Massachusetts Institute of Technology

Other

Leonard M Johnson

Rabindra N Das

Mark A Gouker

Pascale Gouker

Ryan C Johnson

Charles H Cox

Gary E Betts

Alexander Sonnenschein

Warren K Hutchinson

A multi-layer semiconductor device includes two or more semiconductor sections, each of the semiconductor sections including at least at least one device layer having first and second opposing surfaces and a plurality of electrical connections extending between the first and second surfaces. The electrical connections correspond to first conductive structures. The multi-layer semiconductor device also includes one or more second conductive structures which are provided as through oxide via (TOV) or through insulator via (TIV) structures. The multi-layer semiconductor device additionally includes one or more silicon layers. At least a first one of the silicon layers includes at least one third conductive structure which is provided as a through silicon via (TSV) structure. The multi-layer semiconductor device further includes one or more via joining layers including at least one fourth conductive structure. A corresponding method for fabricating a multi-layer semiconductor device is also provided.

Multi-layer semiconductor devices fabricated using a combination of substrate and via structures and fabrication techniques

A multi-layer semiconductor device includes a first semiconductor structure having first and second opposing surfaces, the second surface of the first semiconductor structure having at least a first semiconductor package pitch. The multi-layer semiconductor device also includes a second semiconductor structure having first and second opposing surfaces, the first surface of the second semiconductor structure having a second semiconductor package pitch. The multi-layer semiconductor device additionally includes a third semiconductor structure having first and second opposing surfaces, the first surface of the third semiconductor structure having a third semiconductor package pitch which is different from at least the second semiconductor package pitch. The second and third semiconductor structures are provided on a same package level of the multi-layer semiconductor device. A corresponding method for fabricating a multi-layer semiconductor device is also provided.

Interconnect structures for assembly of multi-layer semiconductor devices

An optical link exhibiting net gain without the use of optical or electronic amplifiers. The link includes a high-power laser, a high-sensitivity external modulator for intensity modulating the laser output, an optical fiber, and photodiode detector. The electrical input port of the external modulator is impedance-matched to the output port of an electrical signal source using a transformer double-tuned circuit. The link exhibits electrical transfer efficiency (i.e., gain) proportional to the square of the optical bias power and modulator sensitivity, and much lower insertion loss than prior art links. The link can be advantageously used wherever low-insertion loss, high bandwidth, and low distortion transmission of electrical signals is required over distances up to ten kilometers.

Optical link

An electro-optic system for mixing and/or transmitting electrical signals using an optical carrier is described in which the electrical signals are applied to an electro-optic intensity modulator with a nonlinear transfer function, preferably of the Mach-Zehnder interferometric type biased at the transmission null point. The modulator output optical signal is transmitted to a receiver where it is detected and voltage products of the applied electrical signals are recovered.

Electro-optic system

An electro-optical modulating system has a light source for producing a carrier wave. The carrier wave is polarized by a polarizer so as to adjust the power of the carrier wave in transverse electric (TE) polarization mode and in transverse magnetic (TM) polarization mode. In addition to a polarizer the electro optical modulating includes at least one set of electrodes for adjusting phase biases of the TE and TM polarization mode components of the carrier wave. The electrodes allow independent control of the phase biases of the respective TE polarization mode components and TM polarization mode components. Multiple sets of electrodes for adjusting the phase biases may be used. A modulating means is also included for modulating the carrier wave so as to encode information. The modulating system preferably also includes an interferometric modulator comprised of at least two branches. The modulation and phase bias adjustment take place on both of the respect branches.

Reduction of modulator non-linearities with independent bias angle

Non-linear distortion of a modulated light carrier wave arising from optical modulator nonlinearity of significantly reduced by offsetting a dominant cubic term of intermodulation distortion in transverse electric (TE) mode with a dominant cubic term of intermodulation distortion in transverse magnetic (TM) mode. The offset is achieved by adjusting the magnitude of the components of light in TE mode and TM mode to compensate for the differing response of components of the light wave in TM mode versus components in TE mode to a given voltage level applied to the carrier wave during modulation. The adjustments to the relative magnitude can be performed by a polarizer or polarization-preserving fiber. This method may be used in a modulating system and an electro-optical communication system.

Apparatus and method for reducing modulator nonlinearities

An integrated optical transducer includes a single mode input optical waveguide, two single mode optical waveguide branches having different physical lengths, and a single mode output optical waveguide. When used as a transducer, the optical path lengths of the waveguide branches are dependent on the physical quantity measured. A plurality of such transducer elements may be used jointly to provide a binary output of high sensitivity and wide range of measurement. The waveguide element may also be used as an optical pulse source.

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Carlisle, MA, United States of America

Leonard M Johnson