Kotura Inc. | Date: 2013-05-08
The light sensor and waveguide are positioned on a base such that a light signal guided by the waveguide is received at the light sensor. The waveguide includes a taper configured such that a ratio of a width of the waveguide at a first location in the taper:the width of the waveguide at a second location in the taper is greater than 1.2:1 where a length of the taper between the first location and the second location is less than 60 m.
Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 150.00K | Year: 2009
This Small Business Innovation Research Phase I project advances the field of silicon photonics which is emerging as a new, low cost, low power interconnect technology in applications as diverse as Active Cables for High Performance Computing to 100 Gb/s Ethernet transceivers for network centers. Like any new technology, silicon photonics has significant challenges incorporating disparate functions. To date the performance and size of optical building blocks are compromised by the wafer selection and the fabrication process. Some building blocks, wavelength multiplexers, for example, are best designed with waveguides in the 3-4 microns range for low loss and easy coupling to the outside world. Other building blocks, modulators for example, require waveguides of a single micron to keep their size small. The objective of this project is to address this integration challenge and demonstrate full feasibility for monolithic integration of optical components requiring vastly different geometrical and dimensional needs for light management on the same silicon wafer. In particular, modulators and multiplexers will be integrated onto the same chip. The broader impact / commercial potential of this project can be similar to the revolution witnessed in the semiconductor industry in the past few decades. Here innovation has enabled the semiconductor industry to grow to more than $250B in yearly sales. This has fueled dozens more businesses in high technology, software, communications, entertainment and health industries creating millions of jobs and a huge portion of the wealth in the U.S. and around the world. Silicon photonics brings a new level of innovation to semiconductor industry by incorporating optics onto the chip itself. There are two key problems with electrical paths: they are power hungry; and, only one lane wide. By contrast, optical signals can be separated into colors or wavelengths with each wavelength carrying its own signal on a waveguide re-used by many other optical signals. Muliplexers (WDM) are used to separate and combine wavelengths; modulators are used to encode the signals. Geo-photonics will take silicon photonics to a new level. This technology platform will replace electrical interconnect with optical ones in the next generation of Ethernet computers, network centers, storage and video servers, terabit routers, and supercomputers. It will ensure U.S. leadership in this new category of semiconductors.
Feng D.,Kotura Inc. |
Qian W.,Kotura Inc. |
Liang H.,Kotura Inc. |
Luff B.J.,Kotura Inc. |
Asghari M.,Kotura Inc.
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2013
Low power, low-cost, and high-speed photonic links are required in data centers. After significant research and development work over the last few years, silicon photonics has become a promising candidate to provide this technology. The receiver is one of the critical components for a photonic link. In this paper, we report recent progress in receiver technology on the silicon-on-insulator platform, particularly regarding its application to links that utilize wavelength division multiplexing (WDM). First, we discuss the key building blocks for WDM receivers: echelle grating demultiplexers and high-speed Ge photodetectors. We then report on the demonstration of a Terabit/s WDM receiver chip through monolithic integration of 40 high-speed Ge photodiodes with a 40-channel dense wavelength division multiplexing echelle grating. The device demonstrates that silicon photonics is a key technology to enable low-power and low-cost data center applications. © 1995-2012 IEEE. Source
Kotura Inc. | Date: 2014-07-02
Forming an optical device includes growing an electro-absorption medium in a variety of different regions on a base of a device precursor. The regions include a component region and the regions are selected so as to achieve a particular chemical composition for the electro-absorption medium included in the component region. An optical component is formed on the device precursor such that the optical component includes at least a portion of the electro-absorption medium from the component region. Light signals are guided through the electro-absorption medium from the component region during operation of the component.
Dong P.,Kotura Inc. |
Liao S.,Kotura Inc. |
Liang H.,Kotura Inc. |
Shafiiha R.,Kotura Inc. |
And 5 more authors.
Optics Express | Year: 2010
We present a broadband 2x2 electro-optic silicon switch with an ultralow switching power and fast switching time based on a Mach-Zehnder interferometer (MZI). Forward-biased p-i-n junctions are employed to tune the phase of silicon waveguides in the MZI, to achieve a p-phase switching power of 0.6 mW with a drive voltage 0.83 V with a MZI arm length of 4 mm. The 10%-90% switching time is demonstrated to be 6 ns. Optical crosstalk levels lower than ?17 dB are obtained for an optical bandwidth of 60 nm. The free carrier induced silicon refractive index change is extracted from the experimental results for the concentration range from 1016 to 1017 cm-3. We find that at the concentration of 1016 cm-3, the index change is about twice that calculated by the commonly used index change equation. © 2010 Optical Society of America. Source