In order to evaluate and obtain the actual lifetime data of high power laser diodes, an automated high power laser diodes
reliability experiment was developed and reported in this paper. This computer controlled setup operates the laser diodes
24 hours a day, the parameters such as output power, wavelength were test once in one hour. The experiment has 60
work stations, the temperature control range is from 25°C to 70°C, and the output power of the aging device is beyond
We have set up a computer automated controlled diode array reliability experiment which can take up 10 to 20 high
power cm-bars. Subsequent 25°C and 50°C lifetime tests were completed. According to the method of least squares, the
degradation model of cm-bars is obtained. Using the model and weibull++7 software, the extrapolated lifetime of cmbars
at 25°C is 7950 hours (2.86×10<sup>9</sup> shots). We also obtain an acceleration factor 1.88 of resulting in a thermal
activation energy of Ea=0.21eV using Arrhenius function. Finally, failure analysis was carried on the gradually degraded
devices, the results show that it is the facet degradation which made high power cm-bars degrade during the long time
Firstly, the vertical external-cavity surface-emiting lasers (VECSELs) device structure and
model was given, and the output characteristic was simple calculated. Then, in experiment, the
VECSELs were grown, bonded on to the heat sink, and optically pumped by high-power 808nm diode
laser array with fiber output module, the light emission spectra were measured. Finally, The thermal
characteristic of the VECSELs was investigated by changing the temperature of the substrate.
High-power vertical-cavity surface-emitting lasers with InGaAs/GaAs quantum well active gain region
are investigated. By using AlAs oxidation technology, the devices have been fabricated in experiment, and the
characteristics of the device are carried out at room temperature. The 300μm-diameter VCSELs have the maximum
room temperature continuous wave (CW) optical output power of about 1.1W, and the threshold current of the device is
about 0.46A. The life test of the device is carried out in constant current mode. The life test of 300-μm diameter lasers
shows that the average lifetime is about 1800h at 80°C. The device degradation mechanism is also discussed in detail.
By using bottom-emitting structure, we will develop laser diode (LD) pumped 980 nm VECSEL with active region of InGaAs/GaAsP/AlGaAs system. Because the thickness of barrier layer and absorption layer exceed that of quantum well, single well approximation model (KP method) can be used to calculate the band structure of VECSEL. The Schrodinger equation of finite deep potential well can be adopted to calculate the energy level structures of electron, heavy and light holes. According to the transition selection rule, we theoretically obtained the emitting wavelength of VECSEL and calculated quasi-Femi energy of valence band and conduction band based on the analysis of energy level structure of electron and holes. By analyzing the gain of strained quantum wells, we calculated the gain of VECSEL using transition matrix elements of electron, heavy and light holes. We give out the threshold gain, output power and other characteristic parameters. We will study the configuration of VECSEL and pumping scheme. We designed external cavity mirror, active region and bottom-emitting structure. A LD-pumped vertical external cavity surface-emitting laser whose output power is greater than 1.0 W can be predicted.
In this paper high power diode array module with an emission wavelength of 1.06μm is presented. The epitaxial structure is an InGaAs/GaAsP strained-compensated single-quantum well structure. Laser bars with a fill factor of 50% are processed and show a good temperature characteristics with a slope efficiency only decreasing from 1.08W/A to 1.06W/A when the temperature of heat sink changes from 20<sup>o</sup>C to 40<sup>o</sup> C. The module's CW output power can reach to 68.5W at a current of 80A when the temperature of cooling water is 20<sup>o</sup> C. The central wavelength is 1059.4nm.
The high power bottom-emitting vertical-cavity surface-emitting lasers (VCSELs) and laser arrays emitting at 980 nm are reported. Extensive investigations on size scaling behavior of thermal properties of single devices show limits of attainable output characteristics. The maximum continuous wave (CW) output power at room temperature of single devices with aperture size up to 500 μm is as high as 1.95 W. The key characteristics such as maximum output power, wavelength and thermal resistance are discussed. The bottom-emitting arrays of 16 elements and 200 μm aperture size of individual elements show output power of CW 1.35 W at room temperature. The far-field angle is below 17° for all driving current, which is very favorable for focusing or collimating optics.
We describe design, numerical simulation and characteristics of high-power optical pumped VECSELs at different wavelength (980nm, and 1300nm). The device design realizes the integrating diode-pumped lasers with vertical-cavity surface-emitting laser structure, drawing on the advantages of both. With periodical gain element structure, optical pumped VECSEL is scalable to watt level output. The characteristics such as threshold condition and output power are calculated theoretically. An optimum number of quantum wells and external mirror reflectivity are obtained from the calculation results, and the thermal characteristic is also considered. Finally the calculation results also predict high output power in this kind of device structure.
We describe the design, fabrication, and calculation characteristics of the 980nm high-power diode-pumped vertical external-cavity
surface-emitting laser(VECSEL).From our calculation, the VECSEL with active region of InGaAs/GaAsP/AlGaAs system can operate near 1w in a single transverse mode.