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in creator/contributor: "Olivier, S S"

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Tip-tilt compensation: Resolution limits for ground-based telescopes using laser guide star adaptive optics. Revision 2

The angular resolution of long-exposure images from ground-based telescopes equipped with laser guide star adaptive optics systems is fundamentally limited by the the accuracy with which the tip-tilt aberrations introduced by the atmosphere can be corrected. Assuming that a natural star is used as the tilt reference, the residual error due to tilt anisoplanatism can significantly degrade the long-exposure resolution even if the tilt reference star is separated from the object being imaged by a … more

Date: October 8, 1992

Creator: Olivier, S. S.; Max, C. E.; Gavel, D. T. & Brase, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Laser guide star adaptive optics: Present and future

Feasibility demonstrations using one to two meter telescopes have confirmed the utility of laser beacons as wavefront references for adaptive optics systems. Laser beacon architectures suitable for the new generation of eight and ten meter telescopes are presently under study. This paper reviews the concept of laser guide star adaptive optics and the progress that has been made by groups around the world implementing such systems. A description of the laser guide star program at LLNL and some e… more

Date: March 1, 1993

Creator: Olivier, S. S. & Max, C. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Issues in the design and optimization of adaptive optics and laser guide stars for the Keck Telescopes

We discuss issues in optimizing the design of adaptive optics and laser guide star systems for the Keck Telescope. The initial tip-tilt system will use Keck`s chopping secondary mirror. We describe design constraints, choice of detector, and expected performance of this tip-tilt system as well as its sky coverage. The adaptive optics system is being optimized for wavelengths of I-2.2{mu}m. We are studying adaptive optics concepts which use a wavefront sensor with varying numbers of subapertures… more

Date: March 1, 1994

Creator: Max, C. E.; Gavel, D. T. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Performance of adaptive optics at Lick Observatory

A prototype adaptive optics system has been developed at Lawrence Livermore National Laboratory (LLNL) for use at Lick Observatory. This system is based on an ITEX 69-actuator continuous-surface deformable mirror, a Kodak fast-framing intensified CCD camera, and a Mercury VME board containing four Intel i860 processors. The system has been tested using natural reference stars on the 40-inch Nickel telescope at Lick Observatory yielding up to a factor of 10 increase in image peak intensity and a… more

Date: March 1, 1994

Creator: Olivier, S. S.; An, J. & Avicola, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Simulation and analysis of laser guide star adaptive optics systems for the eight to ten meter class telescopes

This paper discusses the design and analysis of laser-guided adaptive optic systems for the large, 8--10 meter class telescopes. We describe a technique for calculating the expected modulation transfer function and the point spread function for a closed loop adaptive optics system, parameterized by the degree of correction and the seeing conditions. The results agree closely with simulations and experimental data, and validate well known scaling law models even at low order correction. Scaling … more

Date: March 1, 1994

Creator: Gavel, D. T. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Initial results from the Lick Observatory laser guide star adaptive optics system

We present initial results from the sodium-layer laser guide star adaptive optics system developed for the 3-m Shane telescope at Lick Observatory.

Date: June 9, 1995

Creator: Olivier, S. S.; An, Jong & Avicola, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Performance of laser guide star adaptive optics at Lick Observatory

A sodium-layer laser guide star adaptive optics system has been developed at Lawrence Livermore National Laboratory (LLNL) for use on the 3-meter Shane telescope at Lick Observatory. The system is based on a 127-actuator continuous-surface deformable mirror, a Hartmann wavefront sensor equipped with a fast-framing low-noise CCD camera, and a pulsed solid-state-pumped dye laser tuned to the atomic sodium resonance line at 589 nm. The adaptive optics system has been tested on the Shane telescope … more

Date: July 19, 1995

Creator: Olivier, S. S.; An, J. & Avicola, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Near infra-red astronomy with adaptive optics and laser guide stars at the Keck Observatory

A laser guide star adaptive optics system is being built for the W. M. Keck Observatory`s 10-meter Keck II telescope. Two new near infra-red instruments will be used with this system: a high-resolution camera (NIRC 2) and an echelle spectrometer (NIRSPEC). The authors describe the expected capabilities of these instruments for high-resolution astronomy, using adaptive optics with either a natural star or a sodium-layer laser guide star as a reference. They compare the expected performance of th… more

Date: August 3, 1995

Creator: Max, C. E.; Gavel, D. T. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Performance predictions for the Keck telescope adaptive optics system

