Study on the Effective Focal Volume Change due to Light Intensity Using Fluorescence Correlation Spectroscopy

형광상관분광법을 이용한 광세기에 따른 유효 초점 부피 변화에 대한 연구

  • Received : 2013.03.14
  • Accepted : 2013.04.19
  • Published : 2013.04.25


Using fluorescence correlation spectroscopy, we analyzed the change of effective focal volume of a confocal system with light intensity. The fluorescence correlation spectroscopy system was home-built in accordance with the He-Ne laser with a wavelength of 632.8 nm, and two kinds of samples (AlexaFluor657 and Quantum dot655) suitable for the wavelength of the laser beam were used. For each sample, we analyzed and compared the correlation functions obtained while changing the intensity of the light source in a range of 1~50 ${\mu}W$. The result shows that the radius of the focal area increases linearly through the increase of particle number and diffusion time in response to an intensity change in weak light below 10 ${\mu}W$. In the higher intensity region (>10~15 ${\mu}W$), the increasing rate of particle number and diffusion time keep increasing but at a much slower rate. Through this result, it was also found that the radius increasing rate of the focal area was reduced however, the radius still increased slightly.


Supported by : 한국연구재단


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