Effect of the p

The degradation behaviour of two InGaAs/AlGaAs laser structures differing only in the Zn doping concentration of the p+ GaAs contact layer has been compared. The ageing tests used in this comparison are performed on lasers with Anti-Reflection (AR) coatings on both facets, so as to increase the carrier density in the quantum well and the gradual degradation rate. This kind of ageing test has been discussed in a previous paper, where a possible effect of Zn diffusion was suspected. The defects generated during ageing are studied by Low Temperature (80 K)—Spectrally Resolved Cathodo-Luminescence (LT-SRCL), Cathodo-Luminescence Imaging (CLI) and Transmission Electron Microscopy (TEM). The impact of the acceptor concentration in the contact layer is thus clarified

Reliable pulsed-operation of 1064 nm wavelength-stabilized diode lasers at high-average-power: boosting fiber lasers from the seed

ABSTRACT Most Pulsed Fiber Lasers (FLs) are built on a Master Oscillator -Power Amplifier (MOPA) architecture, as this configuration has the advantage, among others, of exploiting direct modulation of the diode laser seed (the MO) to reach high repetition rates and high peak-power pulsed operation. To enhance the FL global performance and reliability, high power single-lateral-mode 1064 nm diodes with outstanding long-term behavior are needed. The reliability of these devices at high power has been a challenge for years, due to the high built-in strain in the Quantum Well (QW). In this paper, we present excellent reliability results obtained, in both cw and pulsed conditions, on the latest generation of 1064 nm single-lateral-mode diodes developed at 3S PHOTONICS. Aging tests in cw conditions prove the intrinsic robustness of the diode even at very high junction temperatures, while specific tests in pulsed operation at 45 °C heat-sink temperature, and high repetition rates of several hundred kHz, confirm the stability of the devices in accelerated conditions directly derived from real applications. Both free-running and wavelength stabilized (by means of a Fiber Bragg Grating (FBG)) packaged devices show very stable performances under pulsed conditions. Reliable operation at higher average power than currently commercially available diode lasers seeds is demonstrated