[en] We present the results of 3D thermal regimes modelling of CW laser diode arrays (LDA) assembled on the CS-mount type heat sinks. The dependences of the LDA temperature profiles on the fill factor (FF) of the LDA aperture at different levels of thermal load in different sections on LDA, including those inaccessible for direct experimental measurement calculated and discussed. (paper)

[en] We report emission parameters of high-power cw 980-nm laser diodes (LDs) with a stripe contact width of 100 μm. On copper heat sinks of the C-mount type, a reliable output power of 10 W is obtained at a pump current of 10 A. Using a heat flow model derived from analysis of calculated and measured overall efficiencies at pump currents up to 20 A, we examine the possibility of raising the reliable power limit of a modified high-power LD mounted on heat sinks of the F-mount type using submounts with optimised geometric parameters and high thermal conductivity. The possibility of increasing the maximum reliable cw output power to 20 W with the use of similar laser crystals is discussed. (lasers)

[en] The spectral characteristics of cw laser diodes with a maximum reliable power of 15 W mounted on F-mount heat sinks are studied. It is found that the spectrum envelopes have features at emission powers exceeding 5 – 7 W. A method for determining the maximum of a spectrum envelope under the conditions of its broadening and appearance of features is discussed. The thermal resistance of diodes is determined experimentally at pump currents from threshold to maximum (14 A) and is found to be 2.25 K W^-1 at a current of 10 A and 1.5 K W^-1 at a current of 4 A. The results obtained are compared with the literature data. The adequacy of using the thermal resistance parameter for comparing and estimating thermal characteristics of laser diodes is considered. (lasers)

[en] We have studied the key optical emission parameters of laser diodes (emission wavelength, 980 nm; stripe contact width, 95 μm) mounted directly on F- and C-mount-type copper heat sinks, without intermediate elements (submounts). When effectively cooled by a thermoelectric microcooler, the lasers on the F-mount operated stably at output powers up to 20 W. The lasers were tested for reliable operation at an output power of 15 W for 100 h, and no decrease in output power was detected to within measurement accuracy. The experimentally determined maximum total efficiency is 71.7% and the efficiency at a nominal output power of 15 W is 61%. We compare parameters of the laser diodes mounted on C- and F-mounts and discuss the advantages of the F-mounts. (lasers)

[en] Using three-dimensional thermal modelling of a highpower 980-nm laser diode with a stripe contact width of 100 μm as an example, we analyse the thermal parameters of high-power laser diodes mounted using submounts. We consider a range of thermal conductivities of submounts that includes parameters of widely used thermal compensators based on AlN, BeO and SiC, as well as on CuW and CuMo composites and polycrystalline and single-crystal synthetic diamond with high thermal conductivity. Taking into account experimental overall efficiency vs. pump current data, we calculate the temperature of the active layer as a function of the width, thickness and thermal conductivity of the submount at thermal loads corresponding to cw output powers of 10, 15 and 20 W. (lasers)

[en] We have designed and fabricated submounts from synthetic diamond grown by microwave plasma chemical vapour deposition and developed an economical process for metallising such submounts. Laser diode chips having an 808-nm emission wavelength, 3-mm-long cavity and 130-mm-wide stripe contact were mounted on copper heat sinks with the use of diamond submounts differing in quality. The devices were tested for more than 150 h in continuous mode at an output power of 8 W on diamond with a thermal conductivity of 700 W m^-1 K^-1, and no changes in their output power were detected. On diamond with a thermal conductivity of 1600 W m^-1 K^-1, stable cw operation for 24 h at an output power of 12 W was demonstrated. (letters)

[en] Crystals of high-power laser diodes are directly mounted on copper heat-removing elements. The maximum output power of 25 W is obtained many times in a 808-nm cw laser with the 150-μm-wide strip contact at 20⁰C. After training tests at the output power of 6 W for 200 hours, the yield of acceptable samples was 80 %. No changes in the output parameters were observed after tests for 70 hours at the output power of 8.5 W. Tests are being continued. (lasers)

[en] We present the experimental results regarding the thermal resistance measurements for 100 μm stripe laser diodes emitting in 980 nm spectral range. The dependence of laser thermal resistance on pumping current was measured for series of identical laser chips with resonator length 4 mm and stripe width 95 mkm assembled directly at copper C-mounts and F-mounts without thermo-compensating submounts inside the output power range 10 W and 15 W accordingly. The appropriate method of spectral envelope peak definition was used for output power range 5-15 W in which we observed spectral peculiarities associated with appearance and competition of several peaks at the spectral envelope. We have proposed an explanation of the obtained dependency based on their correlation with the dependence of the total efficiency of the laser on the pump current. (paper)

[en] We present the results of optical power, total efficiency and spectra of CW laser diodes emitting at wavelength 970 nm. Total efficiency in maximum 72% was measured and reliable operation at 15 W CW was achieved. At the base of measured CW spectral parameters in wide range of pump currents we discuss the possible reasons of observed features in dependences of spectral envelope, spectral maximum and spectral half-width against pumping current. (paper)