The second Keck ten meter telescope (Keck-11) is slated to have an infrared-optimized adaptive optics system in the 1997--1998 time frame. This system will provide diffraction-limited images in the 1--3 micron region and the ability to use a diffraction-limited spectroscopy slit. The AO system is currently in the preliminary design phase and considerable analysis has been performed in order to predict its performance under various seeing conditions. In particular we have investigated the point-… more

Date: August 7, 1995

Creator: Gavel, D. T. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Initial results from the Lick Observatory Laser Guide Star Adaptive Optics System

A prototype adaptive optics system has been installed and tested on the 3 m Shane telescope at Lick Observatory. The adaptive optics system performance, using bright natural guide stars, is consistent with expectations based on theory. A sodium-layer laser guide star system has also been installed and tested on the Shane telescope. Operating at 15 W, the laser system produces a 9th magnitude guide star with seeing-limited size at 589 nm. Using the laser guide star, the adaptive optics system ha… more

Date: November 8, 1995

Creator: Olivier, S. S.; An, J. & Avicola, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Direct imaging of extra-solar planets

Direct imaging of extra-solar planets may be possible with the new generation of large ground-based telescopes equipped with state- of- the-art adaptive optics (AO) systems to compensate for the blurring effect of the Earth`s atmosphere. The first of these systems is scheduled to begin operation in 1998 on the 10 in Keck II telescope. In this paper, general formulas for high-contrast imaging with AO systems are presented and used to calculate the sensitivity of the Keck AO system. The results o… more

Date: March 1, 1997

Creator: Olivier, S. S.; Max, V. E.; Brase, J. M.; Caffano, C. J.; Gavel, D. T. & Macintosh, B. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

First significant image improvement from a sodium-layer laser guide star adaptive optics system at Lick Observatory

Atmospheric turbulence severely limits the resolution of ground-based telescopes. Adaptive optics can correct for the aberrations caused by the atmosphere, but requires a bright wavefront reference source in close angular proximity to the object being imaged. Since natural reference stars of the necessary brightness are relatively rare, methods of generating artificial reference beacons have been under active investigation for more than a decade. In this paper, we report the first significant i… more

Date: July 14, 1997

Creator: Olivier, S. S.; Max, C. E.; Friedman, H. W.; An, J.; Avicola, K.; Beeman, B. V. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Phase retrieval for adaptive optics system calibration

Our objective in this report is to develop methods to determine the output pupil wavefront using intensity measurements directly from the science detector. This wavefront can then be used to determine a reference wavefront which will precorrect for the non-common-path aberrations and produce the desired wavefront at the science detector. We describe two phase retrieval algorithms that can be used and a set of simulation studies of AO system calibration. We present the initial experimental resul… more

Date: August 1, 1997

Creator: Brase, J. M.; Carrano, C. J.; Macintosh, B. A.; Olivier, S. S. & An, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Observing techniques for astronomical laser guide star adaptive optics

We discuss astronomical observing requirements and their implementation using sodium-layer laser guide star adaptive optics. Specific issues requiring implementation include the ability to place the astronomical object at different locations within the field of view; reliable subtraction of Rayleigh-scattered light; efficient focusing; and stable point-spread-function characterization.

Date: May 1, 1998

Creator: Max, C. E.; Macintosh, B.; Olivier, S. S.; Gavel, D. T. & Friedman, H. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High-accuracy calibration of an adaptive optics system using a phase shifting diffraction interferometer

A phase-shifting diffraction interferometer (PSDI) has been integrated into an adaptive optics (AO) system developed by LLNL for use on the three meter Shane telescope at Lick Observatory. The interferometer is an all fiber optic design, which is extremely compact. It is useful for calibrating the control sensors, measuring the aberrations of the entire AO optical train, and measuring the influence functions of the individual actuators on the deformable mirror. The PSDI is particularly well sui… more

Date: June 23, 1999

Creator: Bauman, B. J.; Campbell, E. W.; Olivier, S. S. & Sweider, D. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

High-resolution wavefront control using liquid crystal spatial light modulators

Liquid crystal spatial light modulator technology appropriate for high-resolution wavefront control has recently become commercially available. Some of these devices have several hundred thousand controllable degrees of freedom, more than two orders of magnitude greater than the largest conventional deformable mirror. We will present results of experiments to characterize the optical properties of these devices and to utilize them to correct aberrations in an optical system. We will also presen… more

