An OCT system with a swept light source centered around 1.7 μm for identifying atherosclerotic plaque and visualization of large lipid pool is provided. Advantages for using the 1.7 μm swept source laser include higher contrast between lipid and normal tissue and deeper penetration of the optical signals from the 1.7 μm swept source laser into the tissue. With deeper penetration into the tissue, more structural information from deep within the tissue is obtained. The present invention also features multimodality imaging systems that integrate additional imaging systems into the OCT system at 1.7 μm. As an example, an integrated 1.3 μm and 1.7 μm OCT system is provided which simultaneously generates OCT images using both the OCT systems which are used to characterize and differentiate the types of tissue.
