
	Where results make sense

Topic: Ultrashort pulses

In the News (Sat 26 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Laser Focus World - Research laboratories harness ultrashort pulses
		The pulse, now with perhaps less than a watt of peak power, is then fed into a medium of high energy density such as Ti:sapphire, which amplifies the pulse significantly—up to the limit of several gigawatts imposed by nonlinearities.
		One of the most exotic applications of ultrashort pulses involves the study of superluminal propagation—velocities that seem to be faster than the speed of light in a vacuum (c).
		Ultrashort pulses also are finding applications in micromachining, optical spectroscopy, and biomedicine, where the short pulse time minimizes heating of adjacent tissues and allows precision microsurgery.
	lfw.pennnet.com /Articles/Article_Display.cfm?Article_ID=80158 (1780 words)

	Laser range meter - Patent 4413905
		A laser range meter utilizing a mode locked laser for transmitting ultrashort pulses toward a target and a receiver for cross correlating the pulses returned from a target with corresponding reference pulses derived from the transmitted pulses is disclosed.
		The laser range meter of claim 1 wherein auxiliary measuring pulses are derived from the transmitted pulses and are radiated toward the target parallel to the primary measuring pulses, and said delayed pulses are returned from the target in response to the auxiliary measuring pulses and are supplied to said second nonlinear element.
		The laser range meter of claim 9 wherein auxiliary measuring pulses are derived from the transmitted pulses and are radiated toward the target parallel to the primary measuring pulses, and pulses returned from the target in response to the auxiliary measuring pulses are supplied to said reference channel as the reference pulses.
	www.freepatentsonline.com /4413905.html (4314 words)

	Ultrashort pulses span wide spectrum - optics.org
		Critically, the team says this is the first time that the two pulses within the filament remain in-phase and retain both their peak intensity and energy over distances far greater than the coherence length.
		The in-phase propagation of the third harmonic together with the fundamental pulse extends the spectral range of the probing pulse further in the UV, allowing the detection of a large number of important biological species.
		Aközbek says the pulse can be collimated or weakly focused by using a longer focal length lens and may be used to probe the atmosphere.
	optics.org /articles/news/8/10/9/1 (462 words)

	Physics Today August 2001
		Measuring powerful femtosecond light pulses is difficult because of the high intensities and ultrashort timescales, but it's straightforward in principle.
		How the pulses change shape with time and distance is measured by a charge-coupled device camera, which records a small fraction of the beam that bounces off a reflective glass plate.
		Laser pulses are already used to map pollutants in the atmosphere.
	www.aip.org /pt/vol-54/iss-8/p17.html (1343 words)

	Scientific Highlights - Molecular Dissociation with Ultrashort Laser Pulses
		The laser pulse duration is shorter than the vibrational period of most molecules, and this simplifies the study of molecular Coulomb explosions.
		Ultrashort laser pulses have also overcome a problem in analytical science.
		A disadvantage of using long (nanosecond) laser pulses is that polyatomic molecules often dissociate into many small fragments which render the parent molecule unidentifiable.
	www.clf.rl.ac.uk /highlights/MolecularDissociation.htm (219 words)

	Temporal and Spectral Measurements of Ultrashort Laser Pulses
		Because ultrashort laser pulses can act as incredibly fast probes, physicists, chemists and biologists now routinely use lasers with durations as low as ~5 femtoseconds to study and control the dynamics of atoms, molecules, and electrons.
		Moreover, ultrashort laser pulses are also beginning to be used for multiphoton microscopy, micromachining and as a potential atomic clocks.
		For any of these uses, and for developing ultrashort pulse lasers, it is vital to be able to accurately measure the temporal and spectral intensity and phase of ultrashort pulses.
	www.spie.org /web/meetings/programs/PW01/courses/SC310.html (304 words)

	Time resolved propagation of ultrashort laser pulses within (Site not responding. Last check: 2007-10-14)
		The internal distribution of irradiance for an impulse vs a 4 ps pulse is specified at different times for various scattering coefficents and scattering phase functions.
		For femtosecond pulses in highly scattering tissues, two-photon reactions are dominated by the initial primary (unscattered, unabsorbed) pulse, and single-photon reactions are dominated by the scattered diffuse irradiance.
		For picosecond pulses in highly scattering tissues, both single-and two-photon reactions are dominated by the scattered irradiance.
	omlc.ogi.edu /pubs/abs/jacques89b.html (140 words)

