A5065108385- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Optical Systems and Laser Technology
- Advanced optical system design
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Optical Wireless Communication Technologies
- Particle Accelerators and Free-Electron Lasers
- Spectroscopy and Laser Applications
- Optical measurement and interference techniques
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Optical Coherence Tomography Applications
- Solar Radiation and Photovoltaics
- Semiconductor Lasers and Optical Devices
- Astrophysics and Star Formation Studies
- Optical Coatings and Gratings
- Photonic and Optical Devices
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Astrophysics and Cosmic Phenomena
- Ophthalmology and Visual Impairment Studies
- Ionosphere and magnetosphere dynamics
University of California, Santa Cruz
2012-2024
Lickenbrock
2023
Indian Institute of Astrophysics
2023
University of California, Irvine
2023
University of California, Riverside
2010
Lawrence Livermore National Laboratory
2010
University of Hawaii System
1994-2002
Monterey Institute for Research in Astronomy
2000
National Solar Observatory
1994
University of Hawaiʻi at Mānoa
1994
A new high-order adaptive optics system is now being commissioned at the Lick Observatory Shane 3-meter telescope in California. This uses a high return efficiency sodium beacon and combination of low deformable mirrors to achieve diffraction-limited imaging over wide spectrum infrared science wavelengths covering 0.8 2.2 microns. We present design performance goals first on-sky test results. discuss several innovations that make this pathfinder for next generation AO systems. These include...
The Lick Observatory 3-meter telescope has a history of serving as testbed for innovative adaptive optics techniques. In 1996, it became one the first astronomical observatories to employ laser guide star (LGS) facility instrument available astronomy community. Work on second-generation LGS system, ShaneAO, is well underway, with plans deploy in 2013. this paper we discuss key design features and implementation ShaneAO system. Once again, Shane 3-m will host number new techniques...
We describe the design and first-light early science performance of Shane Adaptive optics infraRed Camera-Spectrograph (ShARCS) on Lick Observatory's 3-m telescope. Designed to work with new ShaneAO adaptive system, ShARCS is capable high-efficiency, diffraction-limited imaging low-dispersion grism spectroscopy in J, H, K-bands. uses a HAWAII-2RG infrared detector, giving high quantum efficiency (>80%) Nyquist sampling diffraction limit all three wavelength bands. The instrument also...
The Lick Observatory's Shane 3-meter telescope has been upgraded with a new infrared instrument (ShARCS - Adaptive optics infraRed Camera and Spectrograph) dual-deformable mirror adaptive (AO) system (ShaneAO). We present first-light measurements of imaging sensitivity in the Ks band. compare mea- sured results to predicted signal-to-noise ratio magnitude limits from modeling emissivity throughput ShaneAO ShARCS. model was validated by comparing its Keck then estimating sky background...
Liger is an adaptive optics (AO) fed imager and integral field spectrograph (IFS) designed to take advantage of the Keck All-sky Precision Adaptive-optics (KAPA) upgrade I telescope. adapts design InfraRed Imaging Spectrograph (IRIS) for Thirty Meter Telescope (TMT) by implementing a new re-imaging optics. The performance critical as it sequentially feeds contains essential components such pupil wheel, filter viewing camera. We present structural analysis optical assembly including static,...
We report on the preliminary design of W.M. Keck Observatory's (WMKO's) next-generation adaptive optics (NGAO) facility. This facility is designed to address key science questions including understanding formation and evolution today's galaxies, measuring dark matter in our galaxy beyond, testing theory general relativity Galactic Center, planetary systems around nearby stars, exploring origins own solar system. The requirements derived from these have resulted NGAO being near...
By inserting a MEMS deformable mirror-based adaptive optics system into the beam transfer of Shane 3-meter telescope at Mt. Hamilton, we actively controlled wavefront outgoing sodium laser guidestar beam. It was possible to show that purposefully aberrated resulted in poorer performance Adaptive Optics located behind primary, though bad seeing conditions prevented us from improving system's over its nominal state. A silver-coated Iris AO mirror subjected approximately 9.5 hours exposure 3.5...
High-multiplex and deep spectroscopic follow-up of upcoming panoramic deep-imaging surveys like LSST, Euclid, WFIRST is a widely recognized increasingly urgent necessity. No current or planned facility at U.S. observatory meets the sensitivity, multiplex, rapid-response time needed to exploit these future datasets. FOBOS, Fiber-Optic Broadband Optical Spectrograph, near-term fiber-based that addresses needs by optimizing depth over area exploiting aperture advantage existing 10m Keck II...
The Santa Cruz Extreme AO Lab (SEAL) is a new visible-wavelength testbed designed to advance the state of art in wavefront control for high contrast imaging on large, segmented, ground-based telescopes. SEAL provides multiple options simulating atmospheric turbulence, including custom spatial light modulator. A 37-segment deformable mirror simulates W. M. Keck Observatory segmented primary mirror. adaptive optics system consists woofer/tweeter DM system, and four sensor arms: 1) high-speed...
