The creation and characterization of chemically created atomic population inversions for the development of a visible chemical laser.

摘要

The possibility of developing a chemically pumped laser in the visible region has been investigated. First, the history and the recent developments of short wavelength chemical lasers (SWCL) were reviewed. The energy transfer pumped thallium self-terminating visible chemical laser and the chemically pumped sodium dimer laser amplifier developed previously in the Georgia Tech chemical physics laboratory were discussed in detail. Combining the basic knowledge of laser physics, gas dynamics, reaction chemistry and the experience accumulated by other researchers in the past quarter century, a mode of energy transfer pumping of an atomic laser medium is adopted.; Efficient near-resonant energy transfer involving metastable excited states of SiO* (or GeO*) and ground state alkali (Na and K) or copper atoms have been realized. The energy donors, SiO* (or GeO*) in {dollar}rm asp3Sigmasp+{dollar} and {dollar}rm bsp3{lcub}bfPi{rcub}{dollar} states, were generated in high yield from {dollar}rm Si+Nsb2O{dollar} (or {dollar}rm Ge+Osb3){dollar} reactions. The energy stored in these triplet states is transferred in a near resonant process to excite sodium to its {dollar}rm 3dsp2D, 4dsp2D{dollar} and {dollar}rm 5ssp2S{dollar} states. {dollar}rm(5dsp2D, 6ssp2S{dollar}.. in potassium and {dollar}rm 4psp2psp0{dollar} in copper.); An electronically inverted atomic configuration in sodium atoms is formed from highly efficient near resonant intermolecular energy transfer using a newly developed chemical laser apparatus. Evidence was shown that the Si-N{dollar}sb2{dollar}O-Na system satisfies the basic requirements for a visible chemical laser and has the potential to lase at a few hundred milliwatts at 569nm in the current laboratory scale apparatus.; Gains were measured in the Si-N{dollar}sb2{dollar}O-Na system using three different methods. With an amplified spontaneous emission (ASE) method, gains at {dollar}lambda{dollar} = 569,616 and 819nm, corresponding to the {dollar}rm 4dsp2D, 5ssp2S{dollar} and {dollar}rm 3dsp2D{dollar} to {dollar}rm 3psp2P{dollar} transitions, were detected. Gain at 569nm was also measured with a sodium discharge lamp and with a single mode dye laser. Efforts are also made to oscillate the sodium {dollar}rm 4dsp2D{dollar}-{dollar}rm 3psp2P{dollar} transition at 569nm. Evidence from full optical cavity experiments demonstrated that the output intensity has exceeded the chemiluminescent intensity, indicating light amplification and initial oscillation.