Reliability of High Power Pump Lasers for Erbium-Doped Fiber Amplifiers

Abstract

The degradation behavior and the reliability of 980 nm lasers and 1480 nm lasers are reviewed and discussed. In addition, packaging problems for the high power lasers are also discussed from the application viewpoint. For 980 nm lasers the reliability in laser chip is limited mainly by the instability of an interface between the laser material (facet) and the anti-reflecting coating film, and for most 1480 nm lasers the reliability of the laser chip is determined mainly by the instability of a buried heterointerface. These reliability problems have been solved, however, by examining the material properties and improving device fabrication technology. The main packaging problem is a packaginginduced failure (PIF) causing sudden failure in 980 nm lasers sealed in dry N2 or Ar, but packaging problems have also been suppressed or eliminated. The device technology and packaging technology needed to make high power pump laser modules have been established, and erbium-doped fiber amplifiers pumped by these lasers are indispensable components of many optical transmission systems. 55 Current Trends in Optical Amplifiers and Their Applications Downloaded from www.worldscientific.com by UNIVERSITY OF BIRMINGHAM LIBRARY -INFORMATION SERVICES on 03/21/15. For personal use only. Current Trends in Optical Amplifiers and Their Applications Downloaded from www.worldscientific.com by UNIVERSITY OF BIRMINGHAM LIBRARY -INFORMATION SERVICES on 03/21/15. For personal use only.

Catastrophic facet and bulk degradation in high power multi-mode InGaAs strained quantum well single emitters

“…The COMD process for single-mode InGaAs-AlGaAs strained QW lasers has been extensively investigated for over a decade [21,22]. The COMD is due to an increase in facet temperature via carriers from the surface currents as well as from absorption of lasing photons that eventually leads to facet melting at localized area.…”

Reliability and failure-mode investigation of high-power multimode InGaAs strained quantum well single emitters

“…A number of groups have investigated the mechanism that leads to COMD in single mode InGaAs-AlGaAs QW lasers for over a decade, and their findings propose the following three steps in order for the COMD process to take place: (1) generation of point defects at the facet (most likely Group III vacancies), (2) diffusion of defects into the laser cavity under device operation, and (3) COMD due to thermal runaway. 20 The instantaneous increase in facet temperature that eventually leads to facet melting via thermal runaway is the combined effect of absorption of lasing photons at the facet and non-radiative recombination of carriers at the facet. The same process is expected to take place for broad area multi mode InGaAs-AlGaAs strained QW lasers to fail due to facet COMD.…”