A5024304494- Advanced Fiber Laser Technologies
- Stellar, planetary, and galactic studies
- Photonic and Optical Devices
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Advanced Photonic Communication Systems
- Astrophysics and Star Formation Studies
- Optical Network Technologies
- Laser-Matter Interactions and Applications
- Mechanical and Optical Resonators
- Gamma-ray bursts and supernovae
- Advanced Frequency and Time Standards
- Astronomical Observations and Instrumentation
- Photonic Crystal and Fiber Optics
- Adaptive optics and wavefront sensing
- Atomic and Subatomic Physics Research
- Advanced Fiber Optic Sensors
- Solid State Laser Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Random lasers and scattering media
- Galaxies: Formation, Evolution, Phenomena
- Optical Polarization and Ellipsometry
- Optical Wireless Communication Technologies
- Space Exploration and Technology
- Astrophysical Phenomena and Observations
United States Air Force Research Laboratory
2019-2023
University of Colorado Boulder
2017-2023
National Institute of Standards and Technology
2017-2023
Kirtland Air Force Base
2019-2022
National Institute of Standards
2018-2021
University of Colorado System
2018-2021
Purdue University West Lafayette
2011-2016
University of Canberra
2016
Washington University in St. Louis
2013
Kerr frequency combs generated from microresonators are the subject of intense study. Most research employs with anomalous dispersion, for which modulation instability is believed to play a key role in initiation comb. Comb generation normal dispersion has also been reported but less well understood. Here we report detailed investigation few-moded, silicon nitride microresonators, showing that mode coupling can strongly modify local even changing its sign. We demonstrate link between and...
Optical resonators with high quality factors (Qs) are promising for a variety of applications due to the enhanced nonlinearity and increased photonic density states at resonances. In particular, frequency combs (FCs) can be generated through four-wave mixing in high-Q microresonators made from Kerr nonlinear materials such as silica, silicon nitride, magnesium fluoride, calcium fluoride. These devices have potential on-chip metrology high-resolution spectroscopy, high-bandwidth...
Broadband travelling-wave electro-optic modulators made of lithium niobate have reached a high level technological maturity.They can provide simultaneously low Vπ, sustain power (both optical and RF) yet propagation loss.By combining together these features, we present high-power handling, broadly tunable, frequency comb generator.The device produces between 60-75 lines within -10 dB bandwidth over its full tuning range -from 6-18 GHz-and handle up to 1W input power.This platform is very...
Controlling femtosecond optical pulses with temporal precision better than one cycle of the carrier field has a profound impact on measuring and manipulating interactions between light matter. We explore that are carved from continuous-wave laser via electro-optic modulation realize regime sub-cycle control without mode-locked resonator. Our ultrafast source, repetition rate 10 GHz, is derived an optical-cavity-stabilized microwave-cavity-stabilized electronic oscillator. Sub-cycle timing...
We present a 32 channel indium phosphide integrated pulse shaper with 25 GHz spacing, where each is equipped semiconductor optical amplifier allowing for programmable line-by-line gain control submicrosecond reconfigurability. critically test the by using it in comb-based RF-photonic filtering experiments precise leveraged to synthesize high-fidelity RF filters which we reconfigure on microsecond time scale. Our on-chip shaping demonstration unmatched its combination of speed, fidelity, and...
Abstract The warm Neptune GJ 3470b transits a nearby ( d = 29 pc) bright slowly rotating M1.5-dwarf star. Using spectroscopic observations during two with the newly commissioned NEID spectrometer on WIYN 3.5 m Telescope at Kitt Peak Observatory, we model classical Rossiter–McLaughlin effect, yielding sky-projected obliquity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>λ</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>98</mml:mn>...
Abstract We present the discovery of TOI-5205b, a transiting Jovian planet orbiting solar metallicity M4V star, which was discovered using Transiting Exoplanet Survey Satellite photometry and then confirmed combination precise radial velocities, ground-based photometry, spectra, speckle imaging. TOI-5205b has one highest mass ratios for M-dwarf planets, with ratio almost 0.3%, as it orbits host star that is just 0.392 ± 0.015 M ⊙ . Its planetary radius 1.03 0.03 R J , while 1.08 0.06...
