Abstract:
An arrangement for improving adhesive attachment of micro-components in an assembly utilizes a plurality of parallel-disposed slots formed in the top surface of the substrate used to support the micro-components. The slots are used to control the flow and “shape” of an adhesive “dot” so as to quickly and accurately attach a micro-component to the surface of a substrate. The slots are formed (preferably, etched) in the surface of the substrate in a manner that lends itself to reproducible accuracy from one substrate to another. Other slots (“channels”) may be formed in conjunction with the bonding slots so that extraneous adhesive material will flow into these channels and not spread into unwanted areas.
Abstract:
A planar, waveguide-based silicon Schottky barrier photodetector includes a third terminal in the form of a field plate to improve the responsivity of the detector. Preferably, a silicide used for the detection region is formed during a processing step where other silicide contact regions are being formed. The field plate is preferably formed as part of the first or second layer of CMOS metallization and is controlled by an applied voltage to modify the electric field in the vicinity of the detector's silicide layer. By modifying the electric field, the responsivity of the device is “tuned” so as to adjust the momentum of “hot” carriers (electrons or holes, depending on the conductivity of the silicon) with respect to the Schottky barrier of the device. The applied potential functions to align with the direction of momentum of the “hot” carriers in the preferred direction “normal” to the silicon-silicide interface, allowing for an increased number to move over the Schottky barrier and add to the generated photocurrent.
Abstract:
An optical interconnection arrangement for use in high data applications is presented that eliminates the need for extensive serialization/de-serialization (SERDES) functionality by utilizing pulse amplitude modulation (PAM) techniques to represent the data in the optical domain while utilizing a separate channel for transmitting an optical clock signal, eliminating the need for clock recovery circuitry on the receive end of the arrangement.
Abstract:
A high speed silicon-based optical modulator with control of the dopant profiles in the body and gate regions of the device reduces the series resistance of the structure without incurring substantial optical power loss. That is, the use of increased dopant values in areas beyond the active region will allow for the series resistance to be reduced (and thus increase the modulating speed of the device) without incurring too large a penalty in signal loss. The dopant profiles within the gate and body regions are tailored to exhibit an intermediate value between the high dopant concentration in the contact areas and the low dopant concentration in the carrier integration window area.
Abstract:
An HDMI interconnect arrangement is presented that performs a pulse-amplitude modulation (PAM) conversion of the TMDS audio/video signals in order to simultaneously transmit all three channels over a single optical fiber. The set of three audio/video TMDS channels is applied as an input to a PAM-8 optical modulator, which functions to encode the set of three channels onto an optically-modulated output signal. The modulated optical signal is thereafter coupled into an optical fiber within an active HDMI cable and transmitted to an HDMI receiver (sink). The TMDS CLK signal is not included in this conversion into the optical domain, but remains as a separate electrical signal to be transmitted along a copper signal path within the active HDMI cable.
Abstract:
A silicon-based optical modulator is configured as a multi-segment device that utilizes a modified electrical data input signal format to address phase modulation nonlinearity and attenuation problems associated with free-carrier dispersion-based modulation. The modulator is formed to include M separate segments and a digital signal encoder is utilized to convert an N bit input data signal into a plurality of M drive signals for the M modulator segments, where M≧2N/2. The lengths of the modulator segments may also be adjusted to address the nonlinearity and attenuation problems. Additional phase adjustments may be utilized at the output of the modulator (beyond the combining waveguide).
Abstract:
A wafer scale implementation of an opto-electronic transceiver assembly process utilizes a silicon wafer as an optical reference plane and platform upon which all necessary optical and electronic components are simultaneously assembled for a plurality of separate transceiver modules. In particular, a silicon wafer is utilized as a “platform” (interposer) upon which all of the components for a multiple number of transceiver modules are mounted or integrated, with the top surface of the silicon interposer used as a reference plane for defining the optical signal path between separate optical components. Indeed, by using a single silicon wafer as the platform for a large number of separate transceiver modules, one is able to use a wafer scale assembly process, as well as optical alignment and testing of these modules.
Abstract:
A silicon-based optical modulator is configured as a multi-segment device that utilizes a modified electrical data input signal format to address phase modulation nonlinearity and attenuation problems associated with free-carrier dispersion-based modulation. The modulator is formed to include M separate segments and a digital signal encoder is utilized to convert an N bit input data signal into a plurality of M drive signals for the M modulator segments, where M≧2N/2. The lengths of the modulator segments may also be adjusted to address the nonlinearity and attenuation problems. Additional phase adjustments may be utilized at the output of the modulator (beyond the combining waveguide).
Abstract:
A silicon-on-insulator (SOI)-based tunable laser is formed to include the gain medium (such as a semiconductor optical amplifier) disposed within a cavity formed within the SOI substrate. A tunable wavelength reflecting element and associated phase matching element are formed on the surface of the SOI structure, with optical waveguides formed in the surface SOI layer providing the communication between these components. The tunable wavelength element is controlled to adjust the optical wavelength. Separate discrete lensing elements may be disposed in the cavity with the gain medium, providing efficient coupling of the optical signal into the SOI waveguides. Alternatively, the gain medium itself may be formed to include spot converting tapers on its endfaces, the tapers used to provide mode matching into the associated optical waveguides.
Abstract:
A silicon-based optical modulator structure includes one or more separate localized heating elements for changing the refractive index of an associated portion of the structure and thereby providing corrective adjustments to address unwanted variations in device performance. Heating is provided by thermo-optic devices such as, for example, silicon-based resistors, silicide resistors, forward-biased PN junctions, and the like, where any of these structures may easily be incorporated with a silicon-based optical modulator. The application of a DC voltage to any of these structures will generate heat, which then transfers into the waveguiding area. The increase in local temperature of the waveguiding area will, in turn, increase the refractive index of the waveguiding in the area. Control of the applied DC voltage results in controlling the refractive index