Today is great day to be in the field of designing and manufacturing optical networking and communications equipment.
One reason is that today marks the opening of OFC 2015 taking place this week in Los Angeles. OFC is the largest global conference and exposition for optical communications and networking professionals and always comes through with useful insights about the latest trends and technological advancement.
The other reason is that Tektronix is announcing two new test and measurements solutions – available for live demos at OFC – that are sure to put a smile on the faces of optical designers and researchers working on 100G, 400G and even 1 TB products.
High-speed optical designs require bandwidth. Lots of it. And Tektronix is delivering with the introduction of the DPO70000SX ATI Performance Oscilloscope with 70 GHz bandwidth and the OM4245 45 GHz Optical Modulation Analyzer capable of dual-polarization coherent optical analysis up to 80 Gbaud. Both instruments work closely together to provide digitization of complex modulation signaling for testing coherent optical transmitters, transmission systems, and receivers.
Until now, researchers and engineers have needed to turn to multiple test and measurement vendors or even build their own test fixtures to perform required tests, costing valuable research time and reducing repeatability. With today’s introductions, Tektronix has now solved the industry-wide problem of how to efficiently test coherent modulation technologies.
High-speed modulation analysis
Let’s start by looking at the OM4245. The high-speed modulation analyzer offers built-in, narrow linewidth lasers and supports the Tektronix OM-Series User Interface (OUI). Along with proven ease-of-use for typical analysis applications, the Tektronix OUI also provides the flexibility and access to the MATLAB computational engine researchers need for more advanced coherent optical analysis. This provides a robust, time-saving, and customizable platform for conducting experiments in coherent modulation algorithms.
For analysis beyond 400G, the OM4245 offers Multi-Carrier Support (option MCS) that delivers automated analysis for any configuration of multi-carrier systems including 800G and 1Tb architectures.
The new OM4245 45 GHz Optical Modulation Analyzer is capable of dual-polarization coherent optical analysis up to 80 Gbaud.
Ultra-high bandwidth
Of course, the analyzer is only part of the story. You also need an acquisition system with performance to keep up. With the DPO70000SX, Tektronix delivers an ultra-high bandwidth of 70 GHz, along with a real-time sample rate of 200 GS/s (5ps/sample resolution), making it ideal for high-speed optical measurements as well as many other applications such as high-energy physics research and high-speed serial.
Contained in a compact 5.25-in. instrument package, the DPO70000SX as shown below can operate either as a single channel system with 70 GHz, 200 GS/s sample rate, or as a two-channel system, each with 33 GHz, 100 GS/s sample rate.
The DPO70000SX series unit is a compact 5.25 inches tall, allowing it to fit in a standard 3U rack space.
A precision timing synchronization technology from Tektronix called UltraSync establishes the precise channel-to-channel timing stability needed for high performance multichannel measurement systems. Up to four DPO70000SX units are able to operate together as one unit while delivering the same level of measurement precision and usability as a standalone (monolithic) oscilloscope.
With its compact form factor and UltraSync technology, along with several other new innovations including Asynchronous Time Interleaving technology (ATI), the DPO70000SX offers unprecedented levels of performance, flexibility and scalability.
As detailed in the Tektronix white paper “Techniques for Extending Real-Time Oscilloscope Bandwidth,” ATI is a unique method for digitizing the full input signal spectrum. It features signal path symmetry that preserves signal-to-noise ratio for higher fidelity. The entire input signal is digitized by each of two symmetrical acquisition paths and reassembled with a patented method that preserves the signal and reduces noise.
The DPO70000SX is designed to fit in a 3U rack space. It is significantly smaller than other oscilloscopes in the ultra-high bandwidth class. Despite its small physical dimensions, each DPO70000SX unit delivers the full range of features and functionality of traditional bench oscilloscopes. It comes with the same advanced capabilities for jitter analysis, signal path de-embedding or spectral analysis as the MSO/DPO70000 oscilloscopes do today, and can take advantage of the full range of software solutions, probes, fixtures, and other accessories.
In today’s world, engineers are increasingly opting to connect oscilloscopes to large, inexpensive flat-screen monitors or take advantage of remote access capabilities. As such, the built-in monitor is used only infrequently. Of much greater concern is the ability to shorten the signal path between the DUT and the oscilloscope’s input.
The combination of the compact packaging and the UltraSync interface meets this objective. As shown in the graphical depiction below, instruments can be placed face-to-face with an OM4245 to enable the use of very short cables, all of the same length. In this example, the bottom units have been inverted to position the center inputs very close to each other.
Graphical depiction of four DPO70000SX units and an OM4245 Optical Modulation Receiver positioned face-to-face for 400G coherent optical modulation applications.
UltraSync provides a high-speed network that coordinates triggers across a multi-instrument acquisition system with inherent channel-to-channel jitter <500fs rms, typical. This means that when multiple DPO70000SX units are connected together with UltraSync cables they offer the functional equivalent of a single high performance oscilloscope with multiple high-speed channels. For instance, a two-unit system synchronizes two units to provide two channels at 70 GHz, 200 GS/s, or four channels at 33 GHz, 100GS/s.
In addition to supporting the needs of high-speed optical researchers, UltraSync offers considerable advantages around scalability. For scaling up a lab could invest sequentially in oscilloscope systems as performance or channel count needs change. Conversely, systems can easily be scaled down with multiple units divided and redeployed to other projects as needed, maximizing the use of a capital investment.
UltraSync is very easy to set up and configure. Any unit can act as the master or extension unit, which is determined by how UltraSync cables are connected and the designation is easy to change by simply moving cable connections. A graphical configuration manager as shown below helps validate cable connections and indicates channel identities. Once the connections are in place, the oscilloscopes automatically establish the network and determine timing relationships across units.
The UltraSync configuration manager coordinates multi-unit startup and verifies connections.
It should be noted that this flexibility is missing in multi-unit systems offered by other vendors. For example, the LeCroy 10Zi, requires a separate controller unit for system operation and the master and extension units are pre-configured at the factory and cannot be separated by the user.
Tektronix offers the option of purchasing two DPO70000SX series units configured together as the DPS70000SX oscilloscope system at a significant discount. The DPS77004SX system provides two 70 GHz channels at 200 GS/s, which is ideal for applications like differential high speed serial signal analysis. Two DPS77004SX systems can be configured and operated together to provide a multi-unit system with a total of four 70 GHz channels. The DPS73308SX provides four 33 GHz channels at 100 GS/s, useful for applications such as dual polarization coherent optical modulation analysis.
For engineers who are used to having a front panel, an optional Auxiliary Front Panel is available which provides user controls that are identical to the controls and indicators provided on the Tektronix DPO7000 and MSO/DPO70000 series oscilloscopes. The AFP allows users to fully control the DPO70000SX from a convenient location and at the same time position the oscilloscope optimally for signal acquisition.
We hope you’re as excited as us (and we imagine many OFC attendees) about these new product introductions and the significant advances they represent for ultra high-performance measurement. To learn more go here for the DPO70000SX and here for the OM4245.