Showing papers by "Finisar published in 2014"

Sub-banded / single-sub-carrier drop-demux and flexible spectral shaping with a fine resolution photonic processor

Abstract: Spectral processor based on arrayed waveguide grating and free-space manipulation is capable of arbitrary filtering at record metrics of 0.8GHz resolution over 200GHz span. Narrowband coherent drop-demultiplexing and controlled optical shaping is demonstrated in unison with digital sub-banding.

Hybrid silicon photonic circuits and transceiver for 56Gb/s NRZ 2.2km transmission over single mode fiber

Abstract: Using hybrid integration of electronics and silicon photonics integrated circuits, we demonstrate the generation and detection of up to 56Gb/s NRZ optical signals over 2km standard single mode fiber at 1310nm wavelength. The link operates error free at 40Gb/s and under KR4 FEC threshold at 56Gb/s.

Evolution of VCSELs

Abstract: Over the last 20 years, nearly 1 billion VCSELs have been shipped, the vast majority of them emitting at 850nm using GaAs active regions, and primarily used in data communications and optical tracking applications. Looking to the future, the ever increasing speed of data communications is driving the VCSEL to evolve with more complex active regions, optical mode control, and alternate wavelengths to meet the more stringent requirements. We will discuss the current state of VCSELs for 28Gbps, and higher speeds, focusing on evolution to more complex active regions and alternate wavelength approaches, particularly as the market evolves to more active optical cables. Other high volume applications for VCSELs are driving improvements in single mode and optical power characteristics. We will present several evolving market trends and applications, and the specific VCSEL requirements that are imposed. The ubiquitous 850nm, GaAs active region VCSEL is evolving in multiple ways, and will continue to be a viable optical source well in to the future.

Latch mechanism for communication module

Abstract: Latch mechanism for communication modules. In an example embodiment, a module latch mechanism includes a follower configured to be slidingly positioned relative to a housing and a driver configured to be rotatingly positioned relative to the housing. The follower includes a first arm configured to facilitate selective engagement of the housing with a host device. The follower may further include a fastening mechanism configured to facilitate selective engagement of the follower with the housing. The driver is configured to be positioned relative to the follower such that the driver urges the follower toward a first position relative to the housing as the driver is rotated from an unlatched position to a latched position.

Reliability of VCSELs for >25Gb/s

Abstract: The next individual-channel VCSEL (Vertical Cavity Surface Emitting Laser) node for data communications is 25 Gbps or higher. Providing the required reliability becomes ever more challenging as the speeds increase, but possible with proper design.

High Reflectivity LCOS Device

Abstract: Described herein is a spatial light modulator (15) for modulating the phase, retardation or polarization state of an incident optical signal propagating in a first dimension. The optical phase modulator (15) includes a liquid crystal material (17) and a pair of electrodes (19 and 21) for supplying an electric potential across the liquid crystal material (17) to drive liquid crystals in a predetermined configuration. Modulator (15) also includes a diffractive optical element (29) disposed adjacent a first electrode (19). Element (29) includes a first array of diffractive elements (31) formed of a first material having a first refractive index and extending in a second dimension substantially perpendicular to the first dimension. Elements (31) are at least partially surrounded by a second material (33) formed of a lower refractive index.

Demonstration of fully enabled data center subsystem with embedded optical interconnect

Abstract: The evolution of data storage communication protocols and corresponding in-system bandwidth densities is set to impose prohibitive cost and performance constraints on future data storage system designs, fuelling proposals for hybrid electronic and optical architectures in data centers. The migration of optical interconnect into the system enclosure itself can substantially mitigate the communications bottlenecks resulting from both the increase in data rate and internal interconnect link lengths. In order to assess the viability of embedding optical links within prevailing data storage architectures, we present the design and assembly of a fully operational data storage array platform, in which all internal high speed links have been implemented optically. This required the deployment of mid-board optical transceivers, an electro-optical midplane and proprietary pluggable optical connectors for storage devices. We present the design of a high density optical layout to accommodate the midplane interconnect requirements of a data storage enclosure with support for 24 Small Form Factor (SFF) solid state or rotating disk drives and the design of a proprietary optical connector and interface cards, enabling standard drives to be plugged into an electro-optical midplane. Crucially, we have also modified the platform to accommodate longer optical interconnect lengths up to 50 meters in order to investigate future datacenter architectures based on disaggregation of modular subsystems. The optically enabled data storage system has been fully validated for both 6 Gb/s and 12 Gb/s SAS data traffic conveyed along internal optical links.

