Design and implementation of olive oil laser by flashlamp pumping.

number: 
2226
إنجليزية
Degree: 
Author: 
Ansam Majid Salman
Supervisor: 
Dr. Anwaar A. Al-Dergazly
Dr. Mohammed A. Hussain
year: 
2009
Abstract:

This work includes the design analysis, designing, and implementation of a dye laser system based on using olive oil as the active laser medium. The threshold pumping power and energy required for different absorption peaks of the olive oil absorption spectrum have been determined. Resonator design has been characterized for different types and parameters, where a plano-concave resonator is selected for experimental implementation. The experimental resonator consists of a 5m radius of curvature gold coated copper rear mirror, and a flat, 50% reflectivity quartz output coupler. Two resonator lengths have been utilized, 33.5cm and 6.7cm, for two different sets of laser mode size. The olive oil introduced in a quartz cuvet for 2 cm3 volume. Two pumping sources have been experimented: 1. A SHG Nd:YAG, 532nm wavelength and 60mW, continuous power, focused to 67.74μm spot diameter using positive lens. 2. A linear flashlamp of 10cm length and 4mm bore diameter. A 1.5 kV, DC power supply for the flashlamp has been designed and built with a total output electrical energy of 22.5J. External triggering capable of 20kV potential with single pulse manual operation has been provided. Two cavity arrangements for the flashlamp pumping have been tried; one with a bare flashlamp, and the second with a semielliptical aluminum reflector of 5cm semi-major axis, 4cm minor axis, and 68.5% estimated geometric efficiency. With using a bare flashlamp, the overall laser efficiency has been estimated to be 0.05% and the slope efficiency is 0.033%. But when using cavity reflector the overall efficiency has been estimated to be 0.425% and the slope efficiency is 0.375%. When using a SHG Nd:YAG laser as pumping source, there is no output laser because the power intensity of the laser is smaller than the threshold power intensity at absorption peaks of 532nm. This pumping source has resulted in fluorescence of the olive oil at 670nm. The power intensity of the flashlamp using a cavity reflector exceeds the required threshold power intensity for the absorption lines 532nm and 670nm. Yet no proper detection device was available for the output emission, which is suppressed by the flashlamp radiation flood.