Optical-fiber-tip temperature control system for fiber-coupled laser modules in medical equipment

An optical-fiber-tip temperature control device embedded into the power-supply unit of high-power laser diodes and modules (with fiber-optic output) used in medical laser equipment is proposed. As the sensing element, a III–V mid-infrared photodiode developed at the Ioffe Physical-Technical Institute is chosen from the photodiode class whose parameters are optimal for developing multipurpose thermal-radiation detectors (pyrometric sensors). The developed device allows temperature control at the working tip of the optical fiber of the laser “scalpel” in the range of 600–1100$^\circ$C with an error no worse than 1% for a response time of 1 ms. The device has digital and analog temperature-signal outputs, which can be used to control the laser pump current, thus extending the functionality of medical laser equipment, increasing its efficiency, safety, and service life.