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Crosstalk Noise, Jitter, Channel Loss

This paper addresses a new methodology for 12 Gbps interoperability that combines a concerted family of pathological channels, internal eye monitoring, and external EQ simulation tools, providing insight into an EQ optimization strategy that addresses the specific channel’s mix of crosstalk noise, jitter, and channel loss. This also provides a backplane designer the ability to configure a high-loss, crosstalk aggressed system.


A single-polarization 160-Gb/s (80-Gbaud) electronically time-division-multiplexed (ETDM) quadrature phase-shift-keyed (QPSK) signal is generated and coherently detected using two 45-GHz-bandwidth oscilloscope prototypes and offline processing.

We present a novel low-loss 3-spot mode coupler to selectively address 6 spatial and polarization modes of a few-mode fiber. The coupler is used in a 66 MIMO-transmission experiment over a 154-km hybrid span consisting of 129-km depressed-cladding and 25-km graded-index few-mode fiber.

Low differential group delay

Low differential group delay (DGD) between the modes of a graded-index few-mode fiber is obtained by combining segments with DGD of opposite sign. Transmission of mode-multiplexed 620-GBd QPSK over a record distance of 1200 km is demonstrated.


We experimentally demonstrate 8 dB of mode-equalized distributed Raman gain using a backward pumping scheme. The equivalent noise figure of the amplifier is -1.5 dB, and the amplifier was successfully employed to demonstrate 6-channel mode-multiplexed MIMO transmission over 137-km few-mode fiber.

Sampe Rates, Oscilloscopes

Enhanced Sample Rate, combined with the low-noise system architecture and the tailored brick-wall frequency response in the HDO4000A, HDO6000A, HDO8000A and MDA800A series oscilloscopes dramatically improves the measurement precision when the input frequency signals are very high frequency, such as a high-frequency sine wave or fast edge.

Automated Test Systems, ATE

Defining an automated test system can be challenging: the goal of a test system architect is to accelerate the test system design process, ensure that the system can be easily deployed and sustained throughout the product life cycle and, of course, all while maintaining test quality.

Pickering’s unique approach to solving challenges associated with signal switching and routing implementations will be presented in this white paper. Still, many of the thought processes and guidelines can be applied to other aspects of your test system, regardless of supplier. 

In this white paper, you will also learn about the benefits of a well-defined test development process and strategies to accelerate and achieve an optimized, automated test methodology. Details include:

  • The Current State of the Industry
  • Common Challenges Customers Face
  • Strategies and Considerations to Accelerate Integration
  • Pickering Interfaces’ Test Integration Solutions
  • And More

Many tools are available to help integrate test systems and speed test system development. This white paper has focuses on ways to make the integration phase of a test system project more efficient and easier. However, Pickering offers products, support and guidance across a test system’s entire lifetime.

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We experimentally demonstrate transmission of 6 mode-multiplexed 20-Gbd-QPSK signals over 1200 km of three-core microstructured fiber (3C-MSF). An aggregate single-wavelength capacity of 240 Gbit/s is recovered by off-line 66 coherent multiple-input multiple-output (MIMO) digital signal processing.

Multiplexed Transmissions

We demonstrate 12 x 12 multiple-input multiple-output mode multiplexed transmission over 130-km of few-mode fiber of a combined 6-space-, 2-polarization-, and 8-wavelength-division multiplex, using low-loss photonic lantern and 3D-waveguide mode multiplexers.

NRZ-encoded Signals, Manchester-encoded Signals

The industry's first NRZ and Manchester configurable protocol decoders accept a broad range of physical characteristics for NRZ- or Manchester-encoded signals.

We experimentally demonstrate multiple-input-multiple-output transmission of a combined 3-space-, and 2-polarization-, and 5-wavelength-division multiplex in a 3-core microstructured fiber over 4200 km. This is the record transmission distance for spatial-division multiplexing