A5073105193- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Solid State Laser Technologies
- Advanced Frequency and Time Standards
- Photorefractive and Nonlinear Optics
- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Particle accelerators and beam dynamics
- Adaptive optics and wavefront sensing
- Geochemistry and Geologic Mapping
- Spectroscopy and Laser Applications
- Astro and Planetary Science
- Image Processing and 3D Reconstruction
- Silicon Nanostructures and Photoluminescence
- Glaucoma and retinal disorders
- Chalcogenide Semiconductor Thin Films
- Atomic and Molecular Physics
- Astrophysics and Star Formation Studies
- Silicon and Solar Cell Technologies
- Image and Object Detection Techniques
Heriot-Watt University
2019-2024
Scottish Universities Physics Alliance
2019-2023
University of Lisbon
2022
Brera Astronomical Observatory
2022
Institute of Astrophysics and Space Sciences
2022
The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes Dispersion Echelle Spectrograph). consists three fibre-fed spectrographs (UBV, RIZ, YJH) providing a spectral ∼100,000 with minimum simultaneous wavelength coverage 0.4-1.8 µm the goal extending it to 0.35-2.4 addition K band spectrograph. It operates both in seeing- diffraction-limited conditions fibre-feeding allows several,...
Cosmological and exoplanetary science using transformative telescopes like the ELT will demand precise calibration of astrophysical spectrographs in blue-green, where stellar absorption lines are most abundant. Astrocombs-lasers providing a broadband sequence regularly-spaced optical frequencies on multi-GHz grid-promise an atomically-traceable scale, but their realization blue-green is challenging for current infrared-laser-based technology. Here, we introduce concept achieving broad,...
The Extremely Large Telescope (ELT) will address an unprecedented optical wavelength range from 370 to 2400 nm, and its high-resolution spectrograph (HIRES) require a laser frequency comb calibrator of comparable coverage. An architecture based around Ti:sapphire master in principle enables wavelengths across this be obtained by combination second- third-order nonlinear effects. In scheme, near-infrared coverage can addressed downconversion the 1600 nm using parametric oscillator (OPO),...
Broadband UV-green generation is achieved from a 1-GHz Ti:sapphire frequency comb using Zn-indiffused, grating-engineered MgO:PPLN ridge waveguide. Etalon-filtering produces 30 GHz astrocomb 390–480 nm, with modes resolvable by an Echelle-prism spectrograph.
Stable operation of a doubly resonant femtosecond optical parametric oscillator (OPO) requires submicron matching the OPO and pump laser cavity lengths, which is normally implemented using dither-locking feedback scheme. Here we show that parasitic sum-frequency mixing between pulses degenerate provides an error signal suitable for actuating length with precision needed to maintain oscillation on single fringe at maximum output power. Unlike commonly used approaches, method introduces no...
High-resolution cross-dispersion spectrographs are widely used in spectroscopy, but the two-dimensional format of spectrum requires sophisticated calibration, conventionally performed by illuminating instrument with a broadband hollow-cathode lamp and cross-referencing result to an emission-line atlas. Here, we introduce new technique completely calibrate high-resolution echelle spectrograph using only laser frequency comb. Selected individual comb lines removed from 20 GHz comb-revealing...
The instrumentation plan for the ELT foresees ArmazoNes high Dispersion Echelle Spectrograph (ANDES). ANDES-project and consortium entered phase B in January 2022 underwent several (internal external) revisions by now to ensure that requirements eventually challenging goals can be met physical design of spectrograph. <br/> <br clear="all"/> Among its main scientific are detection atmospheres exoplanets determination fundamental constants. For this, radial velocity precision accuracy...
We introduce a simple and compact diode-pumped Pr:YLF-Cr:LiCAF laser, operating at 813.42 nm providing 130-mW, single-frequency output tunable over 3-GHz range. The laser has short-term intrinsic linewidth estimated to be 700 Hz (β-separation method), while exhibiting free-running wavelength stability of below 1 pm in one hour. Using feed-forward technique we demonstrate the integration into fully stabilized, 1-GHz Ti:sapphire frequency comb, resulting heterodyne beat note between comb with...
