Massachusetts Institute of Technology

Sumanth Kaushik

Yaron Rachlin

Jerry C Chen

Charles Wynn

Ryan Sullenberger

Mohammad Jalal Khan

Melissa Alyson Smith

Mordechai Rothschild

Livia M Racz

Robert W Haupt

Stephen T Palmacci

Richard M Heinrichs

Jonathan Ashcom

Adam Milstein

Dennis Burianek

Kevin W Holman

David G Kocher

Jae H Kyung

Leaf A Jiang

A wafer-scale satellite bus and a manner of making the same include using wafer reconstruction techniques to stack functional diced circuits onto each other and bond them. The disclosed techniques allow for a variety of functions in each die, including providing, without limitation: ground-based communications, attitude and propulsion control, fuel tanks and thrusters, and power generation. The wafers are initially manufactured according to a common wafer design that provides electrical and power interconnects, then different wafers are further processed using subsystem-specific techniques. The circuits on differently-processed wafers are reconstructed into a single stack using e.g. wafer bonding. Surface components are mounted, and the circuitry is diced to form the final satellites. Mission-specific functions can be incorporated, illustratively by surface-mounting, to the bus at an appropriate stage of assembly, on-wafer circuitry or instrument packages for performing these functions.

Wafer-scale satellite with integrated propulsion and attitude control

The ability to communicate with a specific subject at a prescribed location who lacks any communications equipment opens up many intriguing possibilities. Communications across noisy rooms, hail and warn applications, and localized communications directed at only the intended recipient are a few possibilities. We disclose and show localized acoustic communications, which we call photoacoustic communications, with a listener at long standoff distances using a modulated laser transmitted toward the receiver's ear. The optically encoded information is converted into acoustic messages via the photoacoustic effect. The photoacoustic conversion of the optical information into an audible signal occurs via the absorption of the light by ambient water vapor in the near area of the receiver's ear followed by airborne acoustic transmission to the ear. The recipient requires no external communications equipment to receive audible messages.

Methods and apparatus for acoustic laser communications

Hyperspectral imaging spectrometers have applications in environmental monitoring, biomedical imaging, surveillance, biological or chemical hazard detection, agriculture, and minerology. Nevertheless, their high cost and complexity has limited the number of fielded spaceborne hyperspectral imagers. To address these challenges, the wide field-of-view (FOV) hyperspectral imaging spectrometers disclosed here use computational imaging techniques to get high performance from smaller, noisier, and less-expensive components (e.g., uncooled microbolometers). They use platform motion and spectrally coded focal-plane masks to temporally modulate the optical spectrum, enabling simultaneous measurement of multiple spectral bins. Demodulation of this coded pattern returns an optical spectrum in each pixel. As a result, these computational reconfigurable imaging spectrometers are more suitable for small space and air platforms with strict size, weight, and power constraints, as well as applications where smaller or less expensive packaging is desired.

Computational reconfigurable imaging spectrometer

A method and apparatus used for detecting gaseous chemicals. The method and apparatus use an interferometer to filter received light by wavelength, creating an image only using light with wavelengths that are affected by the presence of a gaseous chemical. A reference image composed of light with wavelengths unaffected by the presence of a gaseous chemical is also created and used as a reference. A gaseous chemical is detected where the ratio of the intensity of the two images changes. Despite the high spectral resolution of the filter, the system can operate with a very wide field of view.

Wide field of view narrowband imaging filter technology

An imaging apparatus and corresponding method according to an embodiment of the present invention enables high-resolution, wide-field-of-view, high sensitivity imaging. An embodiment of the invention is a camera system that utilizes motion of an optical element, such as a spatial filtering mask or of the camera itself, to apply different spatial filtering functions to a scene to be imaged. Features of a spatial filtering mask implementing the different filtering functions are adjacent along an axis of the spatial mask, and a pitch of the features of the mask is smaller than a pitch of the sensor elements. An imaging reconstructor having knowledge of the filtering functions can produce a high-resolution image from corresponding low-resolution coded imaging data captured by the imaging system. This approach offers advantages over conventional high-resolution, wide-field imaging, including an ability to use large-pitch, lower cost sensor arrays, and transfer and store much less data.

Method and apparatus for motion coded imaging

Disclosed herein are a system and corresponding method for sensing terahertz radiation. The system collects terahertz radiation scattered from a target and upconverts the collected radiation to optical frequencies. A frequency-domain spectrometer senses spectral components of the upconverted signal in parallel to produce a spectroscopic measurement of the entire band of interest in a single shot. Because the sensing system can do single-shot measurements, it can sense moving targets, unlike sensing systems that use serial detection, which can only be used to sense stationary objects. As a result, the sensing systems and methods disclosed herein may be used for real-time imaging, including detection of concealed weapons, medical imaging, and hyperspectral imaging.

Terahertz sensing system and method

A kit for detecting the presence of an explosive includes a pulsed focused energy source located at a target distance away from a substrate, the energy having a magnitude sufficient to release the internal energy of an explosive if present on the substrate and thereby generate an acoustic wave. The kit also includes a detector adapted to detect the acoustic wave at a detection distance away from the substrate.

Method and kit for stand-off detection of explosives

A time-multiplexed waveform generator includes a wavelength splitter that receives an input optical signal and spectrally separates the input optical signal into a plurality of frequency components. A plurality of intensity modulators receives each of the frequency components and passes each of the frequency components for a selective time period, and then extinguishes that frequency for the remainder of a chirp time, the plurality of intensity modulators producing a plurality of first output signals. A plurality of adjustable delay lines is positioned after the intensity modulators and receives the first output signals. Each of the adjustable delay lines enables phase control of each of the frequency components associated with the first output signals for compensating any relative drifts of the path lengths and phase coherently stitching a plurality of sub-chirps together. The adjustable delay lines produce a plurality of second output signals. A wavelength combiner receives the second output signals and recombines the output signals to produce a stair-step waveform output signal.

Time-multiplexed optical waveform generation

Described are a sensor and a method for measuring a vibration of a surface obscured from view. The sensor includes a narrowband source of a terahertz beam, a beamsplitter, a beam combiner and a terahertz detector. The beamsplitter splits the terahertz beam into a sample beam for irradiating the surface and a reference beam. The beam combiner combines the sample beam scattered from the surface and the reference beam. The terahertz detector generates an electrical signal based on a modulation of the power of the combined beams due to the vibrating surface. The electrical signal indicates a characteristic of the surface vibration. Homodyne or heterodyne detection can be utilized. Advantageously, the sensor can see surfaces that are covered, concealed or otherwise obscured behind optically opaque materials, including plastic, cloth, foam, paper and other materials. Thus the sensor has a wide variety of applications where conventional vibrometers are not practical.

Sensor for measuring a vibrating surface obscured from view

High bandwidth angle modulated communications may be obtained using an incoherent/broadband 'white light' source. The light is passed through interferometer arms before and after a communication link. The light is modulated in a transmitter signal optical angle modulator and in a reference optical angle modulator. By locating an interferometer and light source at a receiver, the light passes through the interferometer both before and after the optical link to the transmitter. A balanced detector implements subtraction of non-interfering light.

Growing community of inventors

Belmont, MA, United States of America

Sumanth Kaushik