Producing ultrashort high-energy laser pulses with repetition rates of over a million per second present laser engineers with severe challenges. For this purpose, LAP physicists of the Ultrafast Optics (UFO) group with the chair of Experimental Physics (Laser Physics) of LMU focus long infrared laser pulses into a crystal to produce so called white light. This can be done with various types of crystals, such as the Yttrium aluminium garnet crystal. This white light is then increased in energy with long infrared laser pulses and then compressed in time with special mirrors to flashes of light, now lasting just very few femtoseconds. Courtesy of Thorsten Naeser.

Producing ultrashort high-energy laser pulses with repetition rates of over a million per second present laser engineers with severe challenges. For this purpose, LAP physicists of the Ultrafast Optics (UFO) group with the chair of Experimental Physics (Laser Physics) of LMU focus long infrared laser pulses into a crystal to produce so called white light. This can be done with various types of crystals, such as the blue-gleaming Yttrium vanadate crystal. This white light is then increased in energy with long infrared laser pulses and then compressed in time with special mirrors to flashes of light, now lasting just very few femtoseconds. Courtesy of Thorsten Naeser.

For the first time ever, a European research team has managed to use attosecond laser pulses to observe the motion electrons in molecules. This report is published in the journal Nature, issue June 10th. Courtesy of Christian Hackenberger.

The photoemission of electrons by an attosecond light pulse (blue beam) is time resolved by controlling the electron motion with an ultrashort visible laser pulse (shown as red beam). This attosecond streaking uncovers that electrons from different atomic orbitals are released with a delay comparable to the atomic unit of time. Courtesy of Thorsten Naeser and Christian Hackenberger.

In future physicists at LAP are to produce particle beams in black chambers like that of Rainer Hörlein. For this purpose they use ultrashort high-intensity laser pulses lasting about 50 femtoseconds. The laser pulses are directed at diamond –like carbon foils just nanometres thick. The photons of the laser pulses exert pressure on the foil and eject ions, i.e. charged atoms. The pressure of light can attain up to ten gigabar (one billion bar). For comparison: On earth the prevailing pressure is one bar. The ions ejected are thus accelerated to ten per cent o the velocity of light. These ions are then applied to samples of tissue cells. The scientists now want to determine how the laser-accelerated ions have to be dosed in order to destroy cancer cells in tissue. This would afford a possibility of combating tumors by means of laser light. The scientists are thus on the threshold to developing efficient and, primarily, controlled acceleration of ions with laser light. The aim is to use lasers in future to provide ion radiotherapy with facilities that are compact and hence available to smaller hospitals. Courtesy of Thorsten Naeser.

Researchers from LMU and MPQ (group of Prof. Kleineberg) are investigating the ultrafast dynamics of collective electron motion (commonly referred to as “localized surface plasmons”) and induced localized optical fields in various kinds of metallic nanostructures, which take place on a nanometer spatial scale as well as on a sub-fs temporal scale. The results may help to understand and develop ultrafast electronics in the future based on localized and propagating surface plasmons rather than on drifting electrons. Courtesy of Thorsten Naeser.

View into the experimental chamber of the attosecond beamline AS2: Atomic gas streams from a nozzle into the interaction volume where attosecond XUV pulses and few-cycle laser pulses are employed for pump probe experiments. Photoelectrons are detected by a time of flight detector (TOF) mounted from the top, the ionized atoms are investigated by a mass spectrometer (reflectron) oriented horizontally. Courtesy of Thorsten Naeser.

A nozzle emits a rare gas that converts laser pulses, coming from the right, into attosecond light flashes. Courtesy of Thorsten Naeser.

The scientists Matthias Kling (l) and Sergey Zherebtsov are discussing the setup of the beamline AS5. Courtesy of Thorsten Naeser.

Ultraviolet photons are required for photoemission of femtosecond electron pulses. These have a 50,000-fold shorter wavelength than the blue light in this picture, and are our tool to visualize atoms and their motion in all four dimensions of space and time. See www.ultrafast-electron-imaging.com for details. Courtesy of Thorsten Naeser.

