COAX products - Modulight

High power lasersModulight’s unmountedlaser bars.The applications of ‘Diode Pumped Solid StateLasers’ (DPSSL) have experienced a rapid developmentin a large number of activities fromindustrial, medical, space and defence. Thesenew activities are made possible by developmentof new performance in “High Power Laser Diodes”(HPLD). Modulight’s HPLDs are used for pumpingDPSSL. The main applications are materialprocessing, medical therapy, measurement andanalysis, printing and imaging, and spectroscopy.High Power Laser Diodes for DPSSLModulight manufacturers high power laser diodes(Fig. 1.) operating in the wavelength range ofabout 0.78 to 1.1 micron. These lasers are usedin optical pumping of solid state lasers, suchas the Nd:YAG, replacing traditional flash lampdesigns. High-power laser diodes are tuned to theabsorption band of the dielectric crystal resultingin much more efficient pumping of the laser rod,from which a high-power focused coherent beamof light is emitted. This beam can then be usedin a variety of industrial, medical, and militaryapplications. Laser diodes have been developedto match the absorption bands of a variety of dielectriccrystals in a broad wavelength range.The laser diodes are packaged in individualheatsink assemblies in order to have continuouswave (CW) operation (Fig. 2). These individualheatsinks could be stacked to form a linear arrayof CW laser diodes.of kilowatts. Typically, direct diode lasers operateat a shorter wavelength than the Nd:YAG (1.06µm) and CO2 (10.6 µm) lasers, which are commonlyused in industrial applications. This leadsto an advantage of the diode laser system, sincethe lower operating wavelength results in a higherabsorption rate with most metals. This is especiallytrue for aluminum in which the absorptionpeak is at the HPDL wavelength of 810nm. Inthe case of laser heat treating, diode lasers donot require pre-coating of metal parts in orderto achieve higher absorption as with the case ofCO2 lasers.The advantages of direct diode lasers are the highwall plug efficiency, order of magnitude smallerfootprint, lower maintenance, high absorptionin work piece, and high control bandwidth. TheHPDL are very small and compact, such that theentire laser head can easily be mounted to theend of the robotic arm or gantry for use.A further advantage of direct diode lasers is thatthey are solid-state lasers. This yields a highlycontrollable heat source. Unlike conventional systems,diode lasers do not require warm up timeto stabilize. Power can also be turned on and offinstantaneously, which realizes additional energysavings.Example of high-power laserdiode package.High Power Laser Diodes for DirectprocessingIn addition to applications involving the pumpingof solid state laser rods, Modulight’s high-powerlaser diodes are also used for direct processinglike marking, welding, and cutting of metalsand various other materials. This is possible bystacking several high-power laser diode bars ontop of one another to make stacked laser diodearrays with output powers potentially in the range46