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Micro/Nano Scale

Latest Innovations
Quantum Nanopore Structure The invention provides a quantum well active region for an optoelectronic device. The quantum well active region includes barrier layers of high bandgap material.... Read More The invention provides a quantum well active region for an optoelectronic device. The quantum well active region includes barrier layers of high bandgap material. A quantum well of low bandgap material is between the barrier layers. Three-dimensional high bandgap barriers are in the quantum well. A preferred semiconductor laser of the invention includes a quantum well active region of the invention. Cladding layers are around the quantum well active region, as well as a waveguide structure.
Curved Coupled Waveguide Array A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide... Read More A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide guides emission. The waveguide includes a broad area straight coupling region that fans out into an array of narrower Individual curved coupled waveguides at an output facet of the laser. The individual curved coupled waveguides are curved according to Lorentzian functions that define the waveguide curvature as a function of position along the device. The integral length of each individual curved coupled waveguide differs from adjacent individual curved coupled waveguides by an odd number of half-wavelengths. The coupled waveguide array shapes the optical field output of the semiconductor laser such that a large fraction of the power is emitted into a small angular distribution using interference phenomena. A laser of the invention produces high power output with a very high quality, narrow beam shape.
Transistor Quantum Cascade Laser A method for producing light emission, including the following steps: providing a transistor structure that includes a semiconductor base region disposed between a... Read More A method for producing light emission, including the following steps: providing a transistor structure that includes a semiconductor base region disposed between a semiconductor emitter region and a semiconductor collector region; providing a cascade region between the base region and the collector region, the cascade region having a plurality of sequences of quantum size regions, the quantum size regions of the sequences varying, in the direction toward the collector region, from a relatively higher energy state to a relatively lower energy state; providing emitter, base and collector electrodes respectively coupled with the emitter, base, and collector regions; and applying electrical signals with respect to the emitter, base, and collector electrodes to cause and control light emission from the cascade region.
Impurity-Induced Method for High-Power Single-Mode Laser Researchers from the University of Illinois have developed a method for vertical-cavity surface-emitting laser (VCSEL) to provide high-power output with good beam... Read More Researchers from the University of Illinois have developed a method for vertical-cavity surface-emitting laser (VCSEL) to provide high-power output with good beam quality. The method use Zn-diffusion to create disordering and filter out high order mode of the laser. As a result, VCSEL with larger aperture, which permits higher power, will still output single mode light with tight focus. This technology provides laser for energy-assisted magnetic recording, which could be used in next generation hard disk drive.
Microdischarge Photodetectors This invention allows for the production of a family of photodetectors that are sensitive in the ultraviolet, visible, and near-infrared regions of the spectrum.... Read More This invention allows for the production of a family of photodetectors that are sensitive in the ultraviolet, visible, and near-infrared regions of the spectrum. Despite previous knowledge of photo responses to low pressure gas discharges, this technology is the first to achieve these responses without using plasma as the photosensitive element. The plasma instead amplifies the number of photoelectrons produced by the cathode's avalanche effect. Furthermore, the electronic properties of the photocathode material determine the spectral response of the photodetector. These photocathodes can then be composed of different materials to optimize the photodetector for more specific responsiveness. Details As the spatial dimensions of microplasma devices have continued to decrease they have become attractive for an increasingly wide range of applications. The microdischarge devices this technology enables are sensitive detectors of visible, near-IR, and UV radiation and significantly extend the use of silicon devices. The wavelength range over which microdischarge detectors are photosensitive can be extended by simply changing the photocathode material Therefore, detectors have a significant advantage over their semiconductor counterparts because of the wavelength agility available with a single, rugged device structure. Furthermore, the crystalline quality of the semiconductor photocathode in the microplasma device is unlikely to be critical. Consequently, one has the option of micromachining the detector from silicon and overcoating the cathode with a film of the appropriate semiconductor (or other material). Since this detector is fabricated in silicon, large arrays of devices can be produced economically. To date, arrays as large as 250,000 (500 x 500) have been tested successfully. These photodetectors combined with other advances in microdischarge technology lead to a bright future for nearly any application involving light. Information about other devices and applications using UIUC Microdischarge technology is available on request. Benefits Amenable to mass production: This invention can be readily integrated with other electronic or optoelectronic devices. Inexpensive: Because this device does not depend on the existence of a p-n junction the crystalline quality of the semiconductor is not an issue. More sensitive: This invention provides a photodetector in the visible and UV that is considerably more sensitive than commercial Si photodiodes.
Atomic Lasers with Excimer (Exciplex)-Assisted Absorption The invention provides in one of the embodiments for either a continuous wave (cw) or pulsed alkali laser having an optical cavity resonant at a wavelength defined... Read More The invention provides in one of the embodiments for either a continuous wave (cw) or pulsed alkali laser having an optical cavity resonant at a wavelength defined by an atomic transition, a van der Waals complex within the optical cavity, the van der Waals complex is formed from an alkali vapor joined with a polarizable gas, and a pump laser for optically pumping the van der Waals complex outside of the Lorentzian spectral wings wherein the van der Waals complex is excited to form an exciplex that dissociates forming an excited alkali vapor, generating laser emission output at the wavelength of the lasing transition.
