17 March 2020
NeoPhotonics unveils complete L-band coherent optics solution to double optical fiber capacity
NeoPhotonics Corp of San Jose, CA, USA (a vertically integrated designer and manufacturer of silicon photonics and hybrid photonic integrated circuit-based lasers, modules and subsystems for high-speed communications) has announced an L-band suite of coherent optical components, including its 64GBaud L-band high-bandwidth coherent driver modulator (HB-CDM), 64GBaud L-band intradyne coherent receiver (ICR) and ultra-narrow-linewidth L-band tunable laser micro-ITLA (integrated tunable laser assembly). Together with NeoPhotonics standard C-band coherent components, the new products enable customers to double the capacity of optical fiber links.
The C-band is the primary band for telecoms, with wavelengths centered around 1550nm. The L-band uses wavelengths centered around 1590nm and is primarily used to complement the C-band to increase data capacity, especially in long-haul networks. By adding channels in the L-band, operators can double the capacity of an optical fiber.
NeoPhotonics’ 64Gbaud coherent components and tunable lasers enable single-channel 600G data transmission over data-center interconnect (DCI) distances of about 80km using 64 QAM (quadrature amplitude modulation). These components also support 400G over metro distances of 400-600km using 64GBaud and 16 QAM or 200G over long-haul distances of greater than 1000km using 64GBaud and QPSK (quad phase-shift keying).
NeoPhotonics’ L-band external cavity laser (ECL) micro-ITLA incorporates the same laser architecture as the firm’s C-band laser for a pure optical signal with an ultra-narrow linewidth and very low phase noise. In coherent systems, any error in the phase of the signal and reference lasers, due to the laser’s linewidth, can cause data errors, making narrow linewidth critical in systems using higher-order modulation.
NeoPhotonics’ 64 Gbaud L-band HB-CDM co-packages an indium phosphide (InP)-based Mach-Zehnder (MZ) quadrature modulator chip with a linear, quad-channel, differential 64GBaud driver. Both the C-band and L-band versions of the HB-CDM are designed to be compliant with the Optical Internetworking Forum (OIF) Implementation Agreement OIF-HB-CDM-01.0 ‘High Bandwidth Coherent Driver Modulator’.
NeoPhotonics’ 64Gbaud L-band micro-ICR incorporates an integrated co-mixer chip and four balanced photodiodes with four differential linear amplifiers to provide four output channels at 64GBaud. The form factor of the high-bandwidth coherent receiver is designed to be compliant with the OIF Implementation Agreement for Micro Integrated Intradyne Coherent Receivers; IA # OIF-DPC-MRX-02.0.
For applications that require more capacity than provided by the standard C-band but do not require the full L-band, each of these components is available in a C++ version, which supports tuning across the full Super C-band covering 6.0THz of spectrum or up to 50% more than standard systems. These C++ components can support 80 channels at 75GHz channel spacing, which effectively increases the capacity of an optical fiber by as much as 50% over standard C-band-only systems at comparable distances.
“We are pleased to add L-band versions to our existing suite of coherent components, thus providing customers with a complete solution to their fiber capacity requirements, whether C-band, C++ band or L-band,” says chairman & CEO Tim Jenks. “Our ultra-pure tunable laser design and our high-performance coherent modulator and receiver designs are very flexible and excel in different spectral regimes to provide the highest speed over distance performance,” he concludes.