| Title |
A Study on Optical Coherence Tomography System by Using the Optical Fiber |
| Authors |
Sung-Kuk Yang ; Yang-Ha Park ; Won-Seak Jang ; Sang-Ki Oh ; Seok-Jeong Lee ; Ki-Moon Kim |
| Keywords |
Optical Coherence Tomography ; SLD ; Michelson interferometer ; Interference |
| Abstract |
In this paper, we have studied the OCT(Optical Coherence Tomography) system which has been advantages of high resolution, 2-D cross-sectional images, low cost and small size configuration. The characteristics of light source determine the resolution and coherence length. The light source has a commercial SLD with a central wavelength of 1,285 nm, 35.3 nm(FWHM). The optical delay line is necessary to make equal with the optical path length to scattered light or reflected light from a sample. In order to make equal the optical path length, the stage that is attached to a reference mirror is controled by a step motor. And the interferometer is configured with the Michelson interferometer by using a single mode fiber, and the scanner can be focused on the sample by using a reference arm. Also, the 2-dimension cross-sectional images were measured with scanning the transverse direction of the sample by using a step motor. After detecting the internal signal of lateral direction, a scanner is moved to obtain the cross-sectional image of 2-dimension by using step motor. A photodiode, which has high detection sensitivity and excellent noise characteristics has been used. The detected small signal has a noise and interference. After filtering and amplifying the signal, the output signal is demodulated the waveform. And then, a cross-sectional image is seen through converting this signal into a digitalized signal by using an A/D converter. The resolution of the sample is about 30㎛, which corresponds to the theoretical resolution. Also, the cross-sectional images of onion cells were measured in real time scheme. |