30W FIBER COUPLED LASER DIODE OPTICAL MODULE FOR MEDICAL APPLICATIONS

摘要

We developed the fiber-coupled optical module using two laser diode arrays (LDAs) at the wavelength of 1460 nm for the medical applications because the wavelength of around 1460 nm have the absorption peak for fat and water simultaneously. We combine two beams from the two LDAs by spatial multiplexing. The two beams of the LDAs vertically collimated and rotated by micro optics called beam-transformation system (BTS) are collimated by a cylindrical lens and combined by a folding mirror carefully with different height to be parallel. Then the paralleled beams is focused by a aspheric lens and coupled to a fiber with core diameter of 600 um, numerical aperture of 0.37. The maximum optical power is 31 W at the end of the fiber. The corresponding coupling efficiency is 82.4% at the current of 50 A and at the temperature of 20 °C. The result shows the total optical system efficiency of 77% from 2 LDAs to the end of fiber.