A catheter is adapted to ablate tissue and provide optically-based lesion qualitativeand quantitative monitoring, comprising a catheter body and a tip electrodedistal the catheter body adapted for ablating tissue, the tip electrode havinga shell and an alignment member defining a hollow distal portion therebetween.In accordance with the invention, the catheter further includes a pluralityof optical waveguides adapted to transmit optical energy to and from the tip electrode.A distal portion of each waveguide extends through the hollow distal portionand terminates in openings formed in the shell. Advantageously, the alignmentmember fixedly secures the distal portion of each waveguide against movementrelative to the alignment member and the shell.
