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Honeywell has developed a high-speed infrared emitter pixel and implemented the design on two 512 X 512 scene projector array designs. This pixel is a faster version of the original Gen-III Gossamer pixel implemented on previous 512 X 512 arrays. The new pixel has a 10% - 90% rise time under 4 milliseconds, enabling a dramatic increase in scene projection frame rates over currently available arrays. Full array frame rates of 200 Hz are not practical and subarrays can be driven up to 400 Hz. In spite of the increased speed, the array still maintains high brightness using the same CMOS electronics. This design and other array developments will be described.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In the past year, Honeywell has developed a 512 X 512 snapshot scene projector containing pixels with very high radiance efficiency. The array can operate in both snapshot and raster mode. The array pixels have near black body characteristics, high radiance outputs, broad band performance, and high speed. IR measurements and performance of these pixels will be described. In addition, a vacuum probe station that makes it possible to select the best die for packaging and delivery based on wafer level radiance screening, has been developed and is in operation. This system, as well as other improvements, will be described. Finally, a review of the status of the present projectors and plans for future arrays is included.

In 1991 the Honeywell Technology Center began the development of large area 2D microemitter arrays for IR scene projection. Since then, 5 different types of 512 X 512 or larger arrays have been fabricated, all in current use. This paper will review the status, properties, and applications of these arrays. Pixel and array improvements which will lead to ultralow power consumption, very high performance, very fast 1024 square arrays are under development. A number of these efforts are described.

Resistive emitter arrays are formed via the fabrication of microemitters on Si CMOS electronics. These IR emitter arrays using microstructures have been developed at Honeywell to project scenes for a wide range of applications. A new array which has been fabricated has a size of 544 X 672 pixels. Other arrays producing very high apparent temperatures in excess of 700 K have also been fabricated. Arrays have been fabricated for projecting low background scenes achieved through cryogenic operation. All arrays are designed to project IR radiation over the full MWIR and LWIR spectral bands. Individual arrays and their emission properties will be described. Array properties at different substrate temperatures will be described. Advances in packaging of these different array types will also be discussed.

An addressable mosaic array of resistively heated microbridges offers the potential to project accurate dynamic infrared (IR) imagery. The main purpose of this imagery is to be used in the evaluation of IR instruments from seekers to FLIRs. With the growing development of lower cost uncooled IR imagers, scene projectors also offer the potential for dynamic testing of these new instruments. In past years we have described developments in a variety of IR projectors systems designed for different purposes. In this paper we will describe recent developments in these technologies aimed at improving or understanding temporal and radiative performance.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An addressable mosaic array of resistively heated microbridges offers much flexibility for infrared scene simulations. In the Wide Band Infrared Scene Projector program, Honeywell has demonstrated high yield arrays up to size 512 X 512 capable of room temperature operation for a 2 band infrared projection system being designed and built by Contraves Inc. for the Wright Laboratory Kinetic Kill Vehicle Hardware In-the-Loop Simulator facility at Eglin Air Force Base, FL. The arrays contain two different pixel designs, one pixel designed for kHz frame rates and high radiance achieved at a power level of 2.5 mWatts/pixel and the other pixel designed for more moderate 100 Hz frame rates at lower radiance and at maximum power levels of 0.7 mWatts/pixels. Tests on arrays and pixels have demonstrated dynamic ranges up to 850:1, radiance rise times on the order of 2 mseconds, and broadband pixel emissivities in the range of 70%. Arrays have been fabricated with less than 0.1% pixel outages and no row or column defects. These arrays are mounted in a specialized vacuum assembly containing an IR window, vacuum package, cooling block, and pump out manifold.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A mosaic array of resistively heated microbridges offers flexibility for infra red scene simulations. The array may operate without flicker and display high-intensity dynamic scenes over a wide bandwidth. Honeywell completed fabrication of a 512 X 512 resistor array with 3.5 mils pitch for AEDC's 7V and 10V test chambers. The emitter has a broad bandwidth covering from 2 micrometers to 26 micrometers . The array operates at 20 K to simulate low radiation backgrounds in space. Up to 16,000 pixels may be turned on to simulate targets and target clusters. Each emitter element may heat up to 550 K with 1 kelvin resolution. The maximum power dissipation per pixel is 830 (mu) W for a pixel heated up to 550 K. The maximum power required is 13.2 watts for 16,000 pixels. This low power capability is derived from Honeywell's silicon nitride microbridge structure. Each emitter has approximately 85% fill factor and an average emissivity of 70% over the 2 - 26 micrometers bandwidth. Defect count in the array is less than 1% with one column out. The array may be addressed at 30 frames per second.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A silicon microstructure airflow sensor has been developed with a wide dynamic operating range and ruggedness for long-life operation in harsh environments. Platinum metallization is used for the airflow sensor because of its resistance to corrosion. Processing of thin-film platinum has been developed to achieve a high, stable value of the platinum temperature coefficient of resistance (TCR). The sensor design can be adjusted for sensitivity or range depending upon the application requirements. The airflow sensors were subjected to accelerated life testing to demonstrate the ability to maintain electrical stability and physical integrity in harsh environments. The life testing consisted of operation of the sensors with airflow in overpowered, high-temperature, and high-humidity conditions for extended periods. The sensors were also subjected to extended periods of time during which dust particles were added to the flow to simulate a dusty environment. The sensors performed well throughout the accelerated life testing with little change in output characteristics. >