	Ultrashort pulse - Wikipedia, the free encyclopedia
		Example of spectral phase functions include the case where φ(ω) is a constant, in which case the pulse is called a bandwidth-limited pulse, or where φ(ω) is a quadratic function, in which case the pulse is called a chirped pulse because of the presence of an instantaneous frequency sweep.
		Such a chirp may be acquired as a pulse propagates through materials (like glass) and is due to their dispersion.
		One of them is the pulse compressor, a device that can be used to control the spectral phase of ultrashort pulses.
	en.wikipedia.org /wiki/Ultrashort_pulse (722 words)

	Picosecond sound pulse generation and detection with ultrashort light pulses (via CobWeb/3.1 ... (Site not responding. Last check: 2007-10-14)
		An optical detection pulse is used to monitor the expansion and strain near the surface.
		The actual duration of the acoustic strain pulse is shown by the light blue arrows, corresponding to the raised portion of the optical phase variation caused by surface motion.
		The hand represents the light pulses that generate the acoustic pulses, and the ear the light pulses of different wavelength that detect the acoustic pulses.
	kino-ap.eng.hokudai.ac.jp.cob-web.org:8888 /picoacoustics.html (1103 words)

	Encyclopedia of Laser Physics and Technology - ultrashort pulses, femtosecond, laser
		There is no commonly accepted definition of "ultrashort", but usually this label applies to pulses if their pulse duration is at most a few tens of picoseconds, and often in the range of femtoseconds.
		Note that ultrashort pulses should not be called "ultrafast" – they are not faster (don't have a higher velocity) than longer pulses.
		Ultrashort pulses are usually generated with passively mode-locked lasers, but sometimes also with optical parametric amplifiers (possibly using a supercontinuum as input) or with free electron lasers.
	www.rp-photonics.com /ultrashort_pulses.html (309 words)

	Encyclopedia of Laser Physics and Technology - mode-locked lasers, ultrashort pulses, modelocked, picosecond, ...
		A mode-locked laser is a laser to which the technique of active or passive mode locking is applied, so that a periodic train of ultrashort pulses is emitted.
		As ultrashort pulses have a certain bandwidth, mode-locked lasers for short pulses (particularly in the sub-picosecond region) require a gain medium with a large gain bandwidth.
		The achieved pulse durations are often limited by nonlinearities or by higher-order dispersion rather than by the gain bandwidth.
	www.rp-photonics.com /mode_locked_lasers.html (1393 words)

	Frequency Resolved Optical Gating (FROG) site
		But to become truly useful, any optical technique must go beyond the measurement of mere laser pulses, whose intensity and phase are well-behaved in space, time, and frequency and have fairly high intensity.
		It will need to be able to measure light pulses, whose intensity and phase are not so well-behaved in space, time, and frequency, and which often aren't all that intense.
		For example, we'd like to be able to measure ultrabroadband light pulses from micro-structure optical fiber and ultraweak luminescence from molecules important in biology and human physiology-light pulses whose measurement will lead to new technologies or teach us important things about life, not just how well our laser is aligned.
	www.physics.gatech.edu /gcuo/subIndex.html (300 words)

	Swamp Optics--Ultrashort Laser Pulse Measurement Tutorials
		The very dispersion that is so useful for stretching and compressing pulses also causes pulse-front tilt (as well as spatial chirp) in the pulse if alignment of the stretcher or compressor is not perfect.
		Pulse compressors, which are composed of as many as four dispersive elements, can yield both of these distortions unless aligned perfectly.
		We have discovered that most ultrashort pulses are contaminated with both spatial chirp and pulse-front tilt.
	www.swampoptics.com /tutorials_spatio-temporal.htm (648 words)

	Publications
		Generation of extended pulse trains of minimum duration by passive negative feedback applied to solid state q-switched lasers.
		Pulse rate, average frequency and phase stabilization of a mode-locked pulse train.
		Short pulse ring lasers to create an atomic clock combining a wavelength and time standard in a sensitive gyro.
	www.unm.edu /~jcdiels/html/jcpub.html (2091 words)