Digital QAM Modulation and Equalization for High Performance 400 GbE Data Center Modules

Abstract: A digital QAM modem concept is proposed and investigated for 400-Gb/s data center modules based on 25G DFB transmitter technology. Monte-Carlo simulations, including DFB nonlinearities and RIN, show 2-dB advantage for QAM over optimized DMT.

56 Gb/s transmission over 100m OM3 using 25G-class VCSEL and discrete multi-tone modulation

Abstract: We report experimental data demonstrating 56 Gb/s VCSEL transmission over 100m OM3, and 40 Gb/s transmission over 200m OM3 using discrete multi-tone modulation. This result is achieved with a conventional 850nm 25G-class VCSEL.

Electronic dispersion compensation in a 50 Gb/s optically unamplified direct-detection receiver enabled by vestigial-sideband orthogonal frequency division multiplexing

Abstract: We present a novel method for dispersion compensation based on vestigial-sideband transmission of an orthogonal frequency division multiplexed signal through standard signal-mode fiber with a direct-detection receiver. This technique requires simpler optical components and can withstand greater link attenuation and splitting ratios than similar methods previously studied, making the method ideal for optically unamplified receivers, such as those in passive optical networks. We present simulations as well as experimental measurements to demonstrate its practicality.

Optical Channel Monitor With High Resolution Capability

Abstract: Described herein is an optical channel monitor ( 1 ) including one or more input optical ports ( 3 ) for receiving an input optical signal ( 5 ) including a plurality of optical channels. A first monitoring module ( 7 ) is configured to selectively scan a predetermined spectral region of the optical signal including at least one optical channel for low resolution monitoring. A second monitoring module ( 11 ) is configured to simultaneously scan a subregion within the predetermined spectral region for high resolution monitoring.

Digital quadrature amplitude modulation with optimized non-rectangular constellations for 100 Gb/s transmission by a directly-modulated laser.

Abstract: We study the performance of novel quadrature amplitude modulation (QAM) constellations for 100 Gb/s transmission by a directly-modulated laser. Due to the strong nonlinearity of a directly-modulated laser, rectangular constellations suffer a large penalty from their regular spacing between symbols. We present a method for synthesizing irregular constellations which position symbols more efficiently. We will demonstrate the improved performance of these novel constellations over the conventional rectangular constellation as well as the superior performance achievable with digital QAM compared to optimally bit-loaded discrete-multitone modulation.

Multi-channel transceiver with laser array and photonic integrated circuit

Abstract: A laser module can include: a laser chip having a plurality of laser diodes; a focusing lens optically coupled to each of the plurality of distinct laser diodes; and a photonic integrated circuit (PIC) having a plurality of optical inlet ports optically coupled to the plurality of laser diodes through the focusing lens. The laser module can include an optical isolator optically coupled to the focusing lens and PIC and positioned between the focusing lens and PIC. The laser chip can include a fine pitch laser array. The laser module can include a plurality of optical fibers optically coupled to an optical outlet port of the PIC. The laser module can include a hermetic package containing the laser chip and having a single focusing lens positioned for the plurality of laser diodes to emit laser beams there through.

The evolution of 850nm VCSELs from 10Gb/s to 25 and 56Gb/s

Abstract: VCSELs are now being commercially deployed in applications up to 28Gbps. This paper will present a review of current VCSEL and PD capability and explore the technology development required to extend operation to even higher data rates.

Pluggable optical host and network i/o optoelectronic module

Abstract: In an embodiment, a pluggable optical host and network I/O optoelectronic module (hereinafter "module") includes a first optical-electrical-optical (OEO) converter and a second OEO converter. The first OEO converter is configured to convert N inbound optical signals to M inbound optical signals and includes N network-side optical receivers, first signal processing circuitry communicatively coupled to the N network-side optical receivers, and M host-side optical receivers communicatively coupled to the first signal processing circuitry. The second OEO converter is configured to convert M outbound optical signals to N outbound optical signals and includes M host-side optical receivers, second signal processing circuitry communicatively coupled to the M host-side optical receivers, and N network-side optical receivers communicatively coupled to the second signal processing circuitry.

Rapid out-of-band signal communication in optical components

Abstract: An example embodiment includes an optoelectronic module. The optoelectronic module may be configured to transmit out-of-band (OOB) data as an average optical power difference between optical signals. The optoelectronic module may include a first optical source, a second optical source, and an optical power control device. The first optical source may be configured to generate a first optical signal including first channel payload data on a first optical channel. The second optical source may be configured to generate a second optical signal including second channel payload data on a second optical channel. The optical power control device may be configured to vary average optical powers of one or more of the first optical signal and the second optical signal to create an average optical power difference between the first optical signal and the second optical signal that is representative of a logical bit of the OOB data.

