A laser catheter system to ablate blockages in body lumens using high energy and high power short duration laser pulses, comprising: a high energy, high power short duration ultraviolet pulsed laser source; and a low profile, kink resistant, torqueable liquid core ablation catheter operatively coupleable to the laser source, comprising: an elongate multi-layer catheter tube including a thin inner luminal film of a low index of refraction IR, U.V. transparent, amorphous fluoropolymer having an index of refraction of less than or equal to about 1.33 coated onto an inside surface of a base tubular layer; an ultraviolet grade output optical window or window assembly sealed to a distal end of the catheter tube, wherein the output optical window is secured to the distal end of the catheter tube with a tapered metal housing disposed at a distal end of the catheter tube; an ultraviolet grade input optical window sealed to a proximal end of the catheter tube to create a fluid tight core liquid volume; and a biocompatible U.V. transparent fluid disposed within and completely filling the core liquid volume formed between an inner surface of the thin inner luminal layer, the output optical window and the input optical window. a high energy, high power short duration ultraviolet pulsed laser source; and a low profile, kink resistant, torqueable liquid core ablation catheter operatively coupleable to the laser source, comprising: an elongate multi-layer catheter tube including a thin inner luminal film of a low index of refraction IR, U.V. transparent, amorphous fluoropolymer having an index of refraction of less than or equal to about 1.33 coated onto an inside surface of a base tubular layer; an ultraviolet grade output optical window or window assembly sealed to a distal end of the catheter tube, wherein the output optical window is secured to the distal end of the catheter tube with a tapered metal housing disposed at a distal end of the catheter tube; an ultraviolet grade input optical window sealed to a proximal end of the catheter tube to create a fluid tight core liquid volume; and a biocompatible U.V. transparent fluid disposed within and completely filling the core liquid volume formed between an inner surface of the thin inner luminal layer, the output optical window and the input optical window. an elongate multi-layer catheter tube including a thin inner luminal film of a low index of refraction IR, U.V. transparent, amorphous fluoropolymer having an index of refraction of less than or equal to about 1.33 coated onto an inside surface of a base tubular layer; an ultraviolet grade output optical window or window assembly sealed to a distal end of the catheter tube, wherein the output optical window is secured to the distal end of the catheter tube with a tapered metal housing disposed at a distal end of the catheter tube; an ultraviolet grade input optical window sealed to a proximal end of the catheter tube to create a fluid tight core liquid volume; and a biocompatible U.V. transparent fluid disposed within and completely filling the core liquid volume formed between an inner surface of the thin inner luminal layer, the output optical window and the input optical window.