Abstract: This application describes, among others, wafer designs, testing systems and techniques for wafer-level optical testing by coupling probe light from top of the wafer.

Abstract: Various configurations of elongate scattering elements in an optical waveguide grating coupler for coupling light between a planar waveguide and an optical element such as an optical fiber, where the light may have a Gaussian intensity distribution. The elongate scattering elements are preferably curved, and in some embodiments, the scattering elements have elliptically curved shape. One or more of the elongate scattering elements may be segmented into various geometrical shapes, such as rectangular, square, circular and elliptical. The elongate scattering elements have at least one characteristic selected from the group consisting of grating width, height, spacing, depth and index of refraction forming the elongate scattering elements, where the magnitude of the at least one characteristic varies irregularly with position along the guiding portion of the optical waveguide grating coupler.

Abstract: Various configurations of elongate scattering elements in an optical waveguide grating coupler for coupling light between a planar waveguide and an optical element such as an optical fiber, where the light may have a Gaussian intensity distribution. The elongate scattering elements are preferably curved, and in some embodiments, the scattering elements have elliptically curved shape. One or more of the elongate scattering elements may be segmented into various geometrical shapes, such as rectangular, square, circular and elliptical. The elongate scattering elements have at least one characteristic selected from the group consisting of grating width, height, spacing, depth and index of refraction forming the elongate scattering elements, where the magnitude of the at least one characteristic varies irregularly with position along the guiding portion of the optical waveguide grating coupler.

Abstract: Photonic interconnect reconfigurably couples integrated circuits such as microprocessor, memory or other logic components. Detector, modulator, broad-band coupler and waveguide elements provide transmit and receive capability on CMOS substrate. Computer-implemented design software and reusable component library automate photonic and circuit design and simulation for manufacturability.

Abstract: High speed optical modulators can be made of a lateral PN diode formed in a silicon optical rib waveguide, disposed on a SOI or other silicon based substrate. A PN junction is formed at the boundary of the P and N doped regions. The depletion region at the PN junction overlaps with the center of a guided optical mode propagating through the waveguide. Electrically modulating a lateral PN diode causes a phase shift in an optical wave propagating through the waveguide. Each of the doped regions can have a stepped or gradient doping profile within it or several doped sections with different doping concentrations. Forming the doped regions of a PN diode modulator with stepped or gradient doping profiles can optimize the trade off between the series resistance of the PN diode and the optical loss in the center of the waveguide due to the presence of dopants.

Abstract: In a standard CMOS process, a layer of metallic salicide can be deposited on those selected portions of an integrated circuit, where it is desired to have metallic contacts for electronic components, such as transistors. The deposition of a salicide into optical elements such as the core of an optical waveguide or a light scatterer will damage the elements and prevent the passage of light through those sections of the elements. Prior to the deposition of the salicide, a salicide blocking layer is deposited on those parts of an integrated circuit, such as on an optical waveguide or a light scatterer, which are to be protected from damage by the deposition of salicide. The salicide blocking layer is used as one layer of the cladding of a silicon waveguide and a light scatterer.

Abstract: Photonic interconnect reconfigurably couples integrated circuits such as microprocessor, memory or other logic components. Detector, modulator, broad-band coupler and waveguide elements provide transmit and receive capability on CMOS substrate. Computer-implemented design software and reusable component library automate photonic and circuit design and simulation for manufacturability.

Abstract: An optical waveguide grating coupler for coupling light between a planar waveguide and an optical element such as an optical fiber. The optical waveguide grating coupler includes a grating comprising a plurality of elongate scattering elements. The optical waveguide grating coupler is preferably flared, and in various embodiments has hyperbolically shaped sidewalls. The elongate scattering elements are preferably curved, and in some embodiments, the scattering elements have elliptically curved shapes. Preferably, the elongated scattering elements have grating widths selected to accommodate the desired optical intensity distribution.

Abstract: An apparatus and method for splitting a received optical signal into its orthogonal polarizations and sending the two polarizations on separate dual integrated waveguides to other systems on chip for further signal processing. The present invention provides an apparatus and method for facilitating the processing of optical signals in planar waveguides received from optical fibers.

Abstract: This application describes, among others, wafer designs, testing systems and techniques for wafer-level optical testing by coupling probe light to/from the top of the wafer. A wafer level test system uses an optical probe to search for and align with an optical alignment loop. The test system uses a located alignment loop as a reference point to locate other devices on the wafer. The test system tests the operation of selected devices disposed on the wafer. The alignment loop is also used as a reference device for an adjacent device of unknown performance.

Abstract: A standard CMOS process is used to fabricate optical, optoelectronic and electronic devices at the same time on a monolithic integrated circuit. FIG. 12 shows an active waveguide formed by a standard CMOS process on a five layer substrate. The waveguide is a silicon strip loaded waveguide with a three layer core made of a silicon strip on a silicon slab with a silicon dioxide layer between the strip and slab. The active waveguide has two doped regions in the silicon slab adjacent to and on either side of the waveguide. FIG. 12A is a table summarizing the elements of the waveguide of FIG. 12 and the CMOS transistors of FIGS. 1 and 2, which are formed from the same materials at the same time on the same silicon substrate. In a standard CMOS process, a layer of metallic salicide can be deposited on those selected portions of an integrated circuit, where it is desired to have metallic contacts for electronic components, such as transistors.

