High resolution, spectroscopic optical coherence tomography in the 900 - 1100 nm wavelength range

Abstract

We demonstrate for the first time optical coherence tomography (OCT) in the 900-1100 nm wavelength range. A photonic crystal fiber (PCF) in combination with a sub-15fs Ti:sapphire laser is used to produce an emission spectrum with an optical bandwidth of 35 nm centered at ∼1070 nm. Coupling the light from the PCF based source to an optimized free space OCT system results in ∼15 μm axial resolution in air, corresponding to ∼10 μm in biological tissue. The near infrared wavelength range around 1100 nm is very attractive for high resolution ophthalmologic OCT imaging of the anterior and posterior eye segment with enhanced penetration. The emission spectrum of the PCF based light source can also be reshaped and tuned to cover the wavelength region around 950-970 nm, where water absorption has a local peak. Therefore, the OCT system described in this paper can also be used for spatially resolved water absorption measurements in non-transparent biological tissue. A preliminary qualitative spectroscopic OCT measurement in D<inf>2</inf>O and H<inf>2</inf>O phantoms is described in this paper. © 2002 SPIE · 1605-7422/02/$15.00.