Theodor W. Hänsch

Cavity-enhanced dual-comb spectroscopy (2009)

Bernhardt, Birgitta, Ozawa, Akira, Jacquet, Patrick, Jacquey, Marion, Kobayashi, Yohei, Udem, Thomas, ...

The sensitivity of molecular fingerprinting is dramatically improved when placing the absorbing sample in a high-finesse optical cavity, thanks to the large increase of the effective path-length. As...

Laser frequency combs for astronomical observations (2008)

Steinmetz, Tilo, Wilken, Tobias, Araujo-Hauck, Constanza, Holzwarth, Ronald, Hänsch, Theodor W., Pasquini, Luca, ...

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require...

High harmonic frequency combs for high resolution spectroscopy (2008)

Ozawa, Akira, Rauschenberger, Jens, Gohle, Christoph, Herrmann, Maximilian, Walker, David R., Pervak, Volodymyr, ...

We generated a series of harmonics in a xenon gas jet inside a cavity seeded by pulses from a Ti:sapphire mode-locked laser with a repetition rate of 10.8 MHz. Harmonics up to 19th order at 43 nm...

Laser frequency combs for astronomical observations (2008)

Steinmetz, Tilo, Wilken, Tobias, Araujo-Hauck, Constanza, Holzwarth, Ronald, Hänsch, Theodor W., Pasquini, Luca, ...

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require...

Laser frequency combs for astronomical observations (2008)

Steinmetz, Tilo, Wilken, Tobias, Araujo-Hauck, Constanza, Holzwarth, Ronald, Hänsch, Theodor W., Pasquini, Luca, ...

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require...

Cavity Enhanced Optical Vernier Spectroscopy, Broad Band, High Resolution, High Sensitivity (2007)

Gohle, Christoph, Stein, Björn, Schliesser, Albert, Udem, Thomas, Hänsch, Theodor W.

A femtosecond frequency comb provides a vast number of equidistantly spaced narrow band laser modes that can be simultaneously tuned and frequency calibrated with 15 digits accuracy. Our Vernier...

Bose-Einstein condensate coupled to a nanomechanical resonator on an atom chip (2007)

Treutlein, Philipp, Hunger, David, Camerer, Stephan, Hänsch, Theodor W., Reichel, Jakob

We theoretically study the coupling of Bose-Einstein condensed atoms to the mechanical oscillations of a nanoscale cantilever with a magnetic tip. This is an experimentally viable hybrid quantum...

Microwave potentials and optimal control for robust quantum gates on an atom chip (2006)

Treutlein, Philipp, Hänsch, Theodor W., Reichel, Jakob, Negretti, Antonio, Cirone, Markus A., Calarco, Tommaso

We propose a two-qubit collisional phase gate that can be implemented with available atom chip technology, and present a detailed theoretical analysis of its performance. The gate is based on earlier...

Quantum Information Processing in Optical Lattices and Magnetic Microtraps (2006)

Treutlein, Philipp, Steinmetz, Tilo, Colombe, Yves, Lev, Benjamin, Hommelhoff, Peter, Reichel, Jakob, ...

We review our experiments on quantum information processing with neutral atoms in optical lattices and magnetic microtraps. Atoms in an optical lattice in the Mott insulator regime serve as a large...

Schneller Zählen als das Licht (2006)

Gohle, Christoph, Herrmann, Maximilian, Udem, Thomas, Hänsch, Theodor W.

The frequency comb technology that was awarded the Noble Prize of Physics enables frequency measurements of highest accuracy and the development of high-precision “optical clocks”. New...

Photoionization broadening of the 1S-2S transition in a beam of atomic hydrogen (2006)

Kolachevsky, Nikolai, Haas, Martin, Jentschura, Ulrich David, Herrmann, Maximilian, Fendel, Peter, Fischer, Marc, ...

We consider the excitation dynamics of the two-photon 1S-2S transition in a beam of atomic hydrogen by 243 nm laser radiation. Specifically, we study the impact of ionization damping on the...

Atomic Interferometer with Amplitude Gratings of Light and its Applications to Atom Based Tests of the Equivalence Principle (2004)

Fray, Sebastian, Diez, Cristina Alvarez, Hänsch, Theodor W., Weitz, Martin

We have developed a matter wave interferometer based on the diffraction of atoms from effective absorption gratings of light. In a setup with cold rubidium atoms in an atomic fountain the...

New Limits on the Drift of Fundamental Constants from Laboratory Measurements (2004)

Fischer,M., Kolachevsky,Nikolai, Zimmermann,Marcus, Holzwarth,Ronald, Udem,Thomas, Hänsch,Theodor W., ...

We have remeasured the absolute 1S-2S transition frequency H in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of (–29±57) Hz for the...

Holographic recording of laser-induced plasma (2004)

Centurion, Martin, Pu, Ye, Liu, Zhiwen, Psaltis, Demetri, Hänsch, Theodor W.

We report on a holographic probing technique that allows for measurement of free-electron distribution with fine spatial detail. Plasma is generated by focusing a femtosecond pulse in air. We also...

New Limits on the Drift of Fundamental Constants from Laboratory Measurements (2004)

Fischer, M., Kolachevsky, Nikolai, Zimmermann, Marcus, Holzwarth, Ronald, Udem, Thomas, Hänsch, Theodor W., ...

