Development of Low-Cost Prototype N<sub>2</sub> Laser System and Laser-Induced Fluorescence of Pyranine

Abstract

This work aims to a detailed description of the development of a prototype Transversely Excited Atmospheric (TEA) nitrogen laser and its high-tension electrical pump source, along with its application study of Laser-Induced Fluorescence (LIF). The high-tension pump source is designed and simulated by using NI Multisim to study the voltage behavior at different points. The high-tension pump source is constructed using the flyback transformer. The open-air laser cavity is designed and simulated by using Zemax Optic Studio. Blumlein transmission line equivalent of nitrogen laser is designed in NI Multisim, voltage and current behavior across laser cavity and spark gap are simulated. The air is used as a lasing medium, as it contains 78% molecular nitrogen. The L-shaped electrodes are used as a cavity in the construction of this N₂ laser system. An ignition system in the form of the low inductance spark gap is built using the two bolts. Generally, the current passes through gas either by transverse or longitudinal discharge; in this work, the transverse discharge technique is used. Nitrogen laser produces a beam with a center wavelength of 337.1nm. Laser-induced fluorescence spectrum of the Pyranine is taken which shows its fluorescence in the green region with a maximum peak at the wavelength of 567.5nm. Pyranine is made up of a mixture of C₁₆H₇Na₃O₁₀S₃ so some other peaks can also be seen in the fluorescence spectrum with low intensity.