Improvement of axial resolution for optical coherence tomography using a synthesized light source

We demonstrated that a synthesized light source (SLS) consisting of two low coherence light sources is capable of enhancing spatial resolution in optical coherence tomography (OCT). The axial resolution of OCT is given by the half of coherence length of the light source. We fabricated an SLS with a coherence length of 2.3 mum and the side lobe intensity of 29 % under the intensity ratio of LED 1: LED 2 = 1: 0.4 by combining two light sources, LED 1 with a central wavelength of 700 nm and spectral bandwidth of 100 rim, and LED 2 of 898 nm and 85 nm. The coherence length of 2.3 Eun is 56% of the shorter coherence length in two LED's, therefore the axial resolution is 1.2 mum.