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Full-Text Articles in Engineering
The Lunar Date Of Ramesses Ii, Lee W. Casperson
The Lunar Date Of Ramesses Ii, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
Due largely to the efforts of R. A. Parker, the various calendars used in Egypt are now fairly well understood. Dates which the Egyptians expressed in both their civil and lunar calendars can sometimes be determined exactly, and the study of such dates has been extremely important in efforts to establish an accurate Egyptian chronology. However, the successful use of this method obviously depends on one's ability to reconstruct accurately the astronomical and observational conditions on which the lunar calendar was based. The author re-examined the methods used to calculate lunar dates and have suggested some ways in which those …
Spectral Behavior And Pulse Train Instabilities Of A Synchronously Pumped Mode-Locked Dye Laser, Duncan Leo Macfarlane, Lee W. Casperson, Anthony A. Tovar
Spectral Behavior And Pulse Train Instabilities Of A Synchronously Pumped Mode-Locked Dye Laser, Duncan Leo Macfarlane, Lee W. Casperson, Anthony A. Tovar
Electrical and Computer Engineering Faculty Publications and Presentations
The pulse-train envelope of a synchronously pumped mode-locked dye laser has been experimentally studied as a function of cavity length detuning. When a bandwidth-limiting birefringent tuning filter is included and the cavity is adjusted to the length that yields optimally short (˜2-psec) pulse, there is a slow (≤800 kHz), erratic amplitude modulation that provides a 20% variation in pulse energies. As the cavity length is detuned on the order of one part in 10⁴, the modulation vanishes, but the individual pulse lengths increade dramtically. Further detuning results in a clean periodic envelope with a 20% modulation depth and a˜5-μsec period. …
Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators, Lee W. Casperson
Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
Spontaneous pulsation phenomena in xenon lasers are now well known, and related effects have been observed with other laser types. Most theoretical analyses of such pulsations are formulated for unidirectional ring lasers, whereas most experiments involve standing-wave resonator geometries. Described here are rigorous semiclassical models governing the spontaneous pulsation instability in standing-wave laser oscillators. The standing-wave results are more complex and closer to experimental observations than the ring results for operation in the Lambdip region near line center.