Keyword: Mirrors

Briefs: Physical Sciences
Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be...

Briefs: Software
JWST Wavefront Control Toolbox

A Matlab-based toolbox has been developed for the wavefront control and optimization of segmented optical surfaces to correct for possible misalignments of James Webb Space Telescope (JWST) using influence functions. The toolbox employs both iterative and non-iterative methods to converge to an optimal solution by...

Briefs: Mechanical & Fluid Systems
Cryogenic Scan Mechanism for Fourier Transform Spectrometer

A compact and lightweight mechanism has been developed to accurately move a Fourier transform spectrometer (FTS) scan mirror (a cube corner) in a near-linear fashion with near constant speed at cryogenic temperatures. This innovation includes a slide mechanism to restrict motion to one...

Briefs: Manufacturing & Prototyping
Nanoscale Deformable Optics

Several missions and instruments in the conceptual design phase rely on the technique of interferometry to create detectable fringe patterns. The intimate emplacement of reflective material upon electron device cells based upon chalcogenide material technology permits high-speed, predictable deformation of the...

Briefs: Physical Sciences
Extracting Zero-Gravity Surface Figure of a Mirror

The technical innovation involves refinement of the classic optical technique of averaging surface measurements made in different orientations with respect to gravity, so the effects of gravity cancel in the averaged image. Particularly for large, thin mirrors subject to substantial deformation,...

Briefs: Information Technology
Comparison of Aircraft Icing Growth Assessment Software

A research project is underway to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the...

Briefs: Physical Sciences
Null Lens Assembly for X-Ray Mirror Segments

A document discusses a null lens assembly that allows laser interferometry of 60° slumped glass mirror segments used in x-ray mirrors. The assembly consists of four lenses in precise alignment to each other, with incorporated piezoelectric nanometer stepping actuators to position the lenses in six...

Application Briefs: Photonics/Optics

To decode the human genome and gain a greater understanding of diseases and their aetiology, advances need to be made in the rate at which the nucleotides that comprise DNA can be...

Briefs: Photonics/Optics

An analysis of the classical method of calculating the zero-gravity surface figure of a mirror from surface-figure measurements in the presence of gravity has led to improved...

Briefs: Physical Sciences
Hybrid Architecture Active Wavefront Sensing and Control

A method was developed for performing relatively high-speed wavefront sensing and control to overcome thermal instabilities in a segmented primary mirror telescope [e.g., James Webb Space Telescope (JWST) at L2], by using the onboard fine guidance sensor (FGS) to minimize expense and...

Briefs: Physical Sciences
Inductive Non-Contact Position Sensor

Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter’s windows. In this hardware, a mirror is translated such that its position corresponds to the defect’s depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is...

Briefs: Mechanical & Fluid Systems
Heterodyne Interferometer Angle Metrology

A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The commonpath heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the...

Briefs: Physical Sciences
Focusing Diffraction Grating Element With Aberration Control

Diffraction gratings are optical components with regular patterns of grooves, which angularly disperse incoming light by wavelength in a single plane, called dispersion plane. Traditional gratings on flat substrates do not perform wavefront transformation in the plane perpendicular to...

Briefs: Physical Sciences

This software has been designed to detect water bodies that are out in the open on cross-country terrain at mid- to far-range (approximately 20–100 meters), using imagery acquired from a stereo pair...

Briefs: Physical Sciences
Mode Tracker for Mode-Hop-Free Operation of a Laser

A mode-tracking system that includes a mode-controlling subsystem has been incorporated into an external-cavity (EC) quantum cascade laser that operates in a mid-infrared wavelength range. The mode-tracking system makes it possible to perform mode-hop-free wavelength scans, as needed for...

Briefs: Physical Sciences

The optical pointing sensor provides a means of directly measuring the relative positions of JPL’s Formation Control Testbed (FCT) vehicles without communication. This innovation is a steerable infrared (IR)...

Briefs: Physical Sciences
Nanolaminate Membranes as Cylindrical Telescope Reflectors

A document discusses a proposal to use axially stretched metal nanolaminate membranes as lightweight parabolic cylindrical reflectors in the Dual Anamorphic Reflector Telescope (DART) — a planned spaceborne telescope in which the cylindrical reflectors would be arranged to obtain a...

Briefs: Photonics/Optics
Large Telescope Segmented Primary Mirror Alignment

A document discusses a broadband (white light) point source, located at the telescope Cassegrain focus, which generates a cone of light limited by the hole in the secondary mirror (SM). It propagates to the aspheric null-mirror, which is optimized to make all the reflected rays to be normal to...

Application Briefs: Photonics/Optics
Widely Tunable Mode-Hop-Free External-Cavity Quantum Cascade Laser

The external-cavity quantum cascade laser (EC-QCL) system is based on an optical configuration of the Littrow type. It is a room-temperature, continuous- wave, widely tunable, mode-hop-free, mid-infrared, EC-QCL spectroscopic source. It has a single-mode tuning range of 155...

Application Briefs: Imaging
MEMS-based deformable mirrors
Boston Micromachines Corp.
Cambridge, MA
617-868-4178
www.bostonmicromachines.com

Boston Micromachines has been selected...

Briefs: Physical Sciences

An adaptive-nulling method has been proposed to augment the nulling-optical-interferometry method of detection of Earth-like planets around distant stars. The method is intended to...

Briefs: Materials
Electroceramic Actuators for Operation at Low Temperatures

Electrostrictive ceramic actuators that can function at low temperatures have been developed for controlling the shapes of mirrors in the Next Generation Space Telescope (NGST). On Earth, electrostrictive ceramic actuators may be useful for fine control of the positions of objects in...

Briefs: Physical Sciences

A method is proposed for end-toend, full aperture testing of large-aperture telescopes using an innovative variation of a Hartmann mask. This technique is practical for telescopes...

Briefs: Physical Sciences

White-light phase-conjugate mirrors would be incorporated into some optical systems, according to a proposal, as means of correcting for wavefront distortions caused by...

Briefs: Physical Sciences

Sub-aperture interferometers — also called wavefront-split interferometers — have been developed for simultaneously measuring displacements of multiple targets. The terms “sub-aperture” and...

Briefs: Physical Sciences
Ultra-Compact, High-Resolution LADAR System for 3D Imaging

An eye-safe LADAR system weighs under 500 grams and has range resolution of 1 mm at 10 m. This laser uses an adjustable, tiny microelectromechanical system (MEMS) mirror that was made in SiWave to sweep laser frequency. The size of the laser device is small (70×50×13 mm). The LADAR...

Briefs: Physical Sciences
Dual-Channel Multi-Purpose Telescope

A dual-channel telescope allows for a wide-field telescope design with a good, narrow field channel of fewer surfaces for shorter-wavelength or planet-finding applications. The design starts with a Korsch three-mirror-anastigmat (TMA) telescope that meets the mission criteria for image quality over a wide...

Briefs: Physical Sciences
Cryogenic Pupil Alignment Test Architecture for Aberrated Pupil Images

A document describes cryogenic test architecture for the James Webb Space Telescope (JWST) integrated science instrument module (ISIM). The ISIM element primarily consists of a mechanical metering structure, three science instruments, and a fine guidance sensor. One of the...

Briefs: Physical Sciences
Pixelized Device Control Actuators for Large Adaptive Optics

A fully integrated, compact, adaptive space optic mirror assembly has been developed, incorporating new advances in ultralight, high- performance composite mirrors. The composite mirrors use Q-switch matrix architecture- based pixelized control (PMN-PT) actuators, which achieve high-...