Ultrahigh resolution optical coherence tomography with femtosecond Ti:sapphire laser and photonic crystal fiber

Optical coherence tomography (OCT) with ultrahigh axial resolution was achieved by the super-continuum generated by coupling femtosecond pulses from a commercial Ti: sapphire laser into an air-silica microstructure fiber. The visible spectrum of the super-continuum from 450 to 700 nm centered at 540 nm can be generated. A free-space axial OCT resolution of 0.64 μm was achieved. The sensitivity of OCT system was 108 dB with incident light power 3 mW at sample, only 7dB below the theoretical limit. Subcellular OCT imaging was also demonstrated, showing great potential for biomedical application. Supported by the National Basic Research Program of China (Grant No. 001CB510307), Hi-tech Research and Development Program of China (Grant No. 2006AA02Z472), National Natural Science Foundation of China (Grant Nos 90508001, 10574081), and the Ministry of Education of China (Grant No. 306020)