Fiber Lasers are emerging as a technically superior solution that is disruptive to conventional laser sources. Estimates place the 2005 market for Fiber Lasers at approximately $160Million, with growth potential of 100%/year for the next 3-4 years. Many of the applications envisage deployment where end-users have easy access to the benefits of the Fiber Laser source, without needing to understand the detailed physics and engineering behind the beam delivery. For these applications a comprehensive control platform with simple functional user interfaces is a significant competitive advantage.
Depending on the nature of the particular application, effective controls can range from basic pump source management, to more detailed monitoring of multiple aspects of the lasing system to ensure the desired operating regime, and may even include feedback from external sensors to optimize delivery conditions.
This paper presents the performance characteristics and reliability data of GaInAsP- and AlGaInP-based laser diodes emitting at the wavelengths from 650 to 1,300 nm. The lasers are grown by toxic-gas-free all-solid-source molecular beam epitaxy (SS-MBE).
InGaAs/GaInAsP/GaInP ridge waveguide 980-nm laser diodes for pumping light into erbium doped fiber amplifiers are reviewed. These lasers have very good performance characteristics. They exhibit kink-free, single mode emission up to a power of 250 mW with a slope efficiency of 0.7 to 0.95 W/A, a thermally limited maximum power of 450 - 500 mW, and the threshold current density of about 150 A/cm2. They are relatively stable against temperature variations. A 100 mW power from a fiber-pigtail module has been demonstrated. The lasers withstand severe thermal roll-over tests without showing degradation effects. Preliminary lifetime tests indicate that their mean-time-to-failure may be very high if not limited by sudden failure, from several hundred thousand to one million hours.
Laser diodes and superluminescent diodes have been fabricated using epitaxial structures employing a strained quantum well of InAlGaAs. These devices emit at wavelengths in the 800 - 900 nm range commonly addressed using unstrained GaAs quantum well structures. Results are presented which indicate that the strained layer devices exhibit a marked immunity from sudden unexpected ('freak') failure modes.
We describe the design, growth by atmospheric pressure metalorganic chemical vapor deposition (MOCVD), processing and characterization of single quantum well separate confinement strained layer InGaAs-GaAs quantum well lasers designed for high power operation at emission wavelengths near 1064 nm. Threshold current density is reduced by 39% for long cavity devices through design optimization. Broad area lasers operate at high cw (> 5 W) and pulsed (> 20 W) powers, with low threshold current density and high power conversion efficiency. Index guided ridge waveguide lasers show stable single spatial mode operation over a wide range of output power and temperature.
We describe 2.5Mm wide Ridge Waveguide Lasers emitting in the wavelength range 1045nm-1065nm. These are fabricated from strained layer single quantum well epitaxial heterostructures with 30%-31% InAs in the quantum well. The devices exhibit stable single spatial mode, single spectral line operation over a wide range of output power and temperature. Preliminary data suggests that reliable high power CW operation may be obtained.
We describe 2?m wide ridge waveguide lasers emitting at a wavelength of 980nm using a strained single quantum well epitaxial structure. These devices exhibit high coupling efficiency into single mode fiber. We have coupled up to 60mW using an industry standard 14-in dual-in-line package. Such devices are ideal for pumping Er-doped Fiber Amplifiers.