A5055113260- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Spectroscopy and Laser Applications
- Mass Spectrometry Techniques and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Quantum Chemical Studies
- Solid State Laser Technologies
- Photonic and Optical Devices
- Advanced Frequency and Time Standards
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Cold Atom Physics and Bose-Einstein Condensates
- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Radio Frequency Integrated Circuit Design
- Atomic and Subatomic Physics Research
- Laser-Plasma Interactions and Diagnostics
- Analytical Chemistry and Sensors
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Silicon Carbide Semiconductor Technologies
- Noncommutative and Quantum Gravity Theories
- Advancements in PLL and VCO Technologies
- Scientific Measurement and Uncertainty Evaluation
- Radiation Effects in Electronics
Graz University of Technology
2021-2023
Technical University of Munich
2018-2019
Friedrich Schiller University Jena
2018-2019
Max Planck Institute of Quantum Optics
2006-2015
Lawrence Berkeley National Laboratory
2014-2015
University of California, Berkeley
2014-2015
Ludwig-Maximilians-Universität München
2012-2014
Max Planck Society
2006-2012
Johannes Gutenberg University Mainz
2009
Max Planck Institute for Nuclear Physics
2009
We have measured the 1S - 2S transition frequency in atomic hydrogen via two photon spectroscopy on a 5.8 K beam. obtain $f_{1S-2S} = 2 466 061 413 187 035 (10)$ Hz for hyperfine centroid. This is fractional uncertainty of $4.2\times 10^{-15}$ improving previous measure- ment by our own group [M. Fischer et al., Phys. Rev. Lett. 92, 230802 (2004)] factor 3.3. The probe laser was phase coherently linked to mobile cesium fountain clock FOM comb.
The highly energetic photons of ultraviolet light drive electronic and rovibronic transitions in all molecular species. This radiation is thus a prime tool for strongly selective spectroscopic fingerprinting real-time environmental monitoring if broad spectral coverage, short acquisition times, high resolution are achieved–requirements that mutual competition traditional applications. As an approach with intrinsic potency three aspects, here we introduce dual comb spectroscopy using two...
A passive optical resonator is used to enhance the power of a pulsed 78MHz repetition rate Yb laser providing 200fs pulses. We find limitations relating achievable time-averaged and peak power, which we distinguish by varying duration input An intracavity average 18kW generated with close Fourier-limited pulses 10W power. Beyond this level, intensity-related effects lead instabilities, can be removed chirping seed By extending pulse in way 2ps, could obtain 72kW circulating 50W
We report on the first (to our knowledge) demonstration of nonlinear dual-frequency-comb spectroscopy. In multi-heterodyne femtosecond Raman-induced Kerr-effect spectroscopy, Raman gain resulting from coherent excitation molecular vibrations by a spectrally narrow pump is imprinted onto laser frequency comb probe spectrum. The birefringence signal induced interaction these beams and sample heterodyned against local oscillator with repetition slightly different that probe. Such time-domain...
Electronic wavepackets composed of multiple bound excited states atomic neon lying between 19.6 and 21.5 eV are launched using an isolated attosecond pulse. Individual quantum beats the wavepacket detected by perturbing induced polarization medium with a time-delayed few-femtosecond near-infrared (NIR) pulse via coupling individual to neighboring levels. All initially monitored simultaneously in transient absorption spectrum, revealing Lorentzian Fano lineshape spectral changes as well...
The decay of highly excited states xenon after absorption extreme ultraviolet light is directly tracked via attosecond transient spectroscopy using a time-delayed near-infrared perturbing pulse. lifetimes the autoionizing 5$s$5${p}^{6}$6$p$ and 5$s$5${p}^{6}$7$p$ channels are determined to be (21.9 \ifmmode\pm\else\textpm\fi{} 1.3) fs (48.4 5.0) fs, respectively. observed values support lifetime estimates obtained by traditional linewidth measurements. experiment additionally obtains...
We apply a recently demonstrated method for precision spectroscopy on strong transitions in trapped ions to measure both fine-structure components of the $3s\text{\ensuremath{-}}3p$ transition ${^{24}\text{M}\text{g}}^{+}$ and ${^{26}\text{M}\text{g}}^{+}$. deduce absolute frequency reference data frequencies, isotope shifts, splittings that particular are useful comparison with quasar absorption spectra, which test possible space-time variations constant. The measurement accuracy improves...
Ultrafast spectroscopy with attosecond resolution has enabled the real time observation of ultrafast electron dynamics in atoms, molecules and solids. These experiments employ pulses or pulse trains explore dynamical processes a pump-probe scheme that is selectively sensitive to electronic state matter via photoelectron XUV absorption includes changes ionic detected photo-ion mass spectrometry. Here, we demonstrate how implementation combined enables tracking complex multidimensional...
