• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.334-340
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• 2008

We investigated the electromagnetically induced transparency (EIT) and the Hanle spectrum in a paraffin coated Rb vapor cell. The EIT spectrum was observed in the $F_g=2$, $3{\rightarrow}F_e=3$ transition of the $^{85}Rb$ $D_1$-line by using two independent external cavity diode lasers, and the Hanle spectrum was observed by using one external cavity diode laser in the $\Lambda$-type scheme between the Zeeman sublevels of the $F_g=2{\rightarrow}F_e=1$ transition of the $^{87}Rb$ $D_1$-line. In the Hanle spectrum, we could observe the dual-structured spectrum in the paraffin coated vapor cell. We investigated the dual-structured lineshape by applying an external magnetic field, and varying the direction of the magnetic field. The narrow linewidth of dual-structured EIT was measured to be approximately 200 Hz.

• Korean Journal of Optics and Photonics
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• v.17 no.2
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• pp.143-148
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• 2006

A new method of measuring the Brillouin gain spectrum of optical fiber is proposed and demonstrated. Unlike existing methods, both the pump light and the counter-propagating probe light are generated from a single laser diode whose optical frequency is directly modulated by injection current modulation. The frequency difference between the pump and the probe is scanned continuously through optical frequency chirp occurring when the injection current is modulated with a square wave. The measured Brillouin gain spectrum of telecom single-mode fiber agrees well with that shown in other literature.

• Korean Journal of Optics and Photonics
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• v.12 no.2
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• pp.115-120
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• 2001

In the present study, we described in detail a precise correction method of the copper emission spectra obtained from a highpressure and high-temperature pulsed plasma-jet. The pulsed plasma-jet is initiated from an electro-thermal capillary discharge through a small orifice, and expanded rapidly into an atmosphere. In order to characterize the plasma, fundamental measurements such as the plasma excitation temperature or electron number density are essential. However those spectral lines which are directly related to the excitation temperature or electron number density may be distorted by the spectral response of the optical instruments used. Therefore, in this paper, we discuss some efforts to derive precise correction methods of the copper emission spectra obtained from the pulsed plasma-jet. a-jet.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.304-309
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• 2015

To evaluate the degree of contamination caused by oil spill accident in the sea, the in-situ sensors which are based on the scientific method are needed in the real site. The sensors which are based on the fluorescence detection theory can provide the useful data, such as the concentration of oil. However these kinds of sensors commonly are composed of the ultraviolet (UV) light source such as UV mercury lamp, the multiple excitation/emission filters and the optical sensor which is mainly photomultiplier tube (PMT) type. Therefore, the size of the total sensing platform is large not suitable to be handled in the oil spill field and also the total price of it is extremely expensive. To overcome these drawbacks, we designed the fluorimeter for the oil spill detection which has compact size and cost effectiveness. Before the detail design process, we conducted the experiments to measure the excitation and emission spectrum of oils using five different kinds of crude oils and three different kinds of processed oils. And the fluorescence spectrometer were used to analyze the excitation and emission spectrum of oil samples. We have compared the spectrum results and drawn the each common spectrum regions of excitation and emission. In the experiments, we can see that the average gap between maximum excitation and emission peak wavelengths is near 50 nm for the every case. In the experiment which were fixed by the excitation wavelength of 365 nm and 405 nm, we can find out that the intensity of emission was weaker than that of 280 nm and 325 nm. So, if the light sources having the wavelength of 365 nm or 405 nm are used in the design process of fluorimeter, the optical sensor needs to have the sensitivity which can cover the weak light intensity. Through the results which were derived by the experiment, we can define the important factors which can be useful to select the effective wavelengths of light source, photo detector and filters.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.359-360
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.423-424
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.123-124
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.171-172
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.26-28
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• 1990

Cw arc 램프로 펌핑하는 Alexandrite 레이저의 형광을 optical Spectrum Analyzer를 이용하여 측정하였다. Vibronic 천이에 해당하는 광대역 형광 스펙트럼이 관측되었고, arc 램프 입력에 따른 peak 형광의 세기 및 peak intensity 파장의 입력 power 의존성을 조사하였다. 형광의 세기는 입력 power에 따라 0.16 /kw의 비율로 증가하였고, peak intensity 파장은 입력 power가 5kw 까지는 5 nm/kw 비율로 장파장쪽으로 이동하였다.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.199-203
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• 1990

원자와 강력한 빛이 상호작용을 하면 섭동이론으로 취급되지 않는 형광선들이 나타나게 된다. Nd:YAG 레이저로 펌핑된 색소레이저를 열 파이프 오븐에 발생시킨 Na 원자 기체의 D1 및 D2 흡수선에 입사시켜 Na 원자를 공명여기 시켰다. 그결과 빛 싸인 원자 모델에서 예측한 7개의 형광선을 얻었고 이들 형광선에 대한 입사광의 세기 및 detuning에 의한 효과에 대해 논의 검토하였다.