摘要:
An optical structure that reduces the effects of spontaneous emissions from the active region of a laser. An optical structure includes optimizations to reduce the effects of spontaneous emissions. The optical structure includes a VCSEL with top and bottom DBR mirrors and an active region connected to the mirrors. The optical structure further includes a photodiode connected to the VCSEL. One or more optimizations may be included in the optical structure including optically absorbing materials, varying the geometry of the structure to change reflective angles, using optical apertures, changing the reflectivity of one or more mirrors, changing the photodiode to be more impervious to spontaneous emissions, and using ion implants to reduce photoluminescence efficiency.
摘要:
The present invention provides a method for detecting bacteria and a nano-well device having one or more input/output connections about a gap and one or more bacteriophages at or about the gap that trigger a detectable electrical field fluctuation when the one or more bacteriophages contact a cognate target within a liquid sample.
摘要:
A VCSEL having an N-type Bragg mirror with alternating layers of high bandgap (low index) and low bandgap (high index) layers of AlGaAs. The layers may be separated by a step change of Al composition followed by a graded region, and vice versa for the next layer, in the N-type mirror to result in a lower and more linear series resistance. Also, an N-type spacer layer may be adjacent to an active region of quantum wells. There may be a similar step in a change of Al composition from the nearest layer of the N-type mirror to the N-type spacer formed from a lower bandgap direct AlGaAs layer to provide lower free carrier absorption. With electron affinity engineering, a minority carrier hole barrier may be inserted adjacent to the quantum wells to improve hole confinement at high current density and high temperature.
摘要:
A temperature compensation system for semiconductor logic gates where the temperature compensation is accomplished by two depletion mode FET's in electrical series relationship is disclosed. One of the FET's is adapted to operate in its triode region of operation and the other in its saturation region of operation.
摘要:
A differential stage of an amplifier includes an input transistor and a second transistor with a significantly greater emitter cross-sectional area than the input transistor. Quiescent emitter current is divided between the two transistors in substantially the same ratio as the emitter cross-sectional areas so that the emitter current densities are substantially equal.
摘要:
A method of determining antimicrobial activity of an agent can include providing a well, wherein the well contains at least one antimicrobial agent, the well further including at least two electrodes. A sample of a microbe can be added into the well and a voltage pulsed between the electrodes. An electrical property can be sampled and recorded. In another aspect, a method of identifying at least one microbe includes taking a sample containing the at least one microbe, isolating the at least one microbe from the sample, dividing the at least one microbe into a at least one well, wherein each well contains at least one antimicrobial agent and at least two electrodes. A voltage is pulsed between the at least two electrodes, an electrical property is sampled during the pulsing and recorded. In another aspect, a diagnostic device for detecting at least one microbe is presented.
摘要:
Disclosed are methods for providing wafer photonic flow control to a semiconductor wafer (1700) having a substrate (1720), at least one active layer (1765) and at least one surface layer (1710). Photonic flow control can be achieved through the formation of trenches (1725) and/or insulating implants (1730) formed in said wafer (1700), whereby active regions (1760) are defined by trenches (1725) that operate as nonconductive areas (1750). Methods of and systems for wafer level burn-in (WLBI) of semiconductor devices are also disclosed. Photonic flow control at the wafer level is important when using WLBI methods and systems.
摘要:
An optical structure that reduces the effects of spontaneous emissions from the active region of a laser. An optical structure includes optimizations to reduce the effects of spontaneous emissions. The optical structure includes a VCSEL with top and bottom DBR mirrors and an active region connected to the mirrors. The optical structure further includes a photodiode connected to the VCSEL. One or more optimizations may be included in the optical structure including optically absorbing materials, varying the geometry of the structure to change reflective angles, using optical apertures, changing the reflectivity of one or more mirrors, changing the photodiode to be more impervious to spontaneous emissions, and using ion implants to reduce photoluminescence efficiency.
摘要:
A method and apparatus for fabricating a metamorphic long-wavelength, high-speed photodiode, wherein a buffer layer matching a substrate lattice constant is formed at normal growth temperatures and a thin grading region which grades past the desired lattice constant is configured at a low temperature. A reverse grade back is performed to match a desired lattice constant. Thereafter, a thick layer is formed thereon, based on the desired lattice constant. Annealing can then occur to isolate dislocated material in a grading layer and a reverse grading layer. Thereon a strained layer superlattice substrate is created upon which a high-speed photodiode can be formed. Implant or diffusion layers grown in dopants can be formed based on materials, such as Be, Mg, C, Te, Si, Se, Zn, or others. A metal layer can be formed over a cap above a P+ region situated directly over an N-active region. The active region also includes a p-doped region. The high-speed photodiode can thus be formed utilizing GaAs, or other substrate material, such as germanium and silicon.
摘要:
A turbidity sensor is provided with two light sensitive components or elements. One light sensitive component is displaced from a light source, such as a light emitting diode, so that a fluid can pass therebetween. A second light sensitive component is disposed within a common compartment with the light source so that it can measure the intensity of light provided by the light source. The light source and the second light sensitive components can be individual elements, or chips, within a common component package. A regulator is provided to control the magnitude of current provided to the light source so that its light intensity can be regulated. In this manner, the intensity of light emitted by the light source, such as a light emitting diode, can be controlled regardless of the aging of the LED, the variability of LED characteristics and the temperature surrounding the LED. The constant light emission from the light source permits the other light sensitive component to be used as a reliable indication of the turbidity of a solution passing between the light source and the first light sensitive component.