A5061975927- Advanced Fiber Laser Technologies
- Advanced Frequency and Time Standards
- Advanced Measurement and Metrology Techniques
- Scientific Measurement and Uncertainty Evaluation
- Advanced Fiber Optic Sensors
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Optical measurement and interference techniques
- Surface Roughness and Optical Measurements
- Spectroscopy and Laser Applications
- Quantum optics and atomic interactions
- Laser Design and Applications
- Retinal and Macular Surgery
- Force Microscopy Techniques and Applications
- Photonic Crystal and Fiber Optics
- Advanced Sensor Technologies Research
- Sensor Technology and Measurement Systems
- Advanced Photonic Communication Systems
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Bat Biology and Ecology Studies
- Advanced Surface Polishing Techniques
- Mechanical and Optical Resonators
- Wildlife Ecology and Conservation
Czech Academy of Sciences, Institute of Scientific Instruments
2015-2024
CESNET, zájmové sdružení právnických osob
2021
Czech Academy of Sciences
2007-2012
Brno University of Technology
2006-2010
Challenging experiments for tests in fundamental physics require highly coherent optical frequency references with suppressed phase noise from hundreds of kHz down to μHz Fourier frequencies. It can be achieved by remote synchronization many interconnected stabilized fibre links. Here we describe the path realize a delocalized reference spectroscopy isomeric state nucleus Thorium-229 atom. This is prerequisite realization next generation an clock - nuclear clock. We present established 235...
The influence of the refractive index air has proven to be a major problem on road improvement uncertainty in interferometric displacement measurements. We propose an approach with two counter-measuring interferometers acting as combination tracking refractometer and interferometer referencing wavelength laser source mechanical standard made material ultra-low thermal expansion. This technique combines length measurement within specified range fluctuations one axis. Errors caused by...
The infrastructure essentialities for accurate time and stable frequency distribution are presented. Our solution is based on sharing fibers a research educational network carrying live data traffic with transfer in parallel. Accurate transmission uses mainly dark channels amplified by dedicated bidirectional amplifiers the same propagation path both directions of transmission. This paper targets challenges related to transmission, particularly, directional nonreciprocities.
We studied ranging and feeding behavior of Cypriot fruit bats during the summer winter, which are critical periods with limited food supply adverse conditions. Seasonal changes in were characterized by a steep increase size core areas home ranges from to winter. Males females did not differ winter ranges, but they differed distance traveled sites. Summer consisted fruits Ficus carica flowers Agave americana. Winter dates, Melia azedarach , Citrus reticulata C. limon Myrtus communis...
Fiber optic infrastructure is essential in the transmission of data all kinds, both for long haul and shorter distances cities. Optical fibers are also preferred infrastructures inside buildings, especially highly secured organizations government facilities. This paper focuses on a reference measurement analysis optical fiber cables sensitivity to acoustic waves. Measurement was carried out an anechoic chamber ensure stable conditions pressure range from 20 Hz kHz. The frequency response,...
We present an interferometric technique based on a differential interferometry setup for measurement under atmospheric conditions. The key limiting factor in any dimensional are fluctuations of the refractive index air representing dominating source uncertainty when evaluated indirectly from physical parameters atmosphere. Our proposal is concept over-determined where reference length derived mechanical frame made material with very low thermal coefficient. allows one to track variations...
In this contribution we propose a scheme for generation of precise displacements through conversion relative stability components femtosecond laser into the length Fabry-Perot cavity. The spacing mirrors interferometer represents mechanical standard referenced to stable optical frequency mode-locked laser. With help highly selective filter, it is possible get only few discrete spectral components. By tuning and locking cavity selected single component with uncertainty repetition To verify...
We present a system of positioning and interferometric monitoring sample position for measurements calibration in the nanoscale metrology. The is based on three-axis stage which allows replacing scanning by probe an atomic force microscope with full displacement measurement. A 200 µm × horizontal travel extends also range. sub-nanometer resolution all three axes under closed loop control detection via capacitive sensors. Interferometric six degrees freedom ensures metrological traceability...
We present a concept of suppression the influence variations refractive index air in displacement measuring interferometry. The principle is based on referencing wavelength coherent laser source atmospheric conditions instead traditional stabilization optical frequency and indirect evaluation air. key advantage identical beam paths position interferometers interferometer used for stabilization. Design arrangement presented here to verify suitable real interferometric sensing technical...