	Georgia Tech's Institutional Repository: Measuring broadband, ultraweak, ultrashort pulses (Site not responding. Last check: 2007-10-14)
		The ability to measure and manipulate ultrashort pulses hold the key to probing and understanding these key processes that physicists, engineers, chemists and biologists study today.
		Measuring ultrashort pulses means that we measure both the intensity (which is a function of time) and the phase of the pulse in time.
		Since then, there have been a whole host of pulse measurement techniques that have been invented to measure all sorts of ultrashort pulses.
	hdl.handle.net /1853/7171 (381 words)

	seminar: The Maxwell-Lorentz model for ultrashort optical pulses
		The duration of these ultrashort pulses are of the order 10-100 femtoseconds corresponding to few oscillation periods of the light.
		The traditional envelope approximation based on the nonlinear Schrodinger equation is expected to break down for femtosecond pulses and therefore we go back to first principles solving the Maxwell equations coupled to Lorentz oscillators modelling the induced polarization in silica.
		In the seminar the generation of such pulses will be addressed, which by first sight may seem impossible.
	www2.mat.dtu.dk /events/dk?id=331 (177 words)

	Ultrashort Workshop 2005
		A better understanding of the existing ultrashort pulse laser technology will determine their utility for military and industrial applications.
		Understanding the ultrashort pulse laser materials interaction provides a foundation for determining the applicability of ultrashort pulses for diagnostic, material fabrication, and inspection applications in civilian contexts as well.
		The third annual Ultrashort Pulse Laser Materials Interaction Workshop brought together government, industry, and academic leaders for discussions of basic and applied research and technology efforts and the future of ultrashort lasers for military and other applications.
	www.deps.org /DEPSpages/UshortWksp05.html (441 words)

	Ultrashort pulses help gene therapy (July 2002) - News - PhysicsWeb
		Nanosecond laser pulses from a frequency-tripled Nd:YAG source have also been tried, but according to the researchers, this technique damages the cells beyond repair.
		The femtosecond pulses were focused at the cell membrane using a high-numerical-aperture objective lens.
		The target cells were exposed to the 50-100 mW average power beam for 16 ms during transfection.
	physicsweb.org /article/news/6/7/14 (357 words)

	Ultrashort Pulses (Site not responding. Last check: 2007-10-14)
		This enables generation of intense, short light pulses (with the duration of a few cycles) with precisely reproducible electric and magnetic fields.
		These pulses is a step towards controlling the evolution of strong-field interactions on the time-scale of single light oscillation cycles.
		They are also likely to be important for reproducible attosecond x-ray pulse generation.
	iae.nsk.su /~misha/tuvlg/1999.htm (133 words)

	RP Photonics Consulting - Areas of Competence: Ultrashort Pulses
		pulse generation in mode-locked lasers, including few-cycle femtosecond pulses from Ti:sapphire lasers as well as pulses from diode-pumped bulk lasers, fiber lasers and semiconductor lasers
		Rüdiger Paschotta has an extensive and very deep expertise on ultrashort pulses.
		This is demonstrated by his scientific publications and by the Encyclopedia of Laser Physics and Technology.
	www.rp-photonics.com /topics_pulses.html (177 words)

	Coherence properties of ultrashort optical pulses (Site not responding. Last check: 2007-10-14)
		A non-linear method for the study of the coherence of femtosecond optical pulses is proposed.
		Fringe visibility is enhanced by the non-linear process since the detected signal includes a term with the 4th power of the combination of the fields, instead of the second power in conventional linear detection.
		The authors describe two types of phase modulation-non-linear and linear-that they have observed in the ultrashort pulses generated by a passively mode-locked ring dye laser.
	stacks.iop.org /0150-536X/16/115 (276 words)

	Control of the Carrier-Envelope Phase of Ultrashort Pulses (Site not responding. Last check: 2007-10-14)
		A major focus of JILA Fellow Steve Cundiff's research is the control of the carrier-envelope phase of ultrashort laser pulses.
		The carrier-envelope phase is an evolving phase shift between the peak of an ultrashort pulse's envelope function (superimposed on a continuous carrier wave) and the closest peak of that carrier wave.
		To improve the performance of this process, Cundiff's group is implementing dispersion compensation and optical detection of the timing error between the received signal and the mode-locked laser that functions as a local clock.
	jilawww.colorado.edu /www/research/ultrashort.html (455 words)

