California Institute of Technology

United States of America As Represented by the Administrator of Nasa

Daniel W Wilson

Sarath D Gunapala

Sumith V Bandara

John K Liu

Richard E Muller

Gregory H Bearman

William R Johnson

Morteza Gharib

Dominique Claire Fourguette

Darius Modarress

Frederic Taugwalder

Paul D Maker

William J Parrish

Frank Greer

Karl Y Yee

Cecile D Jung-Kubiak

Siamak Forouhar

Victor E White

Matthew R Dickie

James E Polk

Pantazis Mouroulis

Colleen M Marrese-Reading

John R Anderson

Nima Rouhi

Micro-emitter arrays and methods of microfabricating such emitter arrays are provided. The microfabricated emitter arrays incorporate a plurality of emitters with heights greater than 280 microns with uniformity of +/&#x2212;10 microns arranged on a supporting silicon substrate, each emitter comprising an elongated body extending from the top surface of the substrate and incorporating at least one emitter tip on the distal end of the elongated body thereof. The emitters may be disposed on the substrate in an ordered array in an X by Y grid pattern, wherein X and Y can be any number greater than zero. The micro-emitter arrays may utilize a LMIS propellant source including, for example, gallium, indium, bismuth, or tin. The substrate may incorporate at least one through-via providing a fluid pathway for the LMIS propellant to flow from a propellant reservoir beneath the substrate to the top substrate surface whereupon the micro-emitter array is disposed.

Micro-emitters for electrospray systems

Computed tomography imaging spectrometers ('CTISs') employing a single lens are provided. The CTISs may be either transmissive or reflective, and the single lens is either configured to transmit and receive uncollimated light (in transmissive systems), or is configured to reflect and receive uncollimated light (in reflective systems). An exemplary transmissive CTIS includes a focal plane array detector, a single lens configured to transmit and receive uncollimated light, a two-dimensional grating, and a field stop aperture. An exemplary reflective CTIS includes a focal plane array detector, a single mirror configured to reflect and receive uncollimated light, a two-dimensional grating, and a field stop aperture.

Single-lens computed tomography imaging spectrometer and method of capturing spatial and spectral information

Computed tomography imaging spectrometers ('CTIS's) having color focal plane array detectors are provided. The color FPA detector may comprise a digital color camera including a digital image sensor, such as a Foveon X3&#xae; digital image sensor or a Bayer color filter mosaic. In another embodiment, the CTIS includes a pattern imposed either directly on the object scene being imaged or at the field stop aperture. The use of a color FPA detector and the pattern improves the accuracy of the captured spatial and spectral information.

Color camera computed tomography imaging spectrometer for improved spatial-spectral image accuracy

Computed tomography imaging spectrometers ('CTIS's) having patterns for imposing spatial structure are provided. The pattern may be imposed either directly on the object scene being imaged or at the field stop aperture. The use of the pattern improves the accuracy of the captured spatial and spectral information.

Spatial image modulation to improve performance of computed tomography imaging spectrometer

Quantum-well sensors having an array of spatially separated quantum-well columns formed on a substrate. A grating can be formed increase the coupling efficiency.

Quantum well sensor having spatially separated sensing columns

A diffractive optic sheer stress sensor operates by forming diverging fringes over a linear area of measurement. A diode laser focuses light onto a diffractive lens which focuses the light to respective slits. The slits form diverging fringes, and scattered light from the fringes is collected by a window and focused by another diffractive lens to a receiver.

Diffractive optical fluid shear stress sensor

An optical particle detection system produces an optical beam which is scattered by particles in a probe volume area. The particles may scatter the beam to the detector. The optical beam is a hollow shaped beam which may be circular/doughnut shaped, or made be of any other hollow shape. The particle passes across the beam, and those particles which pass through the center of the beam are detected as being desired particles to detect. This system may be used to detect particle concentration, and size. In addition, by producing an asymmetric beam, particle direction can also be detected.

Particle sizing and concentration sensor using a hollow shaped beam

The optical system of this invention is an unique type of imaging spectrometer, i.e. an instrument that can determine the spectra of all points in a two-dimensional scene. The general type of imaging spectrometer under which this invention falls has been termed a computed-tomography imaging spectrometer (CTIS). CTIS's have the ability to perform spectral imaging of scenes containing rapidly moving objects or evolving features, hereafter referred to as transient scenes. This invention, a reflective CTIS with an unique two-dimensional reflective grating, can operate in any wavelength band from the ultraviolet through long-wave infrared. Although this spectrometer is especially useful for rapidly occurring events it is also useful for investigation of some slow moving phenomena as in the life sciences.

Computed tomography imaging spectrometer (CTIS) with 2D reflective grating for ultraviolet to long-wave infrared detection especially useful for surveying transient events

A three-color QWIP focal plane array is based on a GaAs/AlGaAs material system. Three-color QWIPs enable target recognition and discriminating systems to precisely obtain the temperature of two objects in the presence of a third unknown parameter. The QWIPs are designed to reduce the normal reflection over a significant wavelength range. One aspect of the present invention involves two photon absorptions per transition in a double quantum well structure which is different from typical QWIP structures. This design is expected to significantly reduce the dark current as a result of higher thermionic barriers and therefore allow the devices to operate at elevated temperatures. The device is expected to be fabricate using a GaAs/Al Ga As material system on a semi-insulating GaAs substrate by Molecular Beam Epitacy (MBE).

Three color quantum well infrared photodetector focal plane array

The present disclosure describes a technique for creating diffraction gratings on curved surfaces with electron beam lithography. The curved surface can act as an optical element to produce flat and aberration-free images in imaging spectrometers. In addition, the fabrication technique can modify the power structure of the grating orders so that there is more energy in the first order than for a typical grating. The inventors noticed that by using electron-beam lithography techniques, a variety of convex gratings that are well-suited to the requirements of imaging spectrometers can be manufactured.

Diffractive optical elements on non-flat substrates using electron beam lithography

Techniques for coupling radiation into a quantum-well detector by using a two-dimensional array of grating cells to form at least three different grating directions to provide efficient coupling.

Growing community of inventors

Montrose, CA, United States of America

Daniel W Wilson