Honeywell International Inc.

United States of America As Represented by the Secretary of the Air Force

Subash Krishnankutty

Barrett E Cole

Robert E Higashi

Wei Yang

Christopher J Zins

Thomas E Nohava

Scott A McPherson

Arunkumar Subramanian

Robert C Torreano

Holly A Marsh

Aravind Padmanabhan

Robert D Horning

Brian C Krafthefer

Mike E Bazakos

Wing Au

P Paul Ruden

A multi-substrate package assembly having a first substrate, a second substrate and a package, each with a number of bond pads. The package includes a cavity for receiving either or both of the first and second substrates, with a number of bond pads positioned along at least part of the periphery of the cavity. The first substrate and the second substrate are preferably positioned in the cavity of the package, with selected bond pads of the first substrate and second substrate electrically connected to selected bond pads of the package. In some embodiments, the bond pads of the first substrate are only connected to bond pads on one or more sides of the cavity, and the bond pads of the second substrate are only connected to bond pads on one or more of the remaining sides of the cavity. The packaging assembly of the present invention can be used in many applications, including spectrally tunable optical detectors.

Multi-substrate package assembly

A spectrally tunable optical detector and methods of manufacture therefore are provided. In one illustrative embodiment, the tunable optical detector includes a tunable bandpass filter, a detector and readout electronics, each supported by a different substrate. The substrates are secured relative to one another to form the spectrally tunable optical detector.

Spectrally tunable detector

A sensor network provides the ability to detect, classify and identify a diverse range of agents over a large area, such as a geographical region or building. The network possesses speed of detection, sensitivity, and specificity for the diverse range of agents. Different functional level types of sensors are employed in the network to perform early warning, broadband detection and highly specific and sensitive detection. A high probability of detection with low probability of false alarm is provided by the processing of information provided from multiple sensors. A Bayesian net is utilized to combine probabilities from the multiple sensors in the network to reach a decision regarding the presence or absence of a threat. The network is field portable and capable of autonomous operation. It also is capable of providing automated output decisions.

Architectures of sensor networks for biological and chemical agent detection and identification

A tunable filter having a top mirror, a bottom mirror, and one or more intervening layers. The one or more intervening layers preferably have a refractive index that changes with temperature. By heating the one or more intervening layers, the wavelength that is selected by the optical filter can be controlled. The one or more intervening layers are preferably heated by passing current through the one or more intervening layers, or by passing current through a separate resistive layer that is thermally coupled to the one or more intervening layers. Such a filter can provide a high degree of wavelength selectivity in a robust and stable manner.

Tunable optical filter

A p-i-n photodiode having a high responsivity and quantum efficiency due to an AlGaN heterojunction where photons are absorbed within the p-n junction thereby eliminating carrier losses due to surface recombination and diffusion processes. Ultraviolet light comes through a transparent substrate, such as sapphire, a transparent AlN buffer and an n-doped AlGaN layer, and to an undoped AlGaN layer where the light is absorbed. The undoped layer is sandwiched between the n-doped AlGaN layer and a p-doped AlGaN layer. Metal contacts are formed on the doped layers to obtain the current caused by the absorbed light in the undoped layer. The mole fractions of the Al and Ga in the undoped and doped layers may be adjusted to obtain a desired wavelength bandpass of light to be detected.

Back-illuminated heterojunction photodiode

A semiconductor material avalanche photodiode photodetector having ultraviolet response, solar radiation immunity and response speed in excess of that available from conventional ultraviolet photodetectors is described. The detector is an avalanche photodiode comprised of periodic table group III-Nitride semiconductor material, such as aluminum gallium nitride, serving as a photon to charge carrier transducer, and an avalanche charge carrier multiplication region comprised of different semiconductor materials such as silicon. The photodetector is capable of selective ultraviolet signal transducing while exposed to a mixture of ultraviolet and solar energy &ldquo;noise&rdquo; radiation. The included avalanche multiplication region is optically shielded from solar and other energy components to enable this selective capability. A multiplied ultraviolet photoresponsive electric signal is collected from output electrodes disposed adjacent the avalanche multiplication structure. Two physical arrangements of the detector are included.

Hybrid ultraviolet detector

A GaN/AlGaN heterojunction bipolar phototransistor having AlGaN contact, i-GaN absorbing, p-GaN base and n-GaN emitter layers formed, in that order, on a UV transparent substrate. The phototransistor has a gain greater than 10.sup.5. From 360 nm to 400 nm, eight orders of magnitude drop in responsivity was achieved. The phototransistor features a rapid electrical quenching of persistent photoconductivity, and exhibits high dark impedance and no DC drift. By changing the frequency of the quenching cycles, the detection speed of the phototransistor can be adjusted to accommodate specific applications. These results represent an internal gain UV detector with significantly improved performance over GaN based photo conductors.

Growing community of inventors

North Haven, CT, United States of America

Subash Krishnankutty