Coherent Uses Diode Lasers for Gold Soldering

SANTA CLARA, Calif., Feb. 1 -- Coherent Inc's. Laser Processing Center has developed a new method for employing high-power diode lasers to solder gold-metallized telecommunications fibers to gold-plated substrates.

To overcome typical complications of soldering gold-plated objects, the Laser Processing Center is using a high-power 40-watt NIR fiber array package (FAP) system equipped with a standard 1:1 optics imaging accessory, said Tony Hoult, applications manager. To initially prove the feasibility of diode lasers for gold-tin soldering, Hoult said he placed a number of gold-plated telecom fibers on a piece of gold-plated stainless steel with a 25-mm thick gold-tin preform and applied an 800-mm-diameter spot from the FAP system. By strictly controlling the beam's timing, positioning and pulse, Hoult said he produced defect-free joints with no associated damage to the fiber.

Hoult contrasts Coherent's FAP system soldering scheme with the solid-state laser-based welding systems that are currently being used for this fiber attachment application.