In this paper, a novel principle of contactless gauge block calibration is presented. The combines low-coherence interferometry and laser interferometry. An experimental setup Dowell interferometer Michelson to ensure length determination with direct traceability the primary standard. By monitoring both sides digital camera 3D surface measurements are possible too. presented protected by Czech national patent No. 302948.
The vast majority of physical objects we are dealing with almost exclusively made atoms. Because their discrete level structure, single atoms have proved to be emitters light, which is incompatible the classical description electromagnetic waves. We demonstrate this incompatibility for atomic fluorescence when scaling up size source ensemble, consists trapped ions, by several orders magnitude. presented measurements nonclassical statistics on light unconditionally emitted from ensembles...
Radiotracking is an important and often the only possible method to explore specific habits behaviour of animals, but it has proven be very demanding time-consuming, especially when frequent positioning a large group required. Our aim was address this issue by making process partially automated, mitigate demands related costs. This paper presents novel automated tracking system that consists network stations deployed within target area. Each station reads signals from telemetry transmitters,...
We present a design of nanometrology measuring setup which is part the national standard instrumentation for operated by Czech Metrology Institute (CMI) in Brno, Republic. The system employs full six-axis interferometric position measurement sample holder consisting six independent interferometers. Here we report on description alignment issues and accurate adjustment orthogonality axes. Consequently, suppression cosine errors reduction sensitivity to Abbe offset achieved through control all...
Optical fiber links for distribution of highly-stable optical frequencies were experimentally tested by many metrology laboratories in the past fifteen years. But recent development new sensors industrial application puts demands on a technology transfer this high-end from laboratory experiments to real industry. The remote calibration interrogators Fiber Bragg Grating strain sensory networks is one important examples. We present 306 km long link established Czech Republic where coherent...
Abstract The work presents measurements of the length stability Zerodur glass ceramic with temperature change. Measurement this thermal characteristic is necessary for determination optimal at which has a coefficient expansion close to zero. principle measurement monitor changes using an optical resonator cavity mirror spacer made from material be studied. placed inside vacuum chamber control. A tunable laser diode locked certain mode frequency mode. beat-note signal mixing between and...
A passive optical resonator is a special sensor used for measurement of lengths on the nanometer and sub-nanometer scale. stabilized frequency comb can provide an ultimate reference measuring wavelength tunable laser locked to resonator. If we lock repetition offset frequencies high-grade radiofrequency (RF) oscillator its relative stability transferred from RF domain. Experiments in field precise length metrology low-expansion materials are usually long-term nature so it required that stay...
We present a method of noise suppression laser diodes by an unbalanced Michelson fiber interferometer. The unstabilized source is represented compact planar waveguide external cavity module, ORIONTM (Redfern Integrated Optics, Inc.), working at 1540.57 nm with 1.5-kHz linewidth. built up the interferometer 2.09 km-long arm based on standard telecommunication single-mode (SMF-28) spool to suppress frequency servo-loop control 20 dB 40 within Fourier range, remaining tuning range frequency.
This paper introduces a novel metric and approach for link quality measurement new algorithm human-intervention-free optical balancing, specifically designed fiber transfer systems that require bidirectional amplification. Bidirectional amplification, essential reciprocal paths to compensate fluctuations non-data applications like accurate time ultrastable coherent frequency transfer, complexities such as feedback loops phase inconsistencies. Our work ensures amplified signals maintain...
Abstract We present an experimental arrangement of interferometric system designed to operate with full compensation for varying refractive index air in the measuring axis. The concept is based on a principle where wavelength laser source derived not from optical frequency stabilized but fixed length being base-plate or frame whole setup. This results into stabilization atmospheric conditions mechanical suitable etalon made material very low thermal expansion. ultra-low expanding glass...
Presented paper is focused on description of a system design for monitoring patient head after special ophthalmological operation called Vitrectomy. For optimal recovery correct position the during time important. The designed consists telemetric unit and communication unit. provides periodical tilt sensing using digital MEMS accelerometer. angle corresponding are stored in built-in memory. also warned by sound alarm when posture incorrect. second part this which with via wireless interface....