	Ultrafast Group - Current Research (via CobWeb/3.1 planetlab-1.cs.princeton.edu) (Site not responding. Last check: 2007-10-14)
		We are currently investigating ways to measure very broadband ultrashort pulses using a spatially-encoded version of the SPIDER technique.
		This technique does not require the creation of two replica of the unknown pulse which can be a concern for very broadband pulses (this can also be an advantage for very weak fields).
		In addition, we are investigating ways to apply the SPIDER technique to the measurement of attosecond pulses in the soft-X-ray region of the spectrum.
	ultrafast.physics.ox.ac.uk.cob-web.org:8888 /proj1.shtml (110 words)

	Time-resolved Photoelectron Spectroscopy using ultrashort EUV Pulses - Molekül- und Oberflächenphysik - ... (Site not responding. Last check: 2007-10-14)
		Using ultrashort pulses in the extreme ultraviolet region (EUV-several tens of eV) rather than the traditional visible and UV range we gain access to the inner structure of an atom's electron shell.
		Following transient changes of photoelectron kinetic energies as function of the phase between the EUV pulse intensity and the visible light-field, isolated EUV pulses of 250 as duration could recently be detected.
		Featuring both high photon energy and short duration such pulses were used to study the inner-shell relaxation of atoms (MNN Auger-decay of krypton).
	www.physik.uni-bielefeld.de /experi/d4/fs (492 words)

	Ultrashort Workshop 2004
		The Ultrashort Pulse Laser Materials Interaction Workshop provides a forum for the presentation of the state-of-the-art ultrashort pulse laser technology and effects; including laser materials interaction and other laser effects.
		A better understanding of the existing ultrashort pulse laser technology will determine their utility for applications within the defense industry.
		This workshop was held immediately after the 20-22 September 2004 Boulder Damage Symposium, an SPIE event.
	www.deps.org /DEPSpages/UshortWksp04.html (529 words)

	Physics and engineering events - Physics Today Event Calendar
		This Conference which joins the ULTRA COST activity ("Laser-matter interactions with ultra-short pulses, high-frequency pulses and ultra-intense pulses.
		Fast particles and intense x-ray radiation from the interactions with ultrashort, ultraintense laser pulses.
		Molecules in the field of ultrashort laser pulses.
	www.physicstoday.org /cal/viewbyuser.jsp?eid=1057 (88 words)

	Amazon.com: Frequency-Resolved Optical Gating: The Measurement of Ultrashort Laser Pulses: Books: Rick Trebino (Site not responding. Last check: 2007-10-14)
		Whether you're an undergrad or an advanced researcher, you'll find easy-to-understand descriptions of all the key ideas behind all the FROG techniques, all the practical details of pulse measurement, and many new directions of research.
		It also contains several additional chapters by the world's leading experts on ultrashort pulse measurement, including a detailed description of measurements of the shortest pulse ever created.
		In addition, iterative algorithms for processing FROG traces are available as well as PowerPoint slides for a class on ultrafast phenomena.
	www.amazon.com /Frequency-Resolved-Optical-Gating-Measurement-Ultrashort/dp/1402070667 (1054 words)

	Phase stabilization of ultrashort optical pulses (Site not responding. Last check: 2007-10-14)
		New methods have recently been developed to measure the carrier-envelope phase evolution of ultrashort optical pulses.
		The resulting ability to stabilize the carrier-envelope phase of the pulse train emitted by a mode-locked laser means that the absolute frequencies in the optical spectrum can be determined, which has had an immediate impact on optical frequency metrology and optical clocks.
		In the time domain, this establishes the basis for controlling and tailoring the electric field of ultrashort pulses, which will affect applications in extreme nonlinear optics and coherent control.
	stacks.iop.org /0022-3727/35/R43 (270 words)

	Swamp Optics--Ultrashort Laser Pulse Measurement Publications
		Frequency-Resolved Optical Gating: The Measurement of Ultrashort Laser Pulses, by Swamp Optics' own Rick Trebino, is available from Kluwer Academic Publishers and Amazon.com.
		Measurement of the intensity and phase of attojoule femtosecond light pulses using Optical-Parametric-Amplification Cross-Correlation Frequency-Resolved Optical Gating [PDF]
		Measuring spatial chirp in ultrashort pulses using single-shot Frequency-Resolved Optical Gating
	www.swampoptics.com /news_publications.htm (328 words)

Try your search on: Qwika (all wikis)