Abstract
In this study, we established an en-face scanning system by integrating an optical coherence tomography (OCT) and a telescope-based scanning system. Using the characteristic of developed OCT, a low coherent light source, together with the coherent gate and a telescope-based scanning system, two-dimension coherent image can be identified. The design of telescope-based scanning system could be also verified by mathematical matrix deduction. As for the system performance, we applied 130 mA electrical current to drive superluminant diode (SLD) such that the axial resolution could reach to 8.50 μm. In addition, in an effort to estimate the precision of stepping motor the corresponding spot image for each step is captured using CCD; therefore, the precision with each step, that is, the distance between two consecutive spots, could be obtained using two-dimensional cross-correlation process. In the precision of stepping motor experiment that setting 1 μm per step, the error can be kept 0.02 μm. Similarly, the process could be also applied to estimate the transversal resolution of the scanning system. We found that it requires 0.6 mV to drive the scanning mirror so that 5 μm displacement at the focal plane of the objective could be obtained. Furthermore, while measuring the oil with different refractive index, the result shows that the visibility of refractive index difference that can be identified is 0.07. Presently, our instrument can accomplish two-dimensional image scan but it can’t be distinguished by the coherence gate.