Date: July 20, 1999

Creator: Bauman, B. J.; Brase, J. M.; Brown, C. G.; Cooke, J. B.; Kartz, M. W.; Olivier, S. S. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Improved performance of the laser guide star adaptive optics system at Lick Observatory

Results of experiments with the laser guide star adaptive optics system on the 3-meter Shane telescope at Lick Observatory have demonstrated a factor of 4 performance improvement over previous results. Stellar images recorded at a wavelength of 2 {micro}m were corrected to over 40% of the theoretical diffraction-limited peak intensity. For the previous two years, this sodium-layer laser guide star system has corrected stellar images at this wavelength to {approx}10% of the theoretical peak inte… more

Date: July 20, 1999

Creator: An, J. R.; Avicola, K.; Bauman, B. J.; Brase, J. M.; Campbell, E. W.; Carrano, C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Progress with the lick adaptive optics system

Progress and results of observations with the Lick Observatory Laser Guide Star Adaptive Optics System are presented. This system is optimized for diffraction-limited imaging in the near infrared, 1-2 micron wavelength bands. We describe our development efforts in a number of component areas including, a redesign of the optical bench layout, the commissioning of a new infrared science camera, and improvements to the software and user interface. There is also an ongoing effort to characterize th… more

Date: March 1, 2000

Creator: Gavel, D T; Olivier, S S; Bauman, B; Max, C E & Macintosh, B

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fast Fourier and Wavelet Transforms for Wavefront Reconstruction in Adaptive Optics

Wavefront reconstruction techniques using the least-squares estimators are computationally quite expensive. We compare wavelet and Fourier transforms techniques in addressing the computation issues of wavefront reconstruction in adaptive optics. It is shown that because the Fourier approach is not simply a numerical approximation technique unlike the wavelet method, the Fourier approach might have advantages in terms of numerical accuracy. However, strictly from a numerical computations viewpoi… more

Date: July 28, 2000

Creator: Dowla, F. U.; Brase, J. M. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Adaptive optics for improved retinal surgery and diagnostics

It is now possible to field a compact adaptive optics (AO) system on a surgical microscope for use in retinal diagnostics and surgery. Recent developments in integrated circuit technology and optical photonics have led to the capability of building an AO system that is compact and significantly less expensive than traditional AO systems. It is foreseen that such an AO system can be integrated into a surgical microscope while maintaining a package size of a lunchbox. A prototype device can be de… more

Date: August 21, 2000

Creator: Humayun, M. S.; Sadda, S. R.; Thompson, C. A.; Olivier, S. S. & Kartz, M. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Adaptive Optics Survey for Companions to stars with Extra-Solar Planets

We have undertaken an adaptive optics imaging survey of extrasolar planetary systems and stars showing interesting radial velocity trends from high precision radial velocity searches. Adaptive Optics increases the resolution and dynamic range of an image, substantially improving the detectability of faint close companions. This survey is sensitive to objects less luminous than the bottom of the main sequence at separations as close as 1 inch. We have detected stellar companions to the planet be… more

Date: November 27, 2000

Creator: Lloyd, J. P.; Liu, M. C.; Graham, J. R.; Enoch, M.; Kalas, P.; Marcy, G. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

An Adaptive Optics Survey for Companions to Stars with Extra-Solar Planets

Date: November 27, 2000

Creator: Lloyd, J. P.; Liu, M. C.; Graham, J. R.; Enoch, M.; Kalas, P.; Marcy, G. W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Advanced Wavefront Control Techniques

Programs at LLNL that involve large laser systems--ranging from the National Ignition Facility to new tactical laser weapons--depend on the maintenance of laser beam quality through precise control of the optical wavefront. This can be accomplished using adaptive optics, which compensate for time-varying aberrations that are often caused by heating in a high-power laser system. Over the past two decades, LLNL has developed a broad capability in adaptive optics technology for both laser beam con… more

Date: February 21, 2001

Creator: Olivier, S. S.; Brase, J. M.; Avicola, K.; Thompson, C. A.; Kartz, M. W.; Winters, S. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Initial Performance of the Keck AO Wavefront Controller System

The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control loop to remove tilt from the incoming wavefront, and a deformable mirror control loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from t… more

Date: March 1, 2001

Creator: Johansson, E. M.; Acton, D. S.; An, J. R.; Avicola, K.; Beeman, B. V.; Brase, J. M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department