News

7 December 2009

 

Advanced Photonix awarded high-speed photodiode patents

Picometrix LLC of Ann Arbor, MI, USA, a subsidiary of Advanced Photonix Inc (which designs and makes silicon, InP- and GaAs-based photodetectors, subsystems, and terahertz instrumentation), has been awarded US patents 7,078,741 for enhanced-responsivity photodiodes and 7,468,503 for planar photodiodes.

The firm says that these technologies can be used either individually or in combination and are deployed in its high-speed optical receiver (HSOR) products for the 40Gb/s and emerging 100Gb/s telecom markets. They enable increased responsivity, higher optical power handling capacity, and can be used across both the C and L wavelength bands. Picometrix says that its receivers are incorporated into high-speed optical communications equipment deployed to support high-definition video, data and voice users worldwide.

The patented photodiodes are high-reliability structures that accept light in a surface-normal geometry, achieve responsivity up to 0.85 amps per watt at 40Gb/s, and can handle high optical input power. The firm says that this patented surface normal design does not require complicated semiconductor optics to illuminate the photodiode, such as the spot-size converters that are necessary for waveguide photodiodes. As a result, a product based on these photodiodes covers both the C and L wavelength bands, is indifferent to optical polarization states, and has better reliability than mesa waveguide photodiodes, it is claimed. Indifference to polarization changes in leading-edge optical communication systems is important in maintaining transmission integrity due to the constantly changing polarization state of the incoming light.

“Proprietary, patented technology like this helps us differentiate our products in the market,” says Robin (Rob) Risser, president & general manager of Picometrix and chief financial officer of Advanced Photonix. Since the photodiodes can be used for both C and L wavelength bands, customer material management can be simplified and their inventory requirements reduced, he claims. “In addition, indifference to polarization changes improves our product uniformity across operating conditions, which can contribute to improved customer manufacturing yield,” Risser adds. “Our high-reliability planar photodiode structure also offers our customers the comfort of long-term reliability they have become accustomed to with lower speed legacy systems.”

Advanced Photonix announces 40G telecom design win

In early November, Picometrix was selected to supply high-speed optical receivers to what it describes as a leading OEM telecom systems provider. The annual commitment is estimated to be more than $800,000, with volume shipments beginning in the firm's fiscal fourth-quarter 2010 (to end March). The new design win is for 40Gb/s ultra-long-haul communications in dense wavelength division multiplexing (DWDM) systems that use NRZ-DPSK (nonreturn-to-zero differential phase-shift keying) modulation.

The patented photodiodes and proprietary amplifiers used in the receivers are designed with dual inputs for balanced detection to support data rates up to 43Gb/s. The balanced receiver operates over the entire C and L wavelength bands with low polarization-dependent responsivity.

“This agreement with a major tier 1 telecom OEM is only one of several design wins with tier 1 and tier 2 OEMs that we have been working on this past year,” says Risser. “We anticipate additional design wins will move to volume production status during 2010, and look forward to a long and rewarding relationship with this key customer.”

See related items:

Picometrix inks agreement to supply 40G optical receivers

Advanced Photonix joins Georgia Tech 100G Optical Networking Consortium

Search: Picometrix InP GaAs Photodetectors Photodiodes

Visit: www.advancedphotonix.com