We have designed a new near-IR imaging polarimeter which generates the complete Stokes' vector estimation
simultaneously. The design is based on our first generation division of amplitude polarimeter where four images are
folded on to a single focal plane detector. This gives rise to a small compact rigid instrument. The design operation
wavelength is 632.8 nanometers. The new second generation design operates at a wavelength of 1550 nanometers and
has three improvements over the first generation: 1) the design of the Beam-Splitter Assembly (BSA) is based on an
optimization scheme where the Measurement (instrument) matrix is optimized for Stokes' vector estimation with noisy
data, 2) the four individual focusing lenses positioned after the BSA have been replaced by a single lens in front of the
BSA reducing differential image distortion, and 3) a reticle is placed at an intermediate image plane, providing a fiducial
mark in each of the images for precise registration.
The Lockheed Martin - University of Arizona Infrared Spectrometer (LAIRS) is designed to image the emission
lines of celestial objects in the 1.3-2.5 μm regime. The Instrument has been built and tested at the Lockheed
Martin Space Systems Advanced Technology Center, and demonstrated to work at cryogenic
temperatures. The Instrument employs a tunable Fabry-Perot Interferometer (FPI) to select the wavelength at
which the Instrument images targets. The FPI employs voice coil actuators and capacitive sensors to maintain
parallelism of its reflective lenses and control their gap spacing. During functional tests of the FPI and the
LAIRS instrument, finesse numbers of 60 and 24 were measured for the interferometer at room temperature
and 80K, respectively. This measurement was performed using a laser operating at 1529.33 nm. This paper
presents an overview of the optical, mechanical, and control design of the FPI, as well as a summary of cryogenic
Lockheed Martin is developing an innovative and adaptable optical telescope comprised of an array of nine identical afocal sub-telescopes. Inherent in the array design is the ability to perform high-resolution broadband imaging, Fizeau Fourier transform spectroscopy (FTS) imaging, and single exposure multi-spectral and polarimetric imaging. Additionally, the sensor suite's modular design integrates multiple science packages for active and passive sensing from 0.4 to 14 microns. We describe the opto-mechanical design of our concept, the Multiple Instrument Distributed Aperture Sensor (MIDAS), and a selection of passive and active remote sensing missions it fulfills.
Adaptive optics correct light wavefront distortion caused by atmospheric turbulence or internal heating of optical components. This distortion often limits performance in ground-based astronomy, space-based earth observation and high energy laser applications. The heart of the adaptive optics system is the deformable mirror. In this study, an electromechanical model of a deformable mirror was developed as a design tool. The model consisted of a continuous, mirrored face sheet driven with multilayered, electrostrictive actuators. A fully coupled constitutive law simulated the nonlinear, electromechanical behavior of the actuators, while finite element computations determined the mirror's mechanical stiffness observed by the array. Static analysis of the mirror/actuator system related different electrical inputs to the array with the deformation of the mirrored surface. The model also examined the nonlinear influence of internal stresses on the active array's electromechanical performance and quantified crosstalk between neighboring elements. The numerical predictions of the static version of the model agreed well with experimental measurements made on an actual mirror system. The model was also used to simulate the systems level performance of a deformable mirror correcting a thermally bloomed laser beam. The nonlinear analysis determined the commanded actuator voltages required for the phase compensation and the resulting wavefront error.
This paper describes an integrated nondestructive inspection framework that has been developed, under DARPA sponsorship, to meet the joint needs of optical design, high quality manufacturing and operational integrity monitoring that is both pragmatic and affordable. These needs stem form fiscal and regulatory drivers that mandate affordable hazard analysis and risk mitigation in both commercial and defense sectors. The framework features standardization of data formats for easy data exchange, automated data processing via the Internet, geographically remote data archiving and killer application interconnects, all tied in to user tailored conventional workstation interfaces. The effectiveness of this framework is demonstrated by an exemplar that is based on investment casing of gas turbine blades exploiting x-ray CT inspection, reverse CAD image processing and multimodal data fusion.
This paper describes the experimental verification of a technique to ensure that the raw sensor data base meets integrity confidence levels required for initiating critical operating decisions associated with aircraft structures. Neural Network techniques are used to characterize the spectral response of sensor arrays to known sensor faults, thus discriminating between structural and sensor anomalies.