MONTEREY PARK, Calif.–(Business Wire)–
Kotura, Inc., a leading provider of Silicon Photonics products, today announced
that it has demonstrated a high-speed horizontal p-i-n germanium photo detector
integrated with silicon waveguides on a single chip.

“The previous research has focused on vertical detectors within sub-micron scale
waveguides to achieve high speed operation. These typically exhibit high loss
and are hard to integrate with waveguide geometries needed for other
functionalities such as WDM (wavelength division multiplexing) multiplexer and
de-multiplexer devices,” reported Mehdi Asghari, Chief Technical Officer of
Kotura. “Our invention of a horizontal junction detector does away with
conventional designs and creates a new structure that supports high speed
operation and yet is compatible with a variety of waveguide heights including
the larger waveguides needed for high performance WDM operation. These
structures allow standard silicon processing techniques to be used to couple
waveguides and photo-detectors on the same chip with extremely low loss and high
performance. We have demonstrated devices with more than 32 GHz optical
bandwidth @1V bias, a responsivity of 1.1 A/W, a dark current <300nA and a fiber
coupling loss of less than 1.2dB.”

“A low-loss, high-speed, easy-to-manufacture detector is a key component for
optical interconnects. When we evaluated these devices we were impressed by
their performance,” commented Dr. Ashok Krishnamoorthy, Principal Investigator
on this project at Sun Labs, Oracle America, Inc. “This horizontal junction
detector is a huge improvement for several reasons, not the least among which is
that it can be readily coupled to single-mode fiber. This opens the door for
wavelength-multiplexed silicon-based optical interconnects that will reduce the
complexity of connectors and cabling in high-performance systems.”

“Now we can easily integrate WDM and detection functionality into one chip,”
added Mehdi Asghari, CTO of Kotura. “A single silicon photonics device that can
take a single input stream of light with 100 WDM channels, demultiplex the
wavelengths and route each wavelength to its own detector. We can envision
integrating 100 receiver channels, each operating at 40 Gb/s, on a single chip.”

The Kotura`s horizontal detector was developed as part of the Defense Advanced
Research Project Agency`s Ultra-performance Nano-photonic Intrachip
Communications (UNIC) program in conjunction with Oracle America, Inc., under
the leadership of Dr. Jagdeep Shah, DARPA Program Manager. An article,
“High-speed Ge photo-detector monolithically integrated with large cross-section
silicon-on-insulator waveguide,” by Dazeng Feng et al. was recently published in
Applied Physics Letters.

About Kotura, Inc.

Kotura, Inc., a worldwide leader in Silicon Photonics, designs, manufactures and
markets a portfolio of application-specific silicon photonics products for the
communications, computing, sensing, and detection markets. An ISO 9001:2000
certified company, Kotura has been in mass production of silicon photonics
components for more than four years. Kotura is an active participant in the IEEE
802.3ba 40 Gb/s and 100 Gb/s Ethernet Standards Committee, the Video Electronics
Standards Association (VESA) and the Silicon Photonics Alliance, the first
formal Community of Interest with the Optoelectronics Industry Development
Association (OIDA).

Kotura, Inc.
Arlon Martin
Phone: 626-236-4500
Fax: 626-236-4501
E-mail: amartin@kotura.com

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