• Korean Journal of Optics and Photonics
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• v.21 no.5
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• pp.185-189
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• 2010

We demonstrate a single-frequency wavelength tunable erbium-doped fiber (EDF) ring laser. We used an unpumped-EDF as a saturable-absorber in order to obtain a stable single-frequency with a narrow-linewidth single-polarization mode in the ring cavity. The lasing wavelength was controlled by using bending-induced strain, such as tension and compression strain corresponding to the bending direction, applied to the fiber gratings. The fiber laser exhibited an output power of -1.85 dBm at a wavelength of 1540.72 nm for a pumping power of ~400 mW. An extinction ratio was measured to be more than 60 dB. The proposed tunable fiber laser maintains nearly the same output power while its lasing wavelength is controlled over in a wavelength range of 5 nm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.55-60
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• 2008

Multi-wavelength Erbium-doped fiber(EDF) ring laser was developed by using a sampled fiber Bragg grating reflecting multiple wavelengths, which was formed by impressing periodical pressure on the outside of a fiber Bragg grating. The wavelength spacing was varied to 4.1nm, 1.41nm and 0.82nm, by pressing the grating with the pressure period $200{\mu}m$, $580{\mu}m$ and $1000{\mu}m$, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1257-1262
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• 2008

A long-distance remote sensing of temperature and current based on a fiber Bragg grating (FBG) is proposed and demonstrated. The thermal expanding effect of the epoxy and the Er-doped fiber ring laser (EFRL) are applied to the sensor system to enhance the temperature and current sensitivity. An EFRL with a 5 km-single-mode fiber and a FBG shows a high extinction ratio of more than 60 dB and a low power fluctuation of less than 1 dB. The metal wires are used to supply the current to the sensors. When the NOA65 puts on the FBG as a thermal expanding material, the temperature and current sensitivity of the lasing wavelength shift are about $30\;pm/^{\circ}C$ and 3pm/mA, respectively. The proposed sensing scheme is useful for measurement of current or temperature at a distant object of more than several km.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.7 s.337
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• pp.13-20
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• 2005

We propose an erbium-doped fiber ring laser whose multi-wavelength oscillation is tunable and switchable by tuning fiber bragg gratings. By applying axial pressure on the fiber bragg grating, the wavelength spacing of the proposed laser can be tuned continuously. And by adjusting a polarization controller(PC), the proposed laser can be switched among dual-, triple- and four-wavelength lasing operations.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.187-188
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.196-197
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• 2005