Packaging technology for high-power, singlemode-fiber-pigtailed pump laser modules for Er-doped fiber amplifiers

A packaging technology for efficiently coupling a conical microlens single-mode fiber to a laser diode has been developed. A two-step approach has been used in which angular and linear alignments are carried out separately by using reusable fixtures. A thermoelectric cooler and a thermocouple are used to maintain the laser at a constant temperature of 15°C. Using this approach, the authors have achieved submicron alignment between the laser and the lensed fiber and have obtained 106-mW fiber-coupled power in a 1480-nm wavelength packaged laser diode module which has been successfully used in pumping Er-doped fiber amplifiers