Continuous-wave carbon dioxide laser system producing output power up to 135 kW

Abstract

The operational characteristics of a 135kW continuous wave carbon dioxide laser system are described. A brief description of the fast-flowing electrical discharge coaxial laser system is presented followed by a detailed discussion of the operational and output characteristics of the device.Diagnostics systems configured to measure electrical discharge voltage and current, mass flow, laser cavity pressure, laser output power, output spatial intensity distribution and output temporal stability are described. The data collected with these systems are summarized with subsequent analyses presented and compared with theory. The 135kW carbon dioxide laser is located at the Laser Hardened Materials Evaluation Laboratory (LHMEL) at Wright-Patterson Air Force Base, Ohio, USA. The device was developed and is currently operated for the purpose of characterizing the thermal response of materials. 135 kW FAST-AXIAL FLOW LASERThe LHMEL 135kW carbon dioxide laser system was developed to characterize the response of materials subjected to extreme thermal conditions.' The device was designed to meet specific operational parameters required for materials testing, namely, output beam power level to 100kW while maintaining optimum spatial uniformity and temporal stability. The device, first operated in August 1989, demonstrated volume scaling principles for electric discharge coaxial lasers (EDCL).2 Shown schematically in Figure 1, this fast-axial flow system operates in open-loop configuration for durations of up to 80 seconds at a maximum power of 135kW. A careful balance between the performance limiting factors of flow velocity (M), electric field (E), electron number density (fle), pressure (P), number of excited molecules (N) and power deposition into the gas resulting in temperature change (tT) governs the operation of the EDCL. For optimized operation, an energy balance condition must be established where the product of electron number density and the time required for a molecule to traverse the discharge flow length is constant. 186 SPIE Vol. 3092 • 0277-786X/97/$1 0.00 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/24/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

Essential building blocks for a flexible approach to laser source design

“…These parameters are tailored to the main applications, laser cutting and welding, and are by no means the limit of the technology. Power levels of 100 kW and above [2] have been demonstrated and fundamental mode operation is easily achievable. Figure 1 shows a multi-kilowatt fast-flow CO 2 laser.…”