We have remeasured the absolute 1S-2S transition frequency H in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of (–29±57) Hz for the...

New Limits on the Drift of Fundamental Constants from Laboratory Measurements (2004)

Fischer, M., Kolachevsky, Nikolai, Zimmermann, Marcus, Holzwarth, Ronald, Udem, Thomas, Hänsch, Theodor W., ...

We have remeasured the absolute 1S-2S transition frequency H in atomic hydrogen. A comparison with the result of the previous measurement performed in 1999 sets a limit of (–29±57) Hz for the...

Coherence in Microchip Traps (2003)

Treutlein, Philipp, Hommelhoff, Peter, Steinmetz, Tilo, Hänsch, Theodor W., Reichel, Jakob

We report the coherent manipulation of internal states of neutral atoms in a magnetic microchip trap. Coherence lifetimes exceeding 1 s are observed with atoms at distances of $5-130 \mu$m from the...

Entanglement interferometry for precision measurement of atomic scattering properties (2003)

Widera, Artur, Mandel, Olaf, Greiner, Markus, Kreim, Susanne, Hänsch, Theodor W., Bloch, Immanuel

We report on a two-particle matter wave interferometer realized with pairs of trapped 87Rb atoms. Each pair of atoms is confined at a single site of an optical lattice potential. The interferometer...

Collapse and revival of the matter wave field of a Bose- Einstein condensate (2002)

Greiner,Markus, Mandel,Olaf, Hänsch,Theodor W., Bloch,Immanuel

A Bose-Einstein condensate represents the most 'classical' form of a matter wave, just as an optical laser emits the most classical form of an electromagnetic wave. Nevertheless, the matter wave...

Growth of Bose-Einstein condensates from thermal vapor (2002)

Köhl,Michael, Davis,M. J., Gardiner,C. W., Hänsch,Theodor W., Esslinger,Tilman

We report on a quantitative study of the growth process of 87Rb Bose-Einstein condensates. By continuous evaporative cooling we directly control the thermal cloud from which the condensate grows. We...

Continuous detection of an atom laser beam (2002)

Köhl,Michael, Hänsch,Theodor W., Esslinger,Tilman

We have demonstrated a detection scheme for atom laser beams that allows for a continuous measurement of the atom density and readout of the data in real time. The atoms in the atom laser beam are...

Mott-Isolator-Zustand: Perfekte Ordnung am Nullpunkt (2002)

Greiner,Markus, Hänsch,Theodor W., Bloch,Immanuel

Nirgends wird die Welleneigenschaft von Materie so deutlich wie in einem Bose-Einstein-Kondensat. Dennoch ist es möglich, ein wellenartiges Bose-Einstein-Kondensat in ein geordnetes Teilchengitter...

Continuous detection of an atom laser beam (2002)

Köhl, Michael, Hänsch, Theodor W., Esslinger, Tilman

We have demonstrated a detection scheme for atom laser beams that allows for a continuous measurement of the atom density and readout of the data in real time. The atoms in the atom laser beam are...

Growth of Bose-Einstein condensates from thermal vapor (2002)

Köhl, Michael, Davis, M. J., Gardiner, C. W., Hänsch, Theodor W., Esslinger, Tilman

We report on a quantitative study of the growth process of 87Rb Bose-Einstein condensates. By continuous evaporative cooling we directly control the thermal cloud from which the condensate grows. We...

Collapse and revival of the matter wave field of a Bose- Einstein condensate (2002)

Greiner, Markus, Mandel, Olaf, Hänsch, Theodor W., Bloch, Immanuel

A Bose-Einstein condensate represents the most 'classical' form of a matter wave, just as an optical laser emits the most classical form of an electromagnetic wave. Nevertheless, the matter wave...

Mott-Isolator-Zustand: Perfekte Ordnung am Nullpunkt (2002)

Greiner, Markus, Hänsch, Theodor W., Bloch, Immanuel

Nirgends wird die Welleneigenschaft von Materie so deutlich wie in einem Bose-Einstein-Kondensat. Dennoch ist es möglich, ein wellenartiges Bose-Einstein-Kondensat in ein geordnetes Teilchengitter...

Continuous detection of an atom laser beam (2001)

Köhl, Michael, Hänsch, Theodor W., Esslinger, Tilman

We have demonstrated a detection scheme for atom laser beams that allows for a continuous measurement of the atom density and readout of the data in real-time. The atoms in the atom laser beam are...

Measuring the temporal coherence of an atom laser beam (2001)

Köhl, Michael, Hänsch, Theodor W., Esslinger, Tilman

We report on the measurement of the temporal coherence of an atom laser beam extracted from a $^{87}$Rb Bose-Einstein condensate. Reflecting the beam from a potential barrier creates a standing...

Optics with an Atom Laser Beam (2000)

Bloch, Immanuel, Köhl, Michael, Greiner, Markus, Hänsch, Theodor W., Esslinger, Tilman

We report on the atom optical manipulation of an atom laser beam. Reflection, focusing and its storage in a resonator are demonstrated. Precise and versatile mechanical control over an atom laser...