MHz, whichcorrespond to the repetition rate of a mode-locked Ti:sapphire laser. The power of the modes selected by femto-second laser injection-locking technique was amplified to several thousands times

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.123-123
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• 2013

OCT (Optical Coherence Tomography)는 의료용 생체조직의 단층 영상을 레이저 빛을 이용하여 구현하는 첨단 의료기술이다. Time-domain과 Fourier-domain을 기반으로 다양한 광간섭 신호의 획득이 연구되고 있으며, 영상획득 속도의 향상을 위한 경쟁이 세계적으로 치열한 상황이다. 최근 초고속 파장훑음 광원(Wavelength-swept source)의 개발을 통하여 초당 300 frame 이상의 단층 영상이 구현되고 있다. 본 발표에서는 초고속 파장훑음 레이저 광원(Wavelength swept laser)이 능동형 모드잠금(Active mode locking) 외부공진 반도체 공진 구조를 기반으로 새롭게 구현된 연구 성과를 포함한다. 분산에 의한 모드 잠금에 의하여 발진 파장이 결정되어 가변하므로 1 MHz 급 이상의 초고속 반복이 가능하며, 특히 의료용 산업용 분야의 다양한 광센서 및 광영상 응용에 활발히 응용되고 있다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.74-77
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• 2006

A scanned Fabry-Perot(F-P) filter and a Multi-Channel Wavelength Locker(MCWL) were used to interrogate fiber Bragg grating sensor array. When the F-P filter scans over the MCWL which works as a multi-reference the temporal peaks profiles correspond to the locking wavelengths. To solve the linearity, stability, and accuracy problems caused by the nonlinear response of F-P filter, a polynomial fitting algerian was used to calculate the relationship between the peak locations and the wavelengths in all the scanning range. Then from the reflected peaks locations and the best fitting line, the Bragg wavelengths can be obtained. The measurement linearity was greatly enhanced with wavelength resolution of about 4 pm in 10Hz scanning frequency.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.104-109
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• 2021

In this paper, we experimentally demonstrate a self-seeding FP-LD (Fabry Perot Laser Diode) to verify the possibility of a new tunable light source that can be used in WDM-PON (Wavelength Division Multiplexing - Passive Optical Network) system. The conventional implementation of WDM-PON using a tunable light source has a disadvantage that the center wavelength of the AWG (Arrayed Waveguide Grating) device and the tunable light source must be precisely aligned. However, the proposed tunable light source has the advantage that the tunable wavelength is automatically aligned with the center wavelength of the AWG as well as simple structure. The implemented tunable light source had a tunable band of about 14 nm or more, and the maximum RIN (Relative Intensity Noise) of about -124 dB/Hz, which showed the possibility of modulating 10 Gb/s signal by an external modulator.