Optical feedback RF ablator and ablator tip

An ablation catheter comprising:

• an elongated catheter body extending longitudinally between a proximal end and a distal end along a longitudinal axis;
• at least one ablation element disposed in a distal portion which is adjacent the distal end of the catheter body to ablate a targeted tissue region outside the catheter body;
• an illumination or excitation optical element disposed in the distal portion, the illumination optical element being light-transmissive to emit light from the illumination optical element to the targeted tissue region;
• a collection optical element disposed in the distal portion, the collection optical element being light-transmissive to collect one or more of returned, backscattered or newly excited light from the targeted tissue region in response to the light emitted from the illumination or excitation optical element to the targeted tissue region;
• and
• a barrier disposed between the illumination or excitation optical element and the collection optical element to substantially prevent light from traveling between the illumination optical element and the collection optical element along a path within the distal portion,
• wherein the illumination or excitation optical element and the collection optical element are axially spaced from one another and axially optically isolated from one another within the distal portion by the barrier.