We introduce a portable dual-comb spectrometer operating in the visible spectral region for atmospheric monitoring of NO 2 , pollution gas major importance. Dual-comb spectroscopy, combining key advantages fast, broadband and accurate measurements, has been established infrared as method investigation gases with kilometer-scale absorption path lengths. With presented centered at 517 nm, we make use strong cross section this region. In combination multi-pass approach through atmosphere,...
We demonstrate sub-Doppler laser spectroscopy with a beam of ${^{7}\text{L}\text{i}}^{+}$ ions stored at 33.8% the speed light in experimental storage ring GSI. Using two lasers, one copropagating and other counterpropagating, respect to ion beam, fluorescence line is observed via optical-optical double-resonance on $\ensuremath{\Lambda}$-type level configuration. A linewidth $\ensuremath{\approx}114\text{ }\text{MHz}$ found, which 12 times narrower than Doppler broadening due momentum...
Dual Comb Spectroscopy proved its versatile capabilities in molecular fingerprinting different spectral regions, but not yet the ultraviolet (UV). Unlocking this window would expand to electronic energy structure of matter. This will access prime triggers photochemical reactions with unprecedented resolution. In research article, we discuss milestones marking way first UV dual comb spectrometer. We present experimental and simulated studies towards spectroscopy, directly applied planned...
Michelson-less Fourier spectra, comprising 500,000,000 spectral elements spanning 1 nm with 2.3 kHz (7.7 10−8 cm−1) resolution, are recorded within 6s. Moving mirror of equivalent interferometers should cover 130 km at 78,000 km/hour velocity.
We present the first (to our best knowledge) femtosecond enhancement cavity in visible wavelength range for ultraviolet frequency comb generation. The is seeded at 518 nm by a frequency-doubled Yb fiber laser and operates peak intensity of 1.2×10(13) W/cm(2). High harmonics up to ninth order (~57 nm) are generated an intracavity xenon gas jet. Intracavity high harmonic powers several milliwatts third microwatts fifth prove potential "green cavity" as efficient source future spectroscopic...
We present an optical parametric chirped pulse amplifier (OPCPA) delivering CEP-stable ultrashort pulses with 7 fs, high energies of more than 1.8 mJ and average output power exceeding 10 W at a repetition rate 6 kHz. The system is pumped by picosecond regenerative thin-disk exhibits excellent long-term stability. In proof-of-principle experiment, harmonic generation demonstrated in neon up to the 61st order.
Attosecond transient absorption spectra near the energies of autoionizing states are analyzed in terms photon coupling mechanisms to other states. In a recent experiment, autoionization lifetimes highly excited xenon were determined and compared simple expression based on model how quantum coherence determines decay metastable state spectrum. Here it is shown that this procedure for extracting more general can be used cases involving either resonant or nonresonant attosecond-probed continua...
An optical frequency distribution system has been developed that continuously delivers a stable of 268 THz (corresponding to wavelength 1118 nm) different experiments in our institute. For purpose, continuous wave (cw) fiber laser stabilized onto comb and distributed across the building by use network. While light propagates through fiber, acoustic thermal effects counteract against stability accuracy system. However, employing proper stabilization methods 2 x 10(-13) tau(-1/2) is achieved,...
Photodissociation of ozone following absorption biologically harmful solar ultraviolet radiation is the key mechanism for life protecting properties atmospheric layer. Even though photolysis described successfully by post-Hartree-Fock theory, it has evaded direct experimental access so far, due to unavailability intense ultrashort deep sources. The rapidity with predicted values a few tens femtoseconds renders both pump and probe pulses indispensable capture this manifestation ultrafast...
A self aligned complementary GaAs (CGaAs) technology has been developed for low-power, high-speed digital and mixed-mode applications. Previous work described the low voltage (0.9 to 1.5 V) power applications portable products. Complementary circuits have demonstrated speed performance of 0.01 /spl mu/W/MHz/gate at 0.9 V. This paper will describe our extensions this process provide even higher performance, expense slightly static dissipation. The allow flexibility tune different sections...
Abstract The highly energetic photons of ultraviolet light drive electronic, vibrational and rotational transitions in virtually all atomic or molecular species. This radiation is thus a prime tool for strongly selective spectroscopic fingerprinting real-time environmental monitoring if broad spectral coverage, short acquisition times high resolution can be achieved – requirements that are mutual competition traditional applications. As novel concept with intrinsic potency three aspects,...
A true enhancement mode heterojunction FET has been developed for low voltage, high efficiency power amplifier applications. 12 mm wide/spl times/1.0 /spl mu/m gate length device-with no additional circuitry-and only a single voltage supply of 3.5 V exhibited output +31.5 dBm with 75% power-added at gain 11.6 dB 850 MHz.