• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.1044-1045
• /
• 2005

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.1030-1031
• /
• 2005

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.875-876
• /
• 2005

• Journal of the Optical Society of Korea
• /
• v.9 no.3
• /
• pp.87-91
• /
• 2005

The strontium magneto optical trap followed by a Zeeman slower has been demonstrated. The isotope selective characteristics of the trap have been investigated. The fluorescence spectrum of the MOT was compared with those of other high resolution spectroscopic methods. The red detuned deflection beam is also considered for a more selective spectrum.

• Advances in nano research
• /
• v.1 no.3
• /
• pp.153-158
• /
• 2013

An approach to achieving of spatially homogeneous, ordered ensemble of semiconductor quantum rods in polymer film of polyvinyl butyral is reported. The CdSe/ZnS quantum rods are embedded to the polymer film. Obtained film is stretched up to four times to its initial length. A concentration of quantum rods in the samples is around $2{\times}10^{-5}$ M. The absorption spectra, obtained in the light with orthogonal polarization, confirm the occurrence of spatial ordering in a quantum rod ensemble. Anisotropy of the optical properties in the ordered quantum rod ensemble is examined. The presented method can be used as a low-cost solution for preparing the nanostructured materials with anisotropic properties and high concentration of nanocrystals.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2004.10a
• /
• pp.695-696
• /
• 2004

• Journal of the Optical Society of Korea
• /
• v.7 no.3
• /
• pp.139-144
• /
• 2003

We have characterized the optical parametric chirped-pulse amplification of femtosecond Ti:sapphire laser pulses by using a BBO crystal. It is numerically verified that a high gain and a broad gain bandwidth can be obtained with a 532-nm pump laser. The dependence of the gain profile of OPA on phase matching angles, pump intensity, and crystal length is numerically investigated. Experimental results shows that the temporal fluctuation of a pump laser causes the modulation of an amplified spectrum in OPCPA.

• Journal of the Optical Society of Korea
• /
• v.16 no.1
• /
• pp.53-56
• /
• 2012

We have developed a slab-type Nd:YAG gain module based on the techniques of conduction cooling and end pumping. The Nd:YAG slab is end-capped on both ends by undoped pure YAG and is pumped through the end-caps by stacked arrays of laser diode bars. The slab's surfaces of total internal reflection are in contact on both sides with microchannel cooling blocks which are cooled by water circulation. The power oscillator based on the gain module generates more than 400 W at 1-kW pumping with a slope efficiency of 55%. The small-signal gain of the gain module is 10 in a single zig-zag pass, and the amplified beam shows a near diffraction-limited beam quality.

• Korean Journal of Optics and Photonics
• /
• v.16 no.2
• /
• pp.159-161
• /
• 2005

We report the selective area bandgap tuning of multiple quantum well structures by an impurity free vacancy induced quantum well intermixing technique. A 3dB waveguide directional coupler was fabricated in the disordered section of an intermixed quantum well sample as a demonstration of photonic device applications.

• Journal of the Optical Society of Korea
• /
• v.7 no.3
• /
• pp.193-196
• /
• 2003

We have developed a laser welding monitoring system to monitor laser welding process conditions such as sample feed rate, laser focal position, and laser power. A 2 ㎾ Nd:YAG CW laser beam has been applied to the welding of a stainless steel plate (SUS306) to investigate the welding monitoring. Theradiation signal from the weld pool was guided back through the focusing optics and the laser delivery fiber, and measured by a photo detector. By changing the focus of the laser beam along the z-direction, the penetration depth of the welding material has been measured. That shows the penetration depth depends on the frequency fluctuations of the plume signals which can be used in welding quality control.