|
Fritz Peter Schäfer
Fritz Peter Schäfer (15 January 1931 – 25 April 2011) was a German physicist, born in Hersfeld, Hesse-Nassau. He is the co-inventor of the organic dye laser Organic lasers use an organic (carbon based) material as the gain medium. The first organic laser was the liquid dye laser. These lasers use laser dye solutions as their gain media. Organic lasers are inherently tunable and when configured as .... His book, ''Dye Lasers'', is considered a classic in the field of tunable lasers. In this book the chapter written by Schäfer gives an ample and insightful exposition on organic laser dye molecules in addition to a description on the physics of telescopic, and multiple-prism, tunable narrow-linewidth laser oscillators. In their original experiment Schäfer and colleagues employed a ruby laser to optically excite various infrared organic dyes. These dyes emitted laser radiation in the 731-835 nm range. Schäfer ''et al.'' achieved high power outputs at a bandwidth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bad Hersfeld
The festival and spa town of Bad Hersfeld (''Bad'' is "spa" in German; the Old High German name of the city was ''Herolfisfeld'') is the district seat of the Hersfeld-Rotenburg district in northeastern Hesse, Germany, roughly 50 km southeast of Kassel. Bad Hersfeld is known countrywide above all for the ''Bad Hersfelder Festspiele'' (festival), which have taken place each year since 1951 at the monastery ruins. These themselves are said to be Europe's biggest Romanesque church ruin. In 1967, the town hosted the seventh ''Hessentag'' state festival. Geography Location The town lies in the Hersfeld Basin formed here by the forks of the Fulda and the Haune. The inner town lies on the Fulda's left bank. Furthermore, the Geisbach and the Solz empty into the Fulda in the municipal area. In the southwest lie the Vogelsberg Mountains, in the northwest the Knüll and in the northeast the Seulingswald (ranges, the latter visible in the background of this image). The town's lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hesse-Nassau
The Province of Hesse-Nassau () was a province of the Kingdom of Prussia from 1868 to 1918, then a province of the Free State of Prussia until 1944. Hesse-Nassau was created as a consequence of the Austro-Prussian War of 1866 by combining the previously independent Hesse-Kassel (or Hesse-Cassel), the Duchy of Nassau, the Free City of Frankfurt, areas gained from the Kingdom of Bavaria, and areas gained from the Grand Duchy of Hesse (including part of the former Landgraviate of Hesse-Homburg from Hesse-Darmstadt). These regions were combined to form the province Hesse-Nassau in 1868 with its capital in Kassel and redivided into two administrative regions: Kassel and Wiesbaden. The largest part of the province surrounded the province of Upper Hesse in the Grand Duchy of Hesse (People's State of Hesse from 1918). On 1 April 1929, the Free State of Waldeck became a part of Hesse-Nassau after a popular vote, becoming part of the Kassel administrative region. In 1935, the Nazi govern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dye Laser
A dye laser is a laser that uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths, often spanning 50 to 100 nanometers or more. The wide bandwidth makes them particularly suitable for tunable lasers and pulsed lasers. The dye rhodamine 6G, for example, can be tuned from 635 nm (orangish-red) to 560 nm (greenish-yellow), and produce pulses as short as 16 femtoseconds. Moreover, the dye can be replaced by another type in order to generate an even broader range of wavelengths with the same laser, from the near-infrared to the near-ultraviolet, although this usually requires replacing other optical components in the laser as well, such as dielectric mirrors or pump lasers. Dye lasers were independently discovered by P. P. Sorokin and F. P. Schäfer (and colleagues) in 1966. In addition to the usual liquid state, dye lasers are also availa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunable Laser
A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range. There are many types and categories of tunable lasers. They exist in the gas, liquid, and solid state. Among the types of tunable lasers are excimer lasers, gas lasers (such as CO2 and He-Ne lasers), dye lasers (liquid and solid state), transition metal solid-state lasers, semiconductor crystal and diode lasers, and free electron lasers. Tunable lasers find applications in spectroscopy, photochemistry, atomic vapor laser isotope separation, and optical communications. Types of tunability Single line tuning Since no real laser is truly monochromatic, all lasers can emit light over some range of frequencies, known as the linewidth of the laser transition. In most lasers, this linewidth is quite narrow (for example, the nm wave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruby Laser
