Image Credits and References:
Lots of advice on CO2 laser construction; http://www.repairfaq.org/sam/lasercc2.htm#cc2toc
Homebuilt CO2 Laser from Jarrod Kinsey; http://jarrodkinsey.org/co2laser/co2laser.html#action
DIY 80-watt CO2 laser operating in the field; https://www.youtube.com/watch?v=BDks2e438hs
CO2 laser use in Dermasurgery; http://www.medicalindiatourism.com/skinalive/co2-laser.html
The task is to design, build and test a continuously operating high-power CO2 laser with an output power of 50 watts. The laser is a collection of numerous technologies that include an optical system, flowing gas-vacuum system, closed loop cooling, a high-voltage DC power supply, and various diagnostics to measure gas pressure, optical power on target, and various electrical signals. The gas is a premix of 4.5% carbon dioxide, 13.5% nitrogen, and 82% helium. The gas is excited in a long 1.0-m discharge that is powered from a variable 0-30 kV power source. The energy level diagram shows that the light has two distinct wavelengths (colors) at 10.6 and 9.6 µm. The output from this type of laser is hazardous because the beam is invisible and the power level is high enough to cut through various materials, including steel. The laser will require a safety enclosure to protect observers from scattered light and high voltage.
Level of Difficulty: High
plasma, glow discharge, vibration state, coherent, stimulated emission, diffraction, reflection, Brewster's angle, zinc selenide (ZnSe), polarization
“How Lasers Work (in theory)”; http://www.youtube.com/watch?v=y3SBSbsdiYg
“Principles of Laser Action”; http://worldoflasers.com/laserprinciples.htm
Electrical Engineer (2) – The Electrical Engineers on the project are responsible for the design and construction of an adjustable 30-kV, 450-W power supply. The supply is enabled from an interlock system that assures a protective beam enclosure is in place before operation. The high voltage is applied to a quartz laser discharge tube that is surrounded by a water cooling jacket.
Mechanical Engineer (2) – The Mechanical Engineers are responsible for the design and construction of the high-vacuum and flowing gas system. The system must pump out the air and replace it with a flowing stream of CO2: N2: Helium gas mixture with a base pressure of a few Torr. Additionally, the MEs will design a closed-loop water cooling system that removes heat from the quartz discharge tube.
Physicist (2) – Physicists on the project are responsible for the design and construction of a rugged optical system that holds and adjusts the rear mirror and output optical coupler. The optical rail supporting the resonator optics must also support the laser tube, cooling jacket, and safety enclosure. The optical rail and enclosure admit connections to the gas-vacuum system, cooling water, and high-voltage power supply.
Computer Scientist (2) – The Computer Scientists on the project are responsible for the data-acquisition system that gathers and displays power system output, gas pressure, gas flow rate, cooling temperature and optical output from various sensors. The data is processed to help peak the laser’s performance by tuning the many system variables.
Designer (2) – Designers on the project blend the design goals of the various team members into a device that can be manufactured, maintained, assembled, transported, and is safe to operate in public demonstrations. Designers validate the system assembly with CAD illustrations and supervise all component manufacturing.
Journalist (1) – The Journalist documents the project’s progress on the website, communicates with the local media, and is responsible for a final report. The Journalist also works closely with the Multimedia Artist to provide video and graphic art displays for demonstrations that explain the project to the public. The whole project is your project.
Multimedia Artist (1) – The Artist also documents the project’s progress on the website and works with the Journalist to maintain the project’s presence on social media. Additionally, the Artist designs and organizes all public relations events to assure spectator safety and to enhance the community’s awareness of science and technology. The whole project is your project.
Business Manager (1) – The Business Manager is responsible for reporting the project’s progress against a predetermined schedule, determines critical path items to completion, and tracks project spending to assure that costs remain within a fixed budget. The Manager works with all team members to identify problems early and resolve them quickly. The whole project is your project.