Results are presented which identify a dominant aging mechanism of plated-wire memory elements in the absence of magnetic fields. This mechanism, i.e., stress relief in the Permalloy film, can occur even in elements stabilized against field-induced aging. The evidence for stress relief consists of aging and strain sensitivity measurements on samples of different Permalloy composition. In aging experiments under vacuum at 230°C, Ni-rich films show an increase in anisotropy field H k , while Fe-rich films show a decrease. A stress relief model is described which relates such aging changes to the initial film stress the cylindrical geometry, and the tension strain sensitivity. Using this model, agreement is found between film stress deduced from the H k aging changes, and film stress from direct measurements, reported in the literature. Films which are judged to have zeromagnetostrictive composition (ZMC) on the basis of torsion sensitivity are found to show nonzero tension sensitivity. This is satisfactorily accounted for by circumferential composition inhomogeneity, which is shown analytically to explain the observed decrease in anisotropy field with tension. It is concluded that reduction of such inhomogeneity by appropriate deposition techniques is favorable to both smaller strain sensitivity and increased aging stability.

Switching thresholds of plated wires were determined with slowly applied external magnetic fields, using both torquemeter and ac techniques. The samples included wires having helical easy-direction angles of 0°, 24°, 30°, and 60°. A study was made of the dependence of switching threshold H C on the angle θ between applied field and wire axis. Good agreement was found with the relation H_{C}(\theta)=H_{C}(0)/\cos \theta for all helical angles and for θ as high as 85°. It is concluded that with the cylindrical film geometry only the axial component of external field is effective in quasi-static switching over wide ranges of field direction and helical angle.

Amorphous Gd-Co films sputtered at substrate biases ≤100V showed compensation temperature differences of about 100°C between the film-glass (FG) and film-air (FA) surfaces, as measured by Kerr rotation. The films exhibited normal as well as inverted Kerr and Hall loops, but throughout the temperature range between compensation temperatures either the FG or FA surface, but not both, showed inverted Kerr loops. Inversion temperatures were found at which the inverted loop property was transferred from one film surface to the other. Biased loops were obtained from inverted loops by reducing the field amplitude in one polarity. The bias field, H B , was identified as the effective field of exchange-coupled Gd-Rich and Co-rich layers. By the use of H B data the interlayer wall energy density was estimated to be 0.9 ±0.2 ergs cm-2.