Center for Molecular Spectroscopy and Dynamics

2016 ABC

In biomedical imaging, the microendoscope is essential for minimally-invasive imaging. But it is inevitable that there is back-reflected noise from the surface of the probe at the epi-illumination endoscopic system. In this study, we proposed the method for reducing the back-reflected noise and combined it with our transmission matrix method to obtain a high-resolution image. We used an image bundle fiber as a probe which is very suitable for microendoscope. But if the light is coupled into fiber’s full area for sample illumination, then the back-reflected noise and the sample signal are delivered together through every single core and it spoils the image quality. To overcome this problem, we focused the beam into each core of the bundle fiber and detected the full area of the fiber. We could measure the bundle fiber image with noise-free signal with an illumination spot and this spot was easy to remove in our imaging process. Applying transmission matrix method, we obtained a high-resolution and pixelation-free image. We demonstrated that core focusing-illumination method enhanced the image contrast compared to wide-field illumination especially in the case of the sample with lower contrast. Our approach will improve the performance of the microendoscopic imaging in biomedical applications.