We validate the discovery of a 2 Earth radii sub-Neptune-size planet around nearby high proper motion M2.5-dwarf G 9-40 (EPIC 212048748), using high-precision near-infrared (NIR) radial velocity (RV) observations with Habitable-zone Planet Finder (HPF), precision diffuser-assisted ground-based photometry custom narrow-band photometric filter, and adaptive optics imaging. At distance $d=27.9\mathrm{pc}$, 9-40b is second closest transiting discovered by K2 to date. The planet's large transit...
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs. TOI-3714 ($V=15.24,~J=11.74$) is an M2 dwarf hosting a hot Jupiter ($M_p=0.70 \pm 0.03~\mathrm{M_J}$ and $R_p=1.01 0.03~\mathrm{R_J}$) on orbital period $2.154849 0.000001$ days with resolved white companion. TOI-3629 ($V=14.63,~J=11.42$) M1 ($M_p=0.26 0.02~\mathrm{M_J}$ $R_p=0.74 0.02~\mathrm{R_J}$) $3.936551_{-0.000006}^{+0.000005}$ days. characterize each transiting companion using combination...
Abstract Fundamental science, as well all communications and navigation systems, are heavily reliant on the phase, timing, synchronization provided by low‐noise agile frequency sources. Although research into varied photonic electronic schemes have strived to improve upon spectral purity of microwave millimeter‐wave signals, reliance conventional synthesis for tuning has resulted in limited progress broadband Using a digital‐photonic synthesizer architecture that derives its time‐base from...
The discovery and characterization of exoplanets around nearby stars is driven by profound scientific questions about the uniqueness Earth our Solar System, conditions under which life could exist elsewhere in Galaxy. Doppler spectroscopy, or radial velocity (RV) technique, has been used extensively to identify hundreds exoplanets, but with notable challenges detecting terrestrial mass planets orbiting within habitable zones. We describe infrared RV spectroscopy at 10 m Hobby-Eberly...
Abstract Barnard’s star is among the most studied stars given its proximity to Sun. It often considered radial velocity (RV) standard for fully convective due RV stability and equatorial decl. Recently, an <?CDATA $M\sin i=3.3{M}_{\oplus }$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi> <mml:mi>sin</mml:mi> <mml:mi>i</mml:mi> <mml:mo>=</mml:mo> <mml:mn>3.3</mml:mn> <mml:msub> <mml:mrow> </mml:mrow> <mml:mo>⊕</mml:mo> </mml:msub> </mml:math>...
We present the discovery of a new Jovian-sized planet, TOI-3757 b, lowest density planet orbiting an M dwarf (M0V). It orbits solar-metallicity discovered using TESS photometry and confirmed with precise radial velocities (RV) from HPF NEID. With planetary radius $12.0^{+0.4}_{-0.5}$ $R_{\oplus}$ mass $85.3^{+8.8}_{-8.7}$ $M_{\oplus}$, not only does this object add to small sample gas giants ($\sim 10$) around dwarfs, but also, its low ($\rho =$ $0.27^{+0.05}_{-0.04}$ $\textrm{g~cm}^{-3}$)...
Beginning with a continuous wave laser at 1064 nm, we generate 30 GHz electro-optic frequency comb which contains 100 lines spanning 3 THz. The initial is subsequently amplified, spectrally broadened in normal dispersion photonic crystal fiber, and then temporally compressed to provide 74 fs pulses average power of up 2.6 W. When launched into second fiber anomalous dispersion, supercontinuum 800-1350 nm generated. Second harmonic generation allows for extension the visible, yielding greater...
Abstract Young, rapidly rotating M dwarfs exhibit prominent starspots, which create quasiperiodic signals in their photometric and Doppler spectroscopic measurements. The periodic can mimic radial velocity (RV) changes expected from orbiting exoplanets. Exoplanets be distinguished activity-induced false positives by the chromaticity long-term incoherence of starspot signals, but these qualities are poorly constrained for fully convective stars. Coherent on may persist hundreds rotations,...
Optical clocks are emerging as next-generation timekeeping devices with technological and scientific use cases. Simplified atomic sources such vapor cells may offer a straightforward path to field use, but suffer from long-term frequency drifts environmental sensitivities. Here, we measure laboratory optical clock based on warm rubidium atoms find low levels of drift the month-long timescale. We observe quantify helium contamination inside glass cell by gradually removing via vacuum...