The characterization of Earth-like exoplanets and precision tests cosmological models using next-generation telescopes such as the ELT will demand precise calibration astrophysical spectrographs in visible region, where stellar absorption lines are most abundant. Astrocombs--lasers providing a broadband sequence ultra-narrow, drift-free, regularly spaced optical frequencies on multi-GHz grid--promise an atomically-traceable, versatile scale, but their realization is challenging because need...
We report a synchronously pumped degenerate optical parametric oscillator (DRO) with 90-nm bandwidth at 1.634 μm, producing 400-mW average power femtosecond pulses 10 GHz, the highest repetition frequency DRO demonstrated to date.
The first generation of ELT instruments includes an optical-infrared high-resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). consists three fibre-fed spectrographs ([U]BV, RIZ, YJH) providing a spectral resolution $\sim$100,000 with minimum simultaneous wavelength coverage 0.4-1.8 $\mu$m the goal extending it to 0.35-2.4 addition U arm BV spectrograph separate K band spectrograph. It operates both in seeing-...
High-resolution echelle spectrographs are critical for modern astronomy. Determining their wavelength solution is a prerequisite calibration, conventionally performed by illuminating the instrument with broadband hollow-cathode lamp and cross-referencing resulting two-dimensional spectrum to an emission-line atlas. Challenging requirements nextgeneration spectrograph calibration driving adoption of laser frequency combs in place lamps. Laser offer exceptional relative scale, but task...
Next generation extreme precision radial velocity (EPRV) instruments such as the ANDES spectrograph of Extremely Large Telescope will require an unprecedentedly high-precision calibration approach, particularly in UB band region which most dense stellar absorption lines are present. For this purpose, astrocombs delivering thousands atomically referenced, evenly-spaced across a broad spectrum have potential to be ideal sources. Here, we report novel and effective approach generating laser...
Optical parametric oscillators (OPOs), pumped by Ti:sapphire and Yb-doped femtosecond lasers, provide unique capabilities to address a broad range of parameters interest precision spectroscopy. We review here variety OPOs under development that offer tuning from 1.5 13 μm, repetition rates 100 MHz 10 GHz pulse durations < 25 fs few picoseconds. Spectroscopic techniques revealing the individual frequency comb modes are discussed, along with dual-comb spectroscopy at 3 μm 6-8 μm.
The Extremely Large Telescope (ELT), currently under construction in Chile, aims to investigate exoplanet atmospheric spectroscopy, star / planet formation and evolution, cosmology fundamental physics with a broadband high-resolution spectrograph, designated ELT-HIRES. Comprising four modules covering wavelengths from 370-2500 nm, this instrument requires laser comb calibration mode spacings 32 GHz (<; 600 nm) 6 (>1950 nm). As illustrated by our recent review paper [1], approaches date based...
The potential for diode-pumped solid-state (DPSS) lasers to provide narrow-linewidth and high-power outputs with excellent beam quality has motivated their development as sub-components optical lattice clocks. A suitable laser candidate such application should be compact in size while able a repeatable frequency output stability. Here, we report single frequency, Pr:YLF-Cr:LiCAF operating at the magic wavelength of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
A new stabilization paradigm for degenerate femtosecond OPOs is demonstrated in a Ti:sapphire-pumped PPKTP OPO. Based on parasitic sum-frequency mixing, the approach achieves long-term locking and tenfold reduction relative-intensity noise compared with dither-locking.
We present a 10-GHz astrocomb spanning 1.15–1.8 µm and based on spectrally broadened degenerate optical parametric oscillator. Absolute mode identification is provided by Fourier-transform spectrometer cross-calibrated to the comb-mode spacing.
The specification of the HIRES spectrograph proposed for forthcoming Extremely Large Telescope (ELT) requires a traceable calibration source with gap-free coverage from 370–2500 nm, except region 1350– 1440 nm aligned atmospheric absorption [1] . In [2] we described route to broadband astrocomb 0.5 2.2 µm based on 1-GHz Ti:sapphire oscillator and phase-coherent optical parametric (OPO). We now report development this work which has demonstrated 10-GHz extended degenerate (OPO), producing...