Context. Adaptive optics (AO) is a technique for improving the resolution of ground-based telescopes by correcting optical aberrations due to atmospheric turbulence and telescope itself in real time. With rise giant segmented-mirror (GSMT), AO needed more than ever reach full potential these future observatories. One main performance drivers an system wavefront-sensing operation, consisting measuring shape described above. Aims. The nonmodulated pyramid wavefront sensor (nPWFS) with high...
We present the design of SCALES (Slicer Combined with Array Lenslets for Exoplanet Spectroscopy) a new 2-5 micron coronagraphic integral field spectrograph under construction Keck Observatory. enables low-resolution (R∼50) spectroscopy, as well medium-resolution (R∼4,000) spectroscopy goal discovering and characterizing cold exoplanets that are brightest in thermal infrared. Additionally, has 12x12" field-of-view imager will be used general adaptive optics science at Keck. SCALES's...
The Next Generation Adaptive Optics (NGAO) system will represent a considerable advancement for high resolution astronomical imaging and spectroscopy at the W. M. Keck Observatory. AO incorporate multiple laser guidestar tomography to increase corrected field of view remove cone effect inherent single guide star systems. improvement permit higher Strehl correction in near-infrared diffraction-limited down R band. A actuator count micro-electromechanical (MEMS) deformable mirror provide...
One important frontier for astronomical adaptive optics (AO) involves methods such as Multi-Object AO and Multi-Conjugate that have the potential to give a significantly larger field of view than conventional techniques. A second key emphasis over next decade will be push visible wavelengths. We conducted first laboratory simulations wide-field, laser guide star at wavelengths on 10-meter-class telescope. These experiments, utilizing UCO/Lick Observatory's / Laser Tomography Adaptive Optics...
IRIS is a diffraction limited instrument designed for first light of the Thirty Meter Telescope (TMT). It combines nearinfrared integral field spectrograph (lenslet array and mirror slicer) wide-field imager with platescales as small 4 mas. The project nearing end its final design phase will soon be ready fabrication. Our team has created wide variety prototypes solutions this advanced instrument. While many challenges like atmospheric dispersion correction saturation are particularly acute...
We present first results from the Multi-Conjugate and Multi-Object Adaptive Optics (MCAO MOAO) testbed, at UCO/Lick Laboratory for (LAO) facility U.C. Santa Cruz. This testbed is constructed to simulate a 30-m telescope executing MCAO and/or open loop MOAO atmospheric compensation imaging over 5 arcminutes. It capable of performing Shack-Hartmann wavefront sensing on up 8 natural or laser guide stars 2-3 additional tip/tilt stars. In this paper, we demonstrate improved on-axis correction...
We report on the development of wavefront reconstruction and control algorithms for multiconjugate adaptive optics (MCAO) results testing them in laboratory under conditions that simulate an 8 meter class telescope. The University California Observatories (UCO) Lick Observatory Laboratory Adaptive Optics testbed allows us to test wide-field-of-view systems as they might be instantiated near future giant telescopes. In particular, we have been investigating performance MCAO using five laser...
SCALES (Santa Cruz Array of Lenslets for Exoplanet Spectroscopy) is a 2-5 micron high-contrast lenslet integral-field spectrograph (IFS) driven by exoplanet characterization science requirements and will operate at W. M. Keck Observatory. Its fully cryogenic optical train uses custom silicon array, selectable coronagraphs, dispersive prisms to carry out integral field spectroscopy over 2.2 arcsec view with low (< 300) spectral resolution. A small, dedicated section the array feeds an image...
A next-generation instrument named, Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy (SCALES), is being planned the W. M. Keck Observatory. SCALES will have an integral field spectrograph (IFS) and a diffraction-limited imaging channel to discover spectrally characterize directly imaged exoplanets. Operating at thermal infrared wavelengths (1-5 μm, goal 0.6-5 μm), designed cover 12′′ × view low distortions high throughput. Apart from expanding mid-infrared science cases...
Pyramid wavefront sensors offer an alternative to traditional Hartmann sensing for measurement in astronomical adaptive optics systems. The sensor has been described as a slope with potential sensitivity gains over the Shack sensor, but actuality seems exhibit traits of both and direct phase sensor. original configuration, utilizing glass pyramids modulation techniques, is difficult implement. We present results laboratory experiments using that utilizes micro-optic lenslet array place...
We have demonstrated MOAO-type atmospheric compensation on a 10 meter telescope at visible wavelengths with the UCO/Lick MCAO/MOAO testbed in Laboratory for Adaptive Optics UCSC. report Strehls of ~20% R band (658 nm) on-axis and ~15% off-axis 25" 3D Mauna Kea-type atmosphere r0 = 15 cm &Tgr;<sub>0</sub> 3.5". show that tomographic MOAO approach 5 LGS's 50" constellation is sufficient to realize good correction visible. Two major improvements realized this gain: (1) An upgrade 64x64...
SCALES is a high-contrast, infrared coronagraphic imager and integral field spectrograph (IFS) to be deployed behind the W.M. Keck Observatory adaptive optics system. A reflective optical design allows diffraction-limited imaging over large wavelength range (1.0 - 5.0 µm). microlens array-based IFS coupled with lenslet reformatter ("slenslit") allow spectroscopy at both low (R = 35 250) moderate 2000 6500) spectral resolutions. The range, performance, high contrast coronagraphy cryogenic...