Hybrid Plasma-Semiconductor Transistors Plasma-based electronic devices assumed a significant role in communications and display systems in the first half of the 20th century. One example is the plasma... Read More Plasma-based electronic devices assumed a significant role in communications and display systems in the first half of the 20th century. One example is the plasma voltage regulator (such as the OA, OB, OC, and OD series of rare gas plasma voltage regulators and electronic switches, and the 866A mercury plasma high voltage tube) that was widely incorporated into RF transmitters. This invention demonstrates that portions of a semiconductor transistor can be replaced by plasma, yielding a new family of three terminals, hybrid plasma electronic devices having properties previously unavailable. Details This invention provides hybrid semiconductor-plasma transistors in which the plasma replaces at least one semiconductor portion of a conventional transistor. Preferred embodiments of the invention provide a plasma bipolar junction transistor (PBJT) in which a plasma serves as the collector for an npn BJT. As the plasma conducts current, light is emitted that can be modulated by imposing a time-varying voltage across (or current through) the emitter-base junction of the PBJT. In this and other devices of the invention, the plasma may either be micro-cavity plasma, offering reduced volume and enhanced electron densities relative to macro-scopic plasma, or a larger volume (conventional) low temperature plasma. Other preferred embodiments of the invention provide plasma MOSFET devices in which plasma controls the conductance of the channel in a MOSFET. Applications Ultra High Resolution Plasma Displays Next Generation Flexible Displays Biomedical and Environmental Sensors Micro-analytical Instruments having low power consumption 3D chips Other applications where traditional transistors are used Benefits These transistors have reduced volumes and are thinner thus the devices formed with these transistors will be smaller and can be used in newer potential applications. The plasma transistors have enhanced electron densities and the plasma modulation can be controlled with very low voltages for the first time and thus the devices will be faster and very energy efficient.
Four Level Laser Pumping Method Researchers at the University of Illinois have developed a new laser pumping method which provides efficient and continuous high power (>10W) lasers in the... Read More Researchers at the University of Illinois have developed a new laser pumping method which provides efficient and continuous high power (>10W) lasers in the visible, ultraviolet, and near-infrared regions in both gas and solid state systems. This method allows cooling of the laser medium while achieving over 100% quantum efficiency. Combined with frequency doubling this laser should yield more than 10 watts of violet (426 or 427 nm), a region of the spectrum in which no powerful sources exist.
Direct Nanoscale Patterning of Metals Using Polymer Electrolytes Electrochemical fabrication platforms for making structures, arrays of structures and functional devices having selected nanosized and/or microsized physical... Read More Electrochemical fabrication platforms for making structures, arrays of structures and functional devices having selected nanosized and/or microsized physical dimensions, shapes and spatial orientations. Methods, systems and system components use an electrochemical stamping tool such as solid state polymeric electrolytes for generating patterns of relief and/or recessed features exhibiting excellent reproducibility, pattern fidelity and resolution on surfaces of solid state ionic conductors and in metal. Electrochemical stamping tools are capable high throughput patterning of large substrate areas, are compatible with commercially attractive manufacturing pathways to access a range of functional systems and devices including nano- and micro-electromechanical systems, sensors, energy storage devices, metal masks for printing, interconnects, and integrated electronic circuits.
Light Emitting Transistor and Laser This invention is the world's first light emitting transistor. The HBLET extends the capabilities of light-emitting diodes and could make this transistor the... Read More This invention is the world's first light emitting transistor. The HBLET extends the capabilities of light-emitting diodes and could make this transistor the fundamental element in electronics and optoelectronics. Details In a bipolar device there are two kinds of injected carriers, negatively charged electrons and positively charged holes. Some of these carriers, for example, a transistor, recombine rapidly, supported by a base current essential for normal transistor function. In the past, this base current has been regarded as a waste current that generates unwanted heat. However, this technology shows the base current creates light that can be modulated at transistor speed. This recombination process is the same (but enhanced by carrier transport) as the one used in LEDs to produce visible, rather than infared, light. The transistor laser produces infared radiation in phase with its base current, so it can be modulated at a switching speed impossible to attain with an LED. The switching speed obtained is fast enought to operate in fiber optic networks, as well as other applications. These transistors are made with indium gallium phosphide and gallium arsenide, unlike traditional transistors which have been built from silicon and germanium. The recombination process in indium gallium phosphide and gallium arsenide materials create infared photons, the "light" in the light emitting transistor. This contributes to the device's ability to operate as both a laser and a transistor. The existence of a third port (the photon output) can interconnect optical and electric signals for display or communication purposes. Additionally, electrical and optical qualities are increased by the incorporation of quantum wells into the active region of the transistors. The transistor laser has a unique capability in signal processing and electronic-photonic integrated circuits. Applications Electronics Optoelectronics Displays Benefits Speed: These transistors produce infared light in phase with their base current, allowing it to attain a switching speed superior to light emitting diodes (LEDs). Controlled light emission: Light intensity can be controlled by varying the base current. Simultaneous control of optical and electrical outputs: The addition of a third port allows greater control. Utilizes base current: Once considered wasteful, the base current is used to create light.

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