V F Pevtsov

Spectral features and thermal resistance of 976-nm cw laser diodes with a power up to 15 W

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.

Limiting parameters of high-power single-stripe laser diodes in the range of 800–808 nm in the pulsed mode

Experimental results on the study of the output parameters of high-power continuous-wave (cw) laser diodes operating in the pulsed mode and the results of numerical simulation of the total efficiency of laser diodes with cavity lengths of 3 and 4 mm in a wide range of pump currents are presented. The spectral parameters of the high-power laser diodes are studied at various pulse-repetition rates. The possible causes of the limited output power in the pulsed mode are discussed.

Dual-wavelength generation at the transverse mode locking in a diode-end-pumped passively Q-switched Nd:YLF/Cr4+:YAG laser

A dual-wavelength generation at 1047 and 1053 nm is implemented in a diode-endpumped Nd:YLF laser Q-switched by Cr:YAG. This generation is obtained by the tuning of the cavity length near the regions of the transverse-mode degeneracy.

The peculiarities of spectra in high power 970 laser diodes

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.

Thermal Condition of High-Power Laser Diodes

Light-current and current-voltage characteristics of a set of high-power laser diodes of the spectral region of 980 nm, fabricated by the authors, are experimentally studied. The dependences of their total efficiency and heat load on the pump current are constructed. The latter experimental dependence is used for calculations in the three-dimensional thermal model of the laser diode with a stripe contact width of 100 µm. Thermal fields are studied and isothermal surfaces are constructed for laser diodes fabricated on C-mount heat sink elements under heat loads corresponding to output powers of 10 W and higher in continuous mode.