The slender stainless-stell nozzles in a vacuum chamber of the AS4b attosecond beamline extend like stalactites into the centre of the experimental setup. From the right-hand edge of the photo the physicists focus invisible infrared light pulses lasting about 3.5 femtoseconds exactly on the centre of the left-hand gas nozzle, which emits neon gas whose atoms are exited by the infrared light pulses, thus giving them a reddish fluorescence. The right-hand gas nozzle, on the other hand, emits the argon, which emits a blue fluorescence, likewise due to the excitation caused by the infrared light. In this excitation process the rare-gas atoms produce light pulses both in the ultraviolet (UV wavelength about 250 nanometers) and in the extreme ultraviolet spectrum of the light (XUV, wavelength about 8 nanometers). Courtesy of Thorsten Naeser.

Mirror production at the clean room of the Munich Centre for Advanced Photonics (MAP). Courtesy of Thorsten Naeser.

Image of the field oscillations in a few-cycle pulse of red laser light sampled with 250-attosecond x-ray pulses. Courtesy of Dr. Eleftherios Goulielmakis.

The world's first 5-femtosecond multi-Gigawatt Ti:sapphire laser system. Photonics Institute, Vienna University of Technology, 1997.

The world's first laboratory source of coherent X-rays in the water window (270-550 eV; 2.3-4.4 nm) produced by irradiating helium atoms with 0.3-millijoule, 5-femtosecond near-infrared (750-nm) pulses from a Ti:sapphire laser. The purple fluorescence emission originates from ionized high-density helium gas streaming out of a thin metal tube through holes bored by the focused laser beam. The X-ray harmonics are emitted coherently in a well collimated beam collinear to the laser beam, which propagates along the axis of the purple emission. Photonics Institute, Vienna University of Technology, 1997. Photo courtesy of Dr. Gabriel Tempea.

The world's first source of light pulses shorter than one femtosecond, generated by exposing neon atoms to 0.3-millijoule, 5-femtosecond, near-infared laser pulses. The fluorescence emission originates from ionizing neon atoms streaming from the interaction volume (thin metal tube). Photonics Institute, Vienna University of Technology, courtesy of Dr. Gabriel Tempea.
The movie shows the vacuum beamline used for generating and measuring the sub-femtosecond pulses along with the 5-fs laser system constituting the pump source, courtesy of Dr. Matthias Schnürer.

The world's first coherent source of kiloelectronvolt radiation (wavelength ~ 1 nm). The coherent X-rays are produced by irradiating helium atoms with 1-millijoule, 5-femtosecond near-infrared (750-nm) pulses from a Ti:sapphire laser. The purple fluorescence emission originates from ionized high-density helium gas streaming out of a thin metal tube through holes bored by the focused laser beam. The X-ray harmonics are emitted coherently in a well collimated beam collinear to the laser beam, which propagates along the axis of the purple emission. Photonics Institute, Vienna University of Technology, 2003. Courtesy of Dr. Jozsef Seres.

The world's first source of intense waveform-controlled laser light generates 0.3-mJ, 5-fs laser pulses in the near infrared (wavelength ~ 750 nm) with a controlled evolution of the several oscillations of the electric and magnetic fields.

A sequence of ultrabroad-band chirped multilayer dielectric mirrors compress pulses of visible laser light for the first time to a duration below 4 femtoseconds. The spectrum of the radiation extends from less than 550 nm to more than 1100 nm. It is produced by self-phase modulation in a short piece (~ 4 mm) of single-mode optical fiber fed by a sub-10-fs Ti:sapphire oscillator. Photonics Institute, Vienna University of Technology, 2003. Courtesy of Dr. Alexander Apolonsky.

First real-time observation of the motion of electrons deep in the interior of an excited atom. Copyright: The New York Times.

First-generation attosecond beamline (AS-0) used for the generation and measurement of sub-femtosecond pulses. The system was originally developed at the Photonics Institute of the Vienna University of Technology (1999-2001) and rebuilt at the Max Planck Institute of Quantum Optics in 2003-2004.

Enabling technology for producing intense few-cycle laser pulses: broadband visible-infrared laser pulses are compressed to 5 femtoseconds upon being reflected off several specially-designed chirped multilayer dielectric mirrors. Separation of the individual frequency components of the broadband radiation reveals that colours all the way from the blue to the infrared with precise timing (ensured by the chirped mirrors) are required to create a sub-5-fs pulse.

Proprietary chirped-pulse oscillator (CPO) technology allows the production of microjoule-scale sub-100-fs pulses at a repetition rate of several Megahertz from Ti:sapphire oscillators. Femtosecond CPO sources permit nanometre-precision machining of dielectrics both on the surface and within the bulk.