Yale University

United States of America as Represented by the Administrator of Nasa

Robert David Koudelka

Jerry M Woodall

Eric Harmon

Glen F Steele

David B Salzman

S Douglas Holland

Denise M Romero

Thomas Boone

A data multiplexer that accommodates both industry standard CCSDS data packets and bits streams and standard IEEE 1394 data is described. The multiplexer provides a statistical allotment of bandwidth to the channels in turn, preferably four, but expandable in increments of four up to sixteen. A microcontroller determines bandwidth requested by the plurality of channels, as well as the bandwidth available, and meters out the available bandwidth on a statistical basis employing flow control to the input channels.

Downlink data multiplexer

Methods are disclosed for producing highly doped semiconductor materials. Using the invention, one can achieve doping densities that exceed traditional, established carrier saturation limits without deleterious side effects. Additionally, highly doped semiconductor materials are disclosed, as well as improved electronic and optoelectronic devices/components using said materials. The innovative materials and processes enabled by the invention yield significant performance improvements and/or cost reductions for a wide variety of semiconductor-based microelectronic and optoelectronic devices/systems. Materials are grown in an anion-rich environment, which, in the preferred embodiment, are produced by moderate substrate temperatures during growth in an oxygen-poor environment. The materials exhibit fewer non-radiative recombination centers at higher doping concentrations than prior art materials, and the highly doped state of matter can exhibit a minority carrier lifetime dominated by radiative recombination at higher doping levels and higher majority carrier concentrations than achieved in prior art materials. Important applications enabled by these novel materials include high performance electronic or optoelectronic devices, which can be smaller and faster, yet still capture or emit light efficiently, and high performance electronics, such as transistors, which can be smaller and faster, yet cooler.

Methods of hyperdoping semiconductor materials and hyperdoped semiconductor materials and devices

A PLL circuit uses a multiple frequency range PLL in order to phase lock input signals having a wide range of frequencies. The PLL includes a VCO capable of operating in multiple different frequency ranges and a divider bank independently configurable to divide the output of the VCO. A frequency detector detects a frequency of the input signal and a frequency selector selects an appropriate frequency range for the PLL. The frequency selector automatically switches the PLL to a different frequency range as needed in response to a change in the input signal frequency. Frequency range hysteresis is implemented to avoid operating the PLL near a frequency range boundary.

Wide bandwidth phase-locked loop circuit

A light emitting device providing a first part that includes a source of excess minority carriers including excess electron-hole pairs; a second part, coupled to the first part, that includes a minority carrier barrier; and a third part, coupled to the second part, that includes a region that exhibits a low radiative recombination efficiency and a short minority carrier lifetime. In response to a first stimulus minority carriers are constrained by the second part to remain in the first part, leading to an increase of minority carrier radiative recombination in the first part and an increase in light emission; while in response to a second stimulus the minority carriers are enabled to cross the minority carrier barrier of the second part to enter the third part, leading to a decrease of minority carrier radiative recombination in the first part and a decrease in light emission.

High modulation frequency light emitting device exhibiting spatial relocation of minority carriers to a non-radiative recombination region

A light emitting device is constructed so as to provide a first part that includes a source of excess minority carriers including excess electron-hole pairs; a second part, coupled to the first part, that includes a minority carrier barrier; and a third part, coupled to the second part, that includes a region that exhibits a low radiative recombination efficiency and a short minority carrier lifetime. In response to a first stimulus minority carriers are constrained by the second part to remain in the first part, leading to an increase of minority carrier radiative recombination in the first part and an increase in light emission; while in response to a second stimulus the minority carriers are enabled to cross the minority carrier barrier of the second part to enter the third part, leading to a decrease of minority carrier radiative recombination in the first part and a decrease in light emission. In certain embodiments the first stimulus includes an absence of an electrical signal applied between the second part and the third part, and the second stimulus comprises a presence of the electrical signal applied between the second part and the third part. In other embodiments the first stimulus includes a change in an electric field in the second part that is generated by optically induced electron-hole pairs in the second part, and the second stimulus includes an absence of the change in the electric field. In another embodiment the reverse is true. In certain embodiments the first or second stimulus can be the presence of modulating light incident on the second part and a resultant decrease in band bending. The first part can include, by example, a light emitting diode, a laser diode, a resonant cavity LED, or a vertical cavity surface emitting laser device. In another, all optical embodiment the first part includes a material that, in response to optical pumping, provides a photoluminescent emission. The second part can include a resonant tunneling structure or a potential barrier structure formed by compositional grading or impurity concentration grading. The third part can include a low temperature grown material and/or a Schottky barrier contact. It is shown that embodiments of this invention are capable of exhibiting optical gain, and an optical semiconductor light emitting device with optical gain (SLEDOG) is thus made possible.

Growing community of inventors

New Haven, CT, United States of America

Robert David Koudelka