A ruby laser is a solid-state laser that uses a synthetic ruby crystal as its gain medium. The first working laser was a ruby laser made by Theodore H. "Ted" Maiman at Hughes Research Laboratories on May 16, 1960. Ruby lasers produce pulses of coherent visible light at a wavelength of 694.3 nm, which is a deep red color. Typical ruby laser pulse lengths are on the order of a millisecond. Design A ruby laser most often consists of a ruby rod that must be pumped with very high energy, usually from a flashtube, to achieve a population inversion. The rod is often placed between two mirrors, forming an optical cavity, which oscillate the light produced by the ruby's fluorescence, causing stimulated emission. Ruby is one of the few solid state lasers that produce light in the visible range of the spectrum, lasing at 694.3 nanometers, in a deep red color, with a very narrow linewidth of 0.53 nm.''Principles of Lasers'' By Orazio Svelto – Plenum Press 1976 Page 367–370. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Dye
Laser dyes are dyes used as laser medium in a dye laser. Laser dyes include the coumarins and the rhodamines. Coumarin dyes emit in the green region of the spectrum, whereas rhodamine dyes are used for emission in the yellow-red. The color emitted by the laser dyes depend upon the surrounding medium i.e.the medium in which they are dissolved. However, there are dozens of laser dyes that can be used to span continuously the emission spectrum from the near ultraviolet to the near infrared.F. J. Duarte, ''Tunable Laser Optics'' (Elsevier-Academic, New York, 2003) Appendix of Laser Dyes (includes more than 50 laser dyes) Laser dyes are also used to dope solid-state matrices, such as poly(methyl methacrylate) (PMMA), and ORMOSILs, to provide gain media for solid state dye lasers. Partial list of laser dyes *Coumarins (in various nomenclatures such as Coumarin 480, 490, 504, 521, 504T, 521T) *Fluorescein * polyphenyl ("polyphenyl 1") S. C. Guggenheimer, A. B. Petersen"High P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Planck Institute For Biophysical Chemistry
The Max Planck Institute for Biophysical Chemistry (german: Max-Planck-Institut für biophysikalische Chemie), also known as the Karl-Friedrich Bonhoeffer Institute (german: Karl-Friedrich-Bonhoeffer-Institut), was a research institute of the Max Planck Society, located in Göttingen, Germany. On January 1, 2022, the institute merged with the Max Planck Institute for Experimental Medicine in Göttingen to form the Max Planck Institute for Multidisciplinary Sciences. This was the only Max Planck Institute (MPI) which combined the three classical scientific disciplines – biology, physics and chemistry. Founded in 1971, its initial focus was on problems in physics in chemistry. It had undergone a continuous evolution manifested by an expanding range of core subjects and work areas such as neurobiology, biochemistry, and molecular biology. At the time of merger, 850 people worked at the institute, about half of them scientists. Four researchers working at the institute (Stefan Hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Göttingen
Göttingen (, , ; nds, Chöttingen) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. At the end of 2019, the population was 118,911. General information The origins of Göttingen lay in a village called ''Gutingi, ''first mentioned in a document in 953 AD. The city was founded northwest of this village, between 1150 and 1200 AD, and adopted its name. In Middle Ages, medieval times the city was a member of the Hanseatic League and hence a wealthy town. Today, Göttingen is famous for its old university (''Georgia Augusta'', or University of Göttingen, "Georg-August-Universität"), which was founded in 1734 (first classes in 1737) and became the most visited university of Europe. In 1837, seven professors protested against the absolute sovereignty of the House of Hanover, kings of Kingdom of Hanover, Hanover; they lost their positions, but be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1931 Births
Events January * January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics. * January 4 – German pilot Elly Beinhorn begins her flight to Africa. * January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia. * January 25 – Mohandas Gandhi is again released from imprisonment in India. * January 27 – Pierre Laval forms a government in France. February * February 4 – Soviet leader Joseph Stalin gives a speech calling for rapid industrialization, arguing that only strong industrialized countries will win wars, while "weak" nations are "beaten". Stalin states: "We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it, or they will crush us." The first five-year plan in the Soviet Union is intensified, for the industrialization and collectivization of agriculture. * February 10 †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2011 Deaths
This is a list of deaths of notable people, organised by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked here. 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 See also * Lists of deaths by day The following pages, corresponding to the Gregorian calendar, list the historical events, births, deaths, and holidays and observances of the specified day of the year: Footnotes See also * Leap year * List of calendars * List of non-standard ... * Deaths by year {{DEFAULTSORT:deaths by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From Bad Hersfeld
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form " people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From Hesse-Nassau
A person (plural, : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal obligation, legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_1938.jpg "Click for more on -> People From Bad Hersfeld")