A device, system, and method for identifying an area of ablated tissue. Specifically, the device, system, and method may include a device having one or more fiber sensors and a processing unit for receiving emitted and/or reflected light from tissue and making one or more determinations based on the received light regarding ablated tissue, tissue contact, and/or occlusion. Each of the fiber sensors may include at least one multimode waveguide segment and at least one singlemode waveguide segment, or each of the fiber sensors may be singlemode waveguide. Further, each fiber sensor may have a core with long-period grating for optically coupling light from tissue to the fiber sensor. The processing unit may include a beam processing apparatus and a hyperspectral imaging and analysis apparatus, and may optionally include a light source.