Gigabit Access Passive Optical Network Using Wavelength Division Multiplexing—GigaWaM

Abstract: This paper summarizes the research and technical achievements done under the EU project GigaWaM. The goal of this project was to develop a cost-effective solution that can meet the increasing bandwidth demands in access networks. The approach was to use a novel wavelength division multiplexing passive optical network (WDM-PON) architecture that can deliver symmetric 1 Gb/s to 64 users over 20 km standard single mode fiber using the L and C bands for down and upstream, respectively. During the course of the project, a number of key enabling technologies were developed including tunable transceivers, athermal 50 GHz spaced arrayed waveguide grating multiplexer devices, novel hybridization technologies for integration of passive and active electro-optic devices, and system-level algorithms that ensure the quality of service. The outcome of the project proved a reliable, cost-effective, flexible, and upgradable WDM-PON solution, achieving per-user datarates of 2.5 and 10 Gb/s for up and downstream, respectively. The proposed solution is not only suitable for access networks, but also for metro aggregation and mobile backhaul.

Method of monitoring an optoelectronic transceiver with multiple flag values for a respective operating condition

Abstract: An optoelectronic transceiver includes an optoelectronic transmitter, an optoelectronic receiver, memory, and an interface. The memory is configured to store digital values representative of operating conditions of the optoelectronic transceiver. The interface is configured to receive from a host a request for data associated with a particular memory address, and respond to the host with a specific digital value of the digital values. The specific digital value is associated with the particular memory address received from the host. The optoelectronic transceiver may further include comparison logic configured to compare the digital values with limit values to generate flag values, wherein the flag values are stored as digital values in the memory.

Multiplexer/demultiplexer based on diffraction and reflection

Abstract: Transmissive diffraction grating(s), reflector(s), and multiple optical sources/receivers are arranged such that each one of multiple optical signals at corresponding different wavelengths co-propagating along a multiplexed beam path would: (i) be transmissively, dispersively diffracted at a multiplexed transmission region of a grating; (ii) propagate between the multiplexed transmission region and multiple demultiplexed transmission regions of a grating undergoing reflection(s) from the reflector(s); (iii) be transmissively, dispersively diffracted at the demultiplexed transmission regions; and (iv) propagate between the demultiplexed transmission regions and the sources/receivers along multiple demultiplexed beam paths.

Blind equalization tap coefficient adaptation in optical systems

Abstract: A method of blind tap coefficient adaptation includes receiving a digital data signal including random digital data, equalizing a first portion of the digital data signal using a first set of predetermined tap coefficients and a second portion of the digital data signal using a second set of predetermined tap coefficients. The method includes generating a first eye diagram and a second eye diagram from a first portion and a second portion of an equalized signal, respectively. The first eye diagram is compared with the second eye diagram to determine which of the sets of predetermined tap coefficients results in a data signal having a higher signal quality. The method includes inputting to an equalizer as an initial set of tap coefficients the first set of predetermined tap coefficients or the second set of predetermined tap coefficients according to the determination.

Latch mechanisms for modules

Abstract: Latch mechanisms for modules are disclosed. A module includes a housing and a release slide. The housing includes a first rib located on a first side of the housing and a second rib located on a second side of the housing. The release slide is slidingly positioned on the housing. The release slide includes a release slide base, a first release slide arm extending from the release slide base, and a second release slide arm extending from the release slide base. A first flange extending from the first release slide arm is positioned at least partially over the first rib. A second flange extending from the second release slide arm is positioned at least partially over the second rib.

Taking Optics to the Chip: From Board-mounted Optical Assemblies to Chip-level Optical Interconnects

Abstract: Board-mounted optical assemblies (BOAs) enable significant bandwidth density increase relative to pluggable optics at the card edge. We discuss the challenges for the next step in this evolution as optics moves towards the chip.

Flexible real-time transmitter at 10 Gbit/s for SCFDMA PONs focusing on low-cost ONUs

Abstract: We demonstrate, to the best of our knowledge, the first real-time single-carrier frequency division multiple access transmitter designed to be used in photonic communication networks. It is capable of providing 10 Gbit/s net bitrate at 3.125 GHz slot bandwidth, providing data to nine quasi-Nyquist spectral groups. The transmitter is designed with respect to logic efficiency and a fine user grid allowing the operation of narrow bandwidth, low-cost optical network units. Moreover, it offers runtime flexibility, an efficient 96-point discrete Fourier transform and a multiplier-free differential phase encoder. The article concludes with a presentation of the transmitters hardware setup and an evaluation of its performance in the case of direct electrical AWG-ONU Rx interconnection and the optical back-to-back case.

