In booth 1601 at the Optical Fiber Communication (OFC) exhibition in Anaheim (19-21 March), NeoPhotonics Corp of San Jose, CA, a vertically integrated designer and manufacturer of both indium phosphide (InP) and silica-on-silicon photonic integrated circuit (PIC)-based modules and subsystems, has launched a 100G variable-power intradyne coherent receiver (VICR).
The PIC-based VICR integrates a variable optical attenuator (VOA) on the signal path and is designed to increase dynamic range and improve the optical signal-to-noise ratio (OSNR) for both single channel and multiple coincident signals. This capability is designed to enable service providers to better manage network capacity in colorless coherent networks. NeoPhotonics is sampling the VICR and expects it to enter general availability in second-half 2013.
Core networks are rapidly moving towards more efficient ‘colorless’ operation, so reconfigurable optical add-drop multiplexer (ROADM) add and drop ports are not limited to fixed pre-determined wavelength channels. Instead, a tunable transmitter can connect any wavelength to any add port and the ROADM can route any wavelength to any drop port receiver. Colorless operation improves the efficiency of valuable line-cards and transponders in coherent transport networks, where a single DWDM channel carries 100Gbps of information.
In coherent optical communications systems the colorless channel drop operation is enabled by using the local oscillator laser and the VICR to select the receive channel, eliminating the need for a terminal optical filter. The VICR then detects the signal channel to which the local oscillator laser is matched, but all other channels are outside the device bandwidth. In colorless applications the remaining channels are not filtered out optically, so the incoming signal power to the VICR can vary significantly depending on how many other channels are present, resulting in up to 100 times higher power falling on the receiver than in the single channel case. NeoPhotonics’ VICR integrates a PIC variable optical attenuator that provides control and stability to the input signal. In both colorless and conventional optically filtered systems, the VOA also improves performance by allowing system selection of the optimal operating point to enhance OSNR and reduce the effects of optical impairments such as polarization dependent loss (PDL).
“The VICR illustrates the power of photonic integration to provide additional functionality to our existing products, which are designed to benefit our customers with improved performance in the same form factor and simplified board layouts,” says chairman & CEO Tim Jenks.
At OFC, NeoPhotonics is showcasing the VICR alongside its existing product portfolio, including other intradyne coherent receivers and narrow-linewidth tunable lasers for 100G coherent communications, its 100G CFP and CFP2 transponders for client-side transmission and an extensive line of OLT transceivers for FTTH PON networks.
In addition, NeoPhotonics’ personnel are participating in a workshop and a panel devoted to passive optical network (PON) access applications and presenting a paper on ROADM-based wavelength agility:
Dr David Piehler, chief scientist, Access Products, is discussing the topic ‘Statistical WDM is antifragile’ in Workshop OM1D ‘Can Access Networks Afford to be Wavelength Agile?’ (Monday 18 March, 9am-12pm, in Room 303D), which examines architectural and cost considerations in the coming multi-wavelength PON systems and optical distribution networks (ODN). Piehler is also giving a presentation on ‘Scaling PON OLT port utilization – HFC style’ (Monday 18 March, 4-6pm, Room: 304C) in connection with Panel NM3J ‘PONs as Used by MSOs’, which considers the role of PON architectures for commercial and residential services in MSO networks and the timing of PONs in the residential sector. chief systems architect Dr Winston Way and two co-authors from NEC Laboratories America are presenting the paper ‘Contention resolution within colorless and directionless ROADM’ (Wednesday 20 March, 8am, Room 304C).
