Topic
Ruby laser
About: Ruby laser is a research topic. Over the lifetime, 2474 publications have been published within this topic receiving 38933 citations. The topic is also known as: corundum laser & ruby rod.
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TL;DR: In this paper, the dual channel triggering of a spark gap switch by fiberoptic transported ruby laser radiation is discussed, and the correlation of this behavior with the space charge build up in the slightly over-volted gap is discussed.
Abstract: The dual channel triggering of a spark gap switch by fiberoptic transported ruby laser radiation is discussed. The spark gap is the output switch of a 20-ns water dielectric Blumlein generator. The Blumlein generator is pulse charged in approximately 250 ns by a three-stage Marx bank to 150 kV. The spark gap is operated at a pressure of 2540 torr with a mixture of Ar and N2 gas and an electrode separation of 2 cm. Two 1-mm diameter quartz optical fibers are used to transport 2 2-MW laser beams into the spark gap onto points 6 cm apart on the target electrode. The two beams are obtained by optical splitting of the output of a single laser. Under appropriate conditions, two arc channels are initiated by the laser beams along their paths. A small improvement in current rise time for dual channel events over single channel events is observed. Moreover, the number of successful dual channel events is observed to depend on the time of laser entry with reference to the beginning of the charging pulse, and not the gap polarity. The correlation of this behavior with the space charge build up in the slightly over-volted gap is discussed.
13 citations
Journal Article•
TL;DR: Laser is one of the greatest technical discoveries of the 20th century and is important in basic sciences, but particularly in diagnosis and therapy of various pathologic conditions of human organism.
Abstract: Laser is one of the greatest technical discoveries of the 20th century. It is important in basic sciences, but particularly in diagnosis and therapy of various pathologic conditions of human organism. It is electromagnetic radiation, not X-irradiation and, as such, it is not expected to produce new generation of iatrogenic malignancies. Laser falls between infrared and ultraviolet on the spectrum mainly in the visible light spectrum. Properties of laser light are: monochromacity (the same color), coherence (all of the light waves are in phase both spatially and temporally), collimation (all rays are parallel to each other and do not diverge significantly even over long distances). Lasers were first conceived by Einstein in 1917 when he wrote his "Zur Quantum Theorie der Strahlung" (the quantum theory of radiation) which enumerated concepts of stimulated and spontaneous emission and absorption. Drs. Arthur Schawlow and Charles Townes, in 1956, extended lasers into the optical frequency range and Maiman, in 1960, operated the first laser using ruby as the active medium (ruby laser). Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. To understand the acronym, it is necessary to understand the basic physics of the atom. However, if the atom that is in the excited state is struck by another photon of energy before it returns to the ground state, two photons of equal frequency and energy, travelling in the same direction and in perfect spatial and temporal harmony, are produced. This phenomenon is termed stimulated emission of radiation. An external power source hyperexcites the atoms in the laser medium so that the number of atoms possessing upper energy levels exceeds the number of atoms in a power energy level, a condition termed a population inversion. This "pumping system" which imparts additional energy to the atoms may be optical, mechanical, or chemical. These atoms in a hyperexcited state spontaneously emit photons of light. The laser chamber or optical cavity contains an active lasing medium which usually determines the name of each laser. There are four types of lasing material commonly employed. Solid state lasers use a solid matrix material such as a ruby crystal. Gas lasers use a gas or mixture of gases such as helium, argon, and CO2. Dye lasers employ a complex organic dye in liquid solution or suspension such as rhodamine. Semiconductor lasers use two layers of semiconductor substances such as gallium arsenide.
13 citations
TL;DR: In this paper, the electron temperature and density in a plasma flow for low-pressure plasma spraying (LPPS) were performed for the first time, using incoherent Thomson scattering of ruby-laser light.
Abstract: Truly reliable measurements of electron temperature and density in a plasma flow for low-pressure plasma spraying (LPPS) were performed for the first time, using incoherent Thomson scattering of ruby-laser light. The results indicate the characteristic feature of a supersonic nozzle flow, namely, successive appearance of oblique shock-wave heating (~1 eV) and compression (4×1021 m-3), and subsequent cooling (~0.2 eV) and rarefaction (1×1021 m-3).
13 citations
TL;DR: In this article, a double pulse ruby laser was used to obtain interference patterns from a laser produced plasma in helium and the electron density evolution was inferred by Abel inversion, with suitable approximations.
13 citations
TL;DR: In this article, a new technique based on deposition of metallic film at room temperature followed by laser irradiation, for the formation of Ohmic contacts on semiconducting oxides, has been developed.
Abstract: A new technique based on deposition of metallic film at room temperature followed by laser irradiation, for the formation of Ohmic Contacts on semiconducting oxides, has been developed. Aluminum or nickel film about 1 μm thick was deposited on n‐type polycrystalline barium titanate (BaTi03) substrates and irradiated with Q‐switched ruby laser pulses. This technique produces low‐resistance Ohmic contacts which do not age and remain stable over a wide temperature range.
13 citations