Suppression of Lasing Wavelength Change of 980 nm Pump Laser Diodes for Metro Applications

High-power 980 nm laser diodes (LDs) are used as pumping sources of erbium-doped fiber amplifiers (EDFAs). Reductions of costs and power consumption in EDFAs are very important for access or metro applications. System construction without fiber Bragg gratings (FBGs) and thermal electric coolers (TECs) is strongly required. Therefore, high-power 980 nm LDs with small lasing wavelength changes under various operational conditions are highly desired in these systems. We proposed a new technique of wavelength change suppression using a facet coating for 980 nm LDs. Less than one-third reduction of lasing wavelength change was realized by this method. Moreover, the proposed LDs possess more than 350 mW output power even at 95°C and good reliability at 50°C with 700 mA automatic current control (ACC).