We present a programmable multitap microwave photonic filter with an arbitrary phase response operating over broad bandwidth. Complex coefficient taps are achieved by optical line-by-line pulse shaping on 10 GHz flat frequency comb using novel interferometric scheme. Through high-speed real-time measurements, we demonstrate chirp control of waveform via filtering. This achievement enables us to compress broadband signals their corresponding bandwidth-limited duration.
Recent research on time cloaking has revealed a fascinating approach to hide temporal events from an interrogating optical field, by opening up and subsequently closing intensity gaps in probe beam. Experiments thus far have demonstrated of nonlinear interactions high-speed data. Here we report cloak with the new capability not only data, but also concurrently transmit it along another wavelength channel for subsequent readout, masking information one observer while directing another....
Understanding the dynamics and kinematics of out-flowing atmospheres hot warm exoplanets is crucial to understanding origins evolutionary history near evaporation desert. Recently, ground based measurements meta-stable Helium atom's resonant absorption at 10830 \AA~has become a powerful probe base environment which driving outflow exoplanet atmospheres. We report evidence for He I \AA~in (equivalent width $\sim$ $0.012 \pm 0.002$ \AA) in exosphere Neptune orbiting M-dwarf GJ 3470, during...
Early in their lives, planets endure extreme amounts of ionizing radiation from host stars. For with primordial hydrogen and helium-rich envelopes, this can lead to substantial mass loss. Direct observations atmospheric escape young planetary systems help elucidate critical stage evolution. In work, we search for metastable helium absorption---a tracer tenuous gas escaping atmospheres---during transits three orbiting the solar analogue V1298 Tau. We characterize stellar line using HET/HPF,...
Abstract We obtained high-resolution spectra of the ultracool M-dwarf TRAPPIST-1 during transit its planet “b” using two high-dispersion near-infrared spectrographs, Infrared Doppler (IRD) instrument on Subaru 8.2m telescope, and Habitable Zone Planet Finder (HPF) 10 m Hobby–Eberly Telescope. These spectroscopic observations are complemented by a photometric observation for APO/ARCTIC, which assisted us in capturing correct times our spectroscopy. Using data new IRD HPF observations, as well...
Theories of planet formation predict that low-mass stars should rarely host exoplanets with masses exceeding Neptune. We used radial velocity observations to detect a Neptune-mass exoplanet orbiting LHS 3154, star is nine times less massive than the Sun. The exoplanet's orbital period 3.7 days, and its minimum mass 13.2 Earth masses. simulations show high planet-to-star ratio (>3.5 × 10-4) not an expected outcome either core accretion or gravitational instability theories formation. In...
We demonstrate a multichannel time-multiplexed radio-frequency arbitrary waveform generator. The system combines switching scheme of multiwavelength optical frequency combs with novel 2-D line-by-line pulse shaper featuring broad bandwidth operation over large temporal windows. Switching times within clock period 200 ps among the four channels is successfully achieved. With finer resolution, number can be scaled up without increasing components.
Abstract We confirm the planetary nature of TOI-1728b using a combination ground-based photometry, near-infrared Doppler velocimetry and spectroscopy with Habitable-zone Planet Finder. TOI-1728 is an old, inactive M0 star T eff = <?CDATA ${3980}_{-32}^{+31}$?> K, which hosts transiting super-Neptune at orbital period ∼3.49 days. Joint fitting radial velocities TESS transits yields radius ${5.05}_{-0.17}^{+0.16}$?> R ⊕ , mass ${26.78}_{-5.13}^{+5.43}$?> M eccentricity...
We confirm the planetary nature of TOI-532b, using a combination precise near-infrared radial velocities with Habitable-zone Planet Finder, TESS light curves, ground based photometric follow-up, and high-contrast imaging. TOI-532 is faint (J$\sim 11.5$) metal-rich M dwarf Teff = $3957\pm69$ K [Fe/H] $0.38\pm0.04$; it hosts transiting gaseous planet period $\sim 2.3$ days. Joint fitting ground-based transits reveal radius $5.82\pm0.19$ R$_{\oplus}$, mass $61.5_{-9.3}^{+9.7}$ M$_{\oplus}$....