Thermal- and spectral-characteristics of high-power quasi-continuous wave 940-nm InGaAs diode laser arrays

Experimental results of the thermal and spectral characteristics of a monol ithic stack of high power quasicontinuous wave 940-nm InGaAs linear laser d iode arrays have been evaluated. Thermal resistance as the most important t hermal parameter characterizing a high-power laser diode package was obtain ed using the temperature rise measured directly by a thermo-camera. A new s imple and convenient technique to measure a spectral transition of the emis sion from laser diode arrays is proposed. Spectral chirping due to the tran sient thermal power dissipated during the laser pulse was observed as a tim e-evolution of the spectral profile; it gave a comprehensible image of the chirping behavior. Comparing the temperature rise in the diode junction wit h the thermal simulation, it was determined that the thermal shift of centr al wavelength d lambda /dT was 0.21 nm/degreesC. Detailed performances were identified for pumping a Yb3+ doped crystalline laser, and it was verified that the laser diode arrays were satisfactory to meet pumping source requi rements for coupling to Yb3+ absorption linewidth.