No abstract

High bit rate, WDM, networks are reliant on Er or Er/Yb doped fibre amplifiers. Reliable, high power laser diodes at 980nrn and 1480nm are key devices for pumping these amplifiers. We have developed several 980 nm laser diode structures at 980nm, using an Aluminium free active region and standard AR/HR coatings on the facets. Our lasers show low optical losses, low threshold current density and a high external differential efficiency. We demonstrate a mini-bar of small angle index guided tapered laser diodes (emissive width of 3 mm) with an optical output power of 20W at 33A under CW operation (25°C). The far field of the slow axis has a Gaussian single lobed shape, with a FWHM of 3.5°a t maximum power, which is two time less than obtained with multimode broad area lasers. With such a device, we expect to couple lOW into a 1OOtm diameter fibre. We also demonstrate a large aperture gain-guided tapered laser with an output power of 2.4W and a calculated M2l/ = 3, the M211 factor being calculated with the method based on measurements ofthe fields profiles widthes at l/e2. Keywords : semiconductor laser, high power laser diode, high brightness laser diode, broad area laser, tapered laser structure, index guiding, gain guiding, beam quality, bar of laser diodes, reliability, 980 nm.