The effect of collimator lenses on the performance of an optical coherence tomography system

The effect of using collimator lenses with different focal lengths on the performance of a spectral-domain adaptive optics optical coherence tomography (AO-OCT) system has been studied. In vivo OCT scans of a healthy human retina were taken separately with different collimator lenses. Although shorter focal length lenses provide a smaller beam diameter at the pupil of the eye, and therefore a larger diffraction-limited spot size, on the return path the shorter focal length collimators demonstrate a better performance focusing the sinc-function-like intensity distribution returning from the eye on the fiber tip. The results might have applications in the OCT imaging of challenging cases.