Optical circulators integrated into transceivers

Abstract: An optical circulator integrated into a transceiver for bi-directional communication may include a core configured to pass a transmission signal in a transmit direction and a received signal in a receive direction. The optical circulator may include an input port optically coupled to the core. The input port may be configured to deliver the transmission signal to the core. The optical circulator may include an output port optically coupled to the core. The output port may be configured to receive the received signal from the core. The optical circulator may additionally include a network port optically coupled to the core. The network port may be configured to receive the transmission signal from the core and deliver the transmission signal to a fiber optic cable. The network port may be configured to receive the received signal from the fiber optic cable and deliver the received signal to the core.

Optically enabled multi-chip modules

Abstract: An optically enabled multi-chip module has an optical engine transceiver and a host system chip. The optical engine transceiver has an optical engine front-end and an optical engine macro. The optical engine front-end has multiple laser diodes, laser driver circuitry electrically interfaced with each of the laser diodes, multiple photodiodes, amplifier circuitry electrically interfaced with each of the photodiodes, and at least one optical element optically positioned between the laser diodes and at least one optical fiber and between the photodiodes and the at least one optical fiber. The at least one optical element optically interfaces the laser diodes and photodiodes with the optical fiber. The optical engine macro is both electrically interfaced with and physically segregated from the optical engine front-end. The optical engine macro provides a subset of optical transceiver functionality to the optical engine front-end. The host system chip is electrically interfaced with the optical engine transceiver.

Ultrafast high resolution optical channel monitor

Abstract: Described herein is an optical channel monitor ( 1 ) including a protective housing ( 3 ), an input port ( 5 ) disposed in the housing ( 3 ) and configured for receiving at least one input optical signal ( 7 ) including one or more optical channels separated by wavelength. A wavelength configurable laser ( 9 ) is located within the housing ( 3 ) and is configured to provide an optical reference signal ( 11 ) at a first wavelength (λ r ). The laser ( 9 ) is adapted to scan across a range of wavelengths covering the one or more optical channels. An optical mixing module ( 13 ) is coupled to the input port ( 5 ) and the laser ( 9 ) for mixing the input optical signal ( 7 ) with the optical reference signal ( 11 ) to produce a mixed output signal. A receiver module ( 15 ) is configured to receive the mixed output signal and extract signal information indicative of at least the optical power of the at least one input optical signal at the first wavelength (λ r ).

Rigid-flexible circuit interconnects

Abstract: In an example embodiment, a circuit interconnect includes a first printed circuit board (PCB), a second PCB, a spacer, and an electrically conductive solder joint. The first PCB includes a first electrically conductive pad. The second PCB includes a second electrically conductive pad. The spacer is configured to position the first PCB relative to the second PCB such that a space remains between the first PCB and the second PCB after the first electrically conductive pad and the second electrically conductive pad are conductively connected in a soldering process. The electrically conductive solder joint conductively connects the first electrically conductive pad and the second electrically conductive pad.

N×N optical switch

Abstract: An optical cross-connect connecting a series of optical input ports to a series of optical output ports includes at least a first group of input/output port arrays, each including a series of optical input/output ports disposed horizontally and configured to project or receive optical signals. A plurality of steering elements selectively steer optical signals along switching trajectories between the input and output ports. An angle-to-offset conversion unit converts optical signals propagating at the horizontal intra-array angles to corresponding spatial offset signals in the horizontal dimension. An optical interconnect includes a series of input/output regions, each being specific to a corresponding input/output port array and the input/output regions being divided vertically into elongated switching rows. Each input/output region receives spatial offset signals from the angle-to-offset conversion unit and optically interconnects each spatial offset signal from a first input/output region to a second input/output region.

Systems And Methods of Aberration Correction In Optical Systems

Abstract: Described herein is a diffraction grating (1) for use in an optical system. The diffraction grating includes a substrate (2) and an array of elongate diffracting elements (3) arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Additive Manufacturing of Metallic Alloys

Abstract: Additive processes have gained increasing interest within the discussion of digital fabrication and architecture. In general, architects have encouraged limited implementation of this relatively new mode of production beyond conceptual and representational applications. Few examples exist that pursue the large scale application of this technology and these few cases are primarily focused on utilizing polymer and resin-based materials, ceramics, sand and cementitious materials. While additive manufacturing of metals has reached production scaled efficiency and cost feasibility within medical, aerospace, and aviation manufacturing industries, it has yet to make a significant presence as part of architectural discourse. This chapter presents two additive methods of manufacturing in metals most commonly employed for production and their possible applications within the architectural project. The research presented explores the expanded territory for design freedoms, as well as the higher degree of optimizations unique to this manufacturing process. In addition target areas are defined for implementation within a fully integrated design to manufacturing solution space.