Abstract: The index of refraction of waveguide structures can be varied by altering carrier concentration. The waveguides preferably comprise semiconductors like silicon that are substantially optically transmissive at certain wavelengths. Variation of the carrier density in these semiconductors may be effectuated by inducing an electric field within the semiconductor for example by apply a voltage to electrodes associated with the semiconductor. Variable control of the index of refraction may be used to implement a variety of functionalites including, but not limited to, tunable waveguide gratings and resonant cavities, switchable couplers, modulators, and optical switches.

Abstract: A group of waveguide grating couplers is disposed on a semiconductor substrate. The grating couplers are all within a spot illuminated on the substrate by a light from an optical fiber. The light propagating in the fiber is wavelength division multiplexed (WDM) and consists of several channels. Within the group of grating couplers, at least one grating coupler is designed to be tuned to each of the channels. The group of grating couplers demultiplexes the channels propagating in the fiber. A group of waveguide grating couplers can also be used to multiplex several channels of light into an optical fiber. Single mode and multimode fiber can be used to carry the multiplexed channels of light in an optical multiplexing and demultiplexing system.

Abstract: This application describes, among others, wafer designs, testing systems and techniques for wafer-level optical testing by coupling probe light to/from the top of the wafer. During the optical testing, the vertical spacing between an optical probe and the wafer is set to a very close distance, to achieve efficient optical coupling. It is beneficial to keep this close distance during optical testing as a constant in testing different optical components at different locations on the wafer. In one implementation, a spacing sensor may be used to measure the height of the optical probe from the wafer surface. This sensor may be a capacitance sensor that is mounted at the optical probe.

Abstract: An optical wavelength grating coupler incorporating one or more distributed Bragg reflectors (DBR) or other reflective elements to enhance the coupling efficiency thereof. The grating coupler has a grating comprising a plurality of scattering elements adapted to scatter light along a portion of an optical path, and the one or more DBRs are positioned with respect to the grating such that light passing through the grating towards the substrate of the grating coupler is reflected back by DBRs toward the grating. The DBR comprises a multilayer stack of various materials and may be formed on the substrate of the grating coupler. The grating coupler may include a gas-filled cavity, where the cavity is formed by a conventional etching process and is used to reflect light toward the grating. The grating coupler may also incorporate an anti-reflection coating to reduce reflective loss on the surface of the grating.

Abstract: This application describes, among others, wafer designs, testing systems and techniques for wafer-level optical testing by coupling probe light from top of the wafer.

Abstract: An optical wavelength grating coupler incorporating one or more distributed Bragg reflectors (DBR) or other reflective elements to enhance the coupling efficiency thereof. The grating coupler has a grating comprising a plurality of scattering elements adapted to scatter light along a portion of an optical path, and the one or more DBRs are positioned with respect to the grating such that light passing through the grating towards the substrate of the grating coupler is reflected back by DBRs toward the grating. The DBR comprises a multilayer stack of various materials and may be formed on the substrate of the grating coupler. The grating coupler may include a gas-filled cavity, where the cavity is formed by a conventional etching process and is used to reflect light toward the grating. The grating coupler may also incorporate an anti-reflection coating to reduce reflective loss on the surface of the grating.

Abstract: A fiber to chip coupling connecting an optical fiber to an integrated circuit. A section of fiber is laid on top of the surface of the chip, where the end of the fiber has been cut at an angle to form an angled tip. The angled tip has a flat surface which reflects light down to a waveguide grating coupler disposed on the integrated circuit. Light is reflected off the reflective surface of the angled tip by total internal reflection. The waveguide grating coupler is designed to accept the slightly diverging light beam from the reflective surface of the angled tip of the fiber. Light can also propagate through the fiber to chip coupler in the opposite direction, up from the substrate through the waveguide grating and into an optical fiber after bouncing off the reflective surface of the angled tip.

Abstract: Electronically controllable arrayed waveguide gratings (AWGs) with integrated phase error compensation for each individual arm of the array of waveguides. These AWGs and associated methods for static and dynamic phase compensation enable the fabrication of tunable AWGs which can track one or more drifting channels of an AWG.

Abstract: High speed optical modulators can be made of a lateral PN diode formed in a strip loaded optical waveguide on a SOI or other silicon based substrate. A PN junction is formed at the boundary of the P and N doped regions. The depletion region at the PN junction overlaps with the center of a guided optical mode propagating through the waveguide. Electrically modulating a lateral PN diode causes a phase shift in an optical wave propagating through the waveguide. Due to differences in fabrication methods, forming strip loaded waveguides with consistent properties for use in PN diode optical modulators is much easier than fabricating similar rib waveguides.