Image Credits and References:
Left is an N2 laser from Jarrod Kinsey at http://www.youtube.com/watch?v=GDJ316rt41M. The butter tub houses a spark gap and the medicine bottles contain coins to hold down the electrodes.
The task is to design, build and test a table-top nitrogen (N2) laser operating at 120 pps in air with some nitrogen enrichment. The nitrogen gas is excited by a pulsed electric circuit that produces a fast discharge between two, 15-cm long electrodes spaced about 1mm. The discharge excites the nitrogen to an upper energy state where it emits at 337-nm photon while falling to a lower energy state, as shown in the diagram. The ultraviolet light from the N2 laser is used to pump a dye cell that produces laser light of various colors, depending on the dye selected. The project also includes a search by team members to locate and test common household materials that will lase when pumped by UV light.
Level of Difficulty: Medium
population inversion, wavelength, optical pump, coherence, monochromatic, stimulated emission, spontaneous emission, photon, optical resonator, superradiance, vector-inversion generator, Blumlein, Townsend discharge, dye laser
Tutorial on N2 laser construction at http://www.sparkbangbuzz.com/tealaser/tealaser7.htm
Farooq Kyeyune, “Investigation of the Electronic Discharge Circuit of a N2 Laser,” African Institute for Mathematical Sciences (AIMS), Laser Research Institute, Stellenbosch University, South Africa May 19, 2011, http://archive.aims.ac.za/system/app/pages/search?scope=search-site&q=Farooq+Kyeyune
Leslie Wright, “Nitrogen Laser,” 2007 http://www.fineartradiography.com/hobbies/lasers/nitrogen/
Electrical Engineer (2) – The Electrical Engineers on the project are responsible for the N2 laser’s power system, spark gap design, electrode configuration, and gas feed. Furthermore, the Electrical Engineers will model the network and laser discharge so the theoretical results can be compared with measurements. Laser performance enhancements will be explored and include gas mixtures, spark gap triggering, single cavity reflector, and laser-cavity preionization.
Mechanical Engineer (2) – The Mechanical Engineers are responsible for the design of the N2 laser’s mechanical layout, including a critical electrode adjustment device that sets the discharge gap and makes the electrodes absolutely parallel. The Mechanical Engineers are also responsible for integrating the N2 and dye lasers into a package that can be set up in public to show off the laser light while keeping innocent spectators safe from optical, chemical and high-voltage hazards.
Physicist (1); Chemist (1) – The Physicist and Chemist are responsible for the design and construction of the dye laser. The Physicist will design the optical system that concentrates the UV laser light into a dye cuvette and extracts the dye light into a collimated beam. The Chemist is responsible for understanding the handling of laser dyes and solvents and will be the sole person on the project to prepare commercial dye concentrations and dispose of them properly. Both Physicist and Chemist will work with the Mechanical Engineers.
Computer Scientist (2) – The Computer Scientists are responsible for the design and construction of the ultra-fast electrical and optical diagnostics used on the project and validating the data acquired. Furthermore, the Computer Scientists are responsible for coordinating all interlocks to assure the safety envelope cannot be violated for public demonstrations.
Designer (2) – Designers on the project blend the design goals of the various teams 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.