Optical coherence tomography probe for crossing coronary occlusions

A guide wire, comprising:

• at least one optical fiber configured to transmit a source beam of radiation, and
• a housing, comprising:
• a flexible substrate comprising a plurality of waveguides patterned thereon, wherein at least one of the plurality of waveguides is configured to transmit one or more beams of radiation away from the guide wire and at least one of the plurality of waveguides is configured to receive one or more beams of scattered radiation that have been reflected or scattered from a sample,
• a multiplexer configured to generate the one or more beams of radiation from the source beam of radiation,
• one or more ports through a wall of the housing,
• one or more optical elements configured to at least one of focus and steer at least one of the one or more beams of radiation, and
• one or more reflecting elements configured to direct the at least one of the one or more beams of radiation towards corresponding ports of the one or more ports.