A5082586908- Advanced Fiber Laser Technologies
- Advanced Measurement and Metrology Techniques
- Particle Accelerators and Free-Electron Lasers
- Spectroscopy and Laser Applications
- Advanced Optical Sensing Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Gyrotron and Vacuum Electronics Research
- Advanced Surface Polishing Techniques
- Semiconductor Lasers and Optical Devices
- Optical Wireless Communication Technologies
- Photonic and Optical Devices
- Scientific Measurement and Uncertainty Evaluation
- Particle accelerators and beam dynamics
- Advanced Sensor Technologies Research
- Geophysics and Sensor Technology
- Optical Coherence Tomography Applications
- Ocular and Laser Science Research
- Tryptophan and brain disorders
- Molecular Communication and Nanonetworks
- Particle Detector Development and Performance
- Space Science and Extraterrestrial Life
- Schizophrenia research and treatment
- Advanced Chemical Sensor Technologies
- Space exploration and regulation
- Mass Spectrometry Techniques and Applications
University of Chicago
2023-2024
Fraunhofer UK Research
2018-2024
Applied Photonics (United Kingdom)
2017-2022
Fraunhofer Centre for Applied Photonics
2015-2022
National Physical Laboratory
2014-2015
University of Oxford
2014
Mater Health Services
2010
Mater Misericordiae Hospital
2010
University of California, Santa Barbara
1991
We present an implementation of absolute distance measurement system which uses frequency scanning interferometry (FSI). The technique, referred to as dynamic FSI, two lasers, a gas absorption cell and reference interferometer determine the unknown optical path length difference (OPD) one or many interferometers. is for traceable international standards through knowledge frequencies its features. OPD interferometers can vary during variation measured at sampling rate (2.77 MHz in described...
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
Frequency scanning interferometry is a well-known technique to measure the distance reflecting target. However, variations in optical path length during finite measurement time severely limit applicability of method real-world environments. By use second swept source measurements become immune these variations. The implies great increase costs and complexity. In this letter, we explore possibility using four wave mixing for generation secondary frequency source. This greatly reduces solves...
Standoff scanning dual-comb spectroscopy of explosive materials is demonstrated with quantum cascade lasers at <inline-formula> <tex-math notation="LaTeX">$\sim 8~\mu \text{m}$ </tex-math></inline-formula>. The proof-of-concept the spectrometer, capable detection and identification a distance 3 m, has limit cyclotrimethylenetrinitramine (RDX) pentaerythritol tetranitrate (PETN) on various surfaces 5–<inline-formula> notation="LaTeX">$8~\mu \text{g}$...
ATF2 is a final-focus test beam line which aims to focus the low emittance from ATF damping ring vertical size of about 37 nm and demonstrate nanometer level stability. Several advanced diagnostics feedback tools are used. In December 2008, construction installation were completed commissioning started, supported by an international team Asian, European, U.S. scientists. The present status first results described.
We report on mid-IR spectroscopic measurements performed with rapidly tunable external cavity quantum cascade lasers (EC-QCLs). Fast wavelength tuning in the is realized by a microoptoelectromechanical systems (MOEMS) grating oscillating at resonance frequency of about 1 kHz deflection amplitude up to 10 deg. The entire spectral range broadband QCL can therefore be covered just 500 μs, paving way for real-time spectroscopy region. In addition its use conducted backscattering and transmission...
A lower limit-the Cramér-Rao bound-on the variance of frequency scanning interferometry (FSI) distance measurements in presence noise is presented. We show that, with a suitable analysis method, experimental almost reaches this limit. In particular, results simple method was 1.54 times limit over range signal-to-noise ratios. This bound aids understanding FSI measurement uncertainty, and provides benchmark against which to compare algorithms.
Quantum key distribution (QKD) is a theoretically proven future-proof secure encryption method that inherits its security from fundamental physical principles. Craft Prospect, working with number of UK organisations, has been focused on miniaturising the technologies enable QKD so they may be used in smaller platforms including nanosatellites. The significant reduction size, and therefore cost launching quantum communication either dedicated platform or hosted as part larger optical...
Objective: The control of breathing must continuously adapt in response to homeostatic changes. This is particularly important the context chemical exposure substances such as opioids and anesthetic gases known suppress drive for breathing. While these agents through different modalities, how they affect neuromodulatory networks capable influencing remains unknown. ongoing study aims understand ultrapotent synthetic opioid (UPSO), fentanyl, gas, isoflurane, relationship between LC activity...
Free-space optical links are important for "last-mile" connectivity of future classical and quantum networks, in locations where it is impractical or too costly to run fibre. In this presentation, we will discuss the challenges such present, strategies overcoming these. Results a building-to-building test link over approximately 150 m be presented.
Narrow-bandwidth operation of a quasicontinuous free-electron laser by seed injection has been demonstrated. The pulse-to-pulse frequency bandwidth reduced from 1.6 to 0.16 GHz. An order-of-magnitude reduction the sideband-mode beating in single pulse and 30% start-up time obtained. Numerical simulations multimode show that suppression buildup coherence are rather slow, underlining importance seeding obtain single-mode for available length.
Here we report our recent achievements towards a compact, portable, handheld device for contactless real-time detection and identification of explosives hazardous substances via reflectance spectroscopy in the 7.5 μm – 10 spectral region. The mid-IR spectroscopic measurement principle relies on selective illumination target using broadly tunable external cavity quantum cascade lasers (EC-QCLs). A resonant micro-opto-electro-mechanical systems (MOEMS) grating enables fast wavelength tuning...
We present results from our recent development of a multi-beam Doppler lidar system for accurate 3-dimensional wind measurements. The eye-safe all-fibre consists single seed laser that is amplified in multiple stages and shared between the three emitters. Steps towards turbine blade integration will be outlined.
GPS location services have benefited the lives of millions. But what if it was possible to perform similar measurements using optical instead microwave wavelengths? We investigate potential and challenges an analogue GPS.
Pairing an environmental context with repeat opioid use (ROU) can result in increased tolerance to the effects of opioid. This context-dependent has been extensively studied respect analgesic opioids, yet a knowledge gap exists understanding whether there is that develops induced respiratory depression (OIRD). While activity Locus Coeruleus (LC), primary noradrenergic center brain, involved cue-reward related behaviors, it also enhances breathing response changes blood gas homeostasis. The...
Measuring the linewidth of single-frequency lasers is challenging, and great care must be taken to understand capabilities limitations different measurement techniques obtain consistent results. A detailed comparative study will presented.
The stand-off, range-resolved detection of hydrogen production rates is a valuable mechanism for the long-term condition monitoring packages containing intermediate-level nuclear materials. To exploit this effect we have developed long-range optical sensor system which uses Raman hydrogen. Our need operation over extended ranges (up to 100m) results in very low signals. We therefore use time-correlated (with respect outgoing excitation laser pulse) and spectrally-resolved single-photon...
A proof-of-concept of a scanning stand-off dual-comb spectrometer for explosives detection and identification at 3 m distance is demonstrated. Detection two types explosives: RDX PETN on various surfaces was carried out in reflection-absorption backscattering modes. area 18 cm X (400 pixels) covered ~2.5 sec. Identification method based Pearson's correlation coefficients between the recorded (backscatter reflection) spectra transmission (reflection) FTIR substances, with baseline subtraction...