A5003687749- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Atomic and Subatomic Physics Research
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Quantum optics and atomic interactions
- Laser Design and Applications
- Solid State Laser Technologies
- Semiconductor Quantum Structures and Devices
- Advanced Fiber Optic Sensors
- Quantum Mechanics and Applications
- Scientific Measurement and Uncertainty Evaluation
- Mechanical and Optical Resonators
- Geophysics and Sensor Technology
- Urban Heat Island Mitigation
- Optical Network Technologies
- Radioactive Decay and Measurement Techniques
- Photorefractive and Nonlinear Optics
- Pulsars and Gravitational Waves Research
- Laser-Matter Interactions and Applications
- Quantum Information and Cryptography
- Geophysics and Gravity Measurements
- Astro and Planetary Science
Ferdinand-Braun-Institut
2016-2025
Kirchhoff (Germany)
2010-2025
Humboldt-Universität zu Berlin
2009-2019
Heinrich Heine University Düsseldorf
2003-2017
Forschungsverbund Berlin
2011
Humboldt State University
2010
Max Planck Institute for Gravitational Physics
2002-2008
Max Planck Society
2003-2008
Stanford University
2002-2003
Max Planck Institute of Quantum Optics
2003
Precision time references in space are of major importance to satellite-based fundamental science, global satellite navigation, earth observation, and formation flying.Here we report on the operation a compact, rugged, automated optical frequency comb setup sounding rocket under microgravity.The experiment compared two clocks, one based D 2 transition Rb, another hyperfine splitting Cs.This represents first clock space, which is an important milestone for future precision metrology.Based...
The theory of general relativity describes macroscopic phenomena driven by the influence gravity while quantum mechanics brilliantly accounts for microscopic effects.Despite their tremendous individual success, a complete unification fundamental interactions is missing and remains one most challenging important quests in modern theoretical physics.The STE-QUEST satellite mission, proposed as medium-size mission within Cosmic Vision program European Space Agency (ESA), aims testing with high...
Using an atom interferometer method, we measure the recoil velocity of a cesium due to coherent scattering photon. This measurement is used obtain value ℏ/MCs and fine structure constant, α. The current fractional uncertainty Δα/α = 7.4 × 10-9.
By measurement of the frequency a vibrational overtone transition in molecular hydrogen ion ${\mathrm{HD}}^{+}$, we demonstrate first optical spectroscopy trapped ions with submegahertz accuracy. We use diode laser, locked to stable comb, perform resonance-enhanced multiphoton dissociation on sympathetically cooled ${\mathrm{HD}}^{+}$ at 50 mK. The achieved 2-ppb relative accuracy is factor 150 higher than previous results for and measured agrees well recent high-accuracy ab initio...
The development of compact optical frequency references plays an important role in future timing systems, on the ground and space, including next-generation global-navigation satellite systems. Realization qualification such systems is held back by technical challenges creating robust, reliable devices for metrology under demanding conditions. Here researchers demonstrate autonomous operation I${}_{2}$ reference measurement its using a dual comb sounding rocket, as milestone way to routine...
Abstract Future generations of global navigation satellite systems (GNSSs) can benefit from optical technologies. Especially clocks could back-up or replace the currently used microwave clocks, having potential to improve GNSS position determination enabled by their lower frequency instabilities. Furthermore, clock technologies—in combination with inter-satellite links—enable new architectures, e.g., synchronization distant references within constellation using time and transfer techniques....
Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt operate experimental setups microgravity platforms. We describe design payload, motivations choices, capabilities Bose-Einstein Condensate Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds heritage...
Recent developments in quantum technology have resulted a new generation of sensors for measuring inertial quantities, such as acceleration and rotation. These can exhibit unprecedented sensitivity accuracy when operated space, where the free-fall interrogation time be extended at will environment noise is minimal. European laboratories played leading role this field by developing concepts tools to operate these relevant environment, parabolic flights, towers, or sounding rockets. With...
We present a compact, ultra-narrow-linewidth semiconductor laser based on 780 nm distributed feedback diode optically self-locked to mode of an external monolithic confocal Fabry-Perot resonator. characterize spectral properties the by measuring its frequency noise power density. The white levels at 5 Hz(2)/Hz above Fourier as small 20 kHz. This level is more than five orders magnitude smaller same solitary without resonant optical feedback, and it three narrow linewidth, grating-based,...
We present a micro-integrated, extended cavity diode laser module for space-based experiments on potassium Bose-Einstein condensates and atom interferometry. The emits at the wavelength of D2-line 766.7 nm provides 27.5 GHz continuous tunability. It features sub-100 kHz short term (100 μs) emission linewidth. To qualify quantum optics in space, vibration tests (8.1 g(RMS) 21.4 g(RMS)) mechanical shock (1500 g) were carried out. No degradation electro-optical performance was observed.
We present a simple method to accurately measure the frequency noise power spectrum of lasers. It relies on creating beat note between two lasers, capturing corresponding signal in time domain, and appropriately postprocessing data derive spectrum. In contrast methods already established, it does not require stabilization laser an optical reference, i.e., second laser, cavity or atomic transition. further omits discriminator hence avoids bandwidth limitation nonlinearity effects common...
We have developed, assembled, and flight-proven a stable, compact, autonomous extended cavity diode laser (ECDL) system designed for atomic physics experiments in space. To that end, two micro-integrated ECDLs at 766.7 nm were frequency stabilized during sounding rocket flight by means of modulation spectroscopy (FMS) 39^K offset locking techniques based on the beat note ECDLs. The stabilization as well additional hard- software to test hot redundancy mechanisms implemented part...
We report on the realization of narrow linewidth high power DFB diode lasers emitting near 1064 nm in stable longitudinal and lateral single mode. The is analyzed dependence output for with cavity lengths 1 2 mm by means a heterodyne beat note technique. minimum intrinsic 22 kHz FWHM (full width at half maximum, 100 μ s time scale) an 150 mW length mm. total mainly determined technical noise corresponds to 234 70 mW. influence current investigated compared different lengths. Re-broadening...
We report on a transportable and easy-to-operate optical clock utilizing the 2S1/2 - 2D3/2 transition of single trapped 171Yb+ ion at 436 nm. Developed within pilot project for quantum technology in Germany lead by industry, is set up two 19″ racks. In this way, transportation can easily be realized, large degree automatization allows operation outside highly specialized laboratories applications beyond basic research. Comparisons to existing high-accuracy systems enable verification clock's...
The aim of this study is to detect ventilation corridors in three epochs (1992, 2002 and 2011) by mapping rough urban areas. roughness parameters calculations are based on a 3D building database obtained from satellite imagery (SPOT) for thee conducted accordingly morphometric methods. Several paths clearly recognisable all decades the proximity analysis (by calculating length (z0) zero-plane displacement height (zd)), we established their extent analysed structural developmental changes. We...
We present micro-integrated diode laser modules operating at wavelengths of 767 and 780 nm for cold quantum gas experiments on potassium rubidium. The master-oscillator-power-amplifier concept provides both narrow linewidth emission high optical output power. With a (10 μs) below 1 MHz an power up to 3 W, these are specifically suited optics feature the robustness required operation drop tower or on-board sounding rocket. This technology development hence paves way toward precision in space.
Deep learning models, with a prerequisite of large databases, are common approaches in applying machine for inverse design photonics. For these less expensive, approximate methods usually used to generate which limit their applications. In this study, we compare the performance data-efficient (ML) models predicting characteristics surface Bragg gratings semiconductor ridge waveguides. We employ 3D finite-difference time-domain method is very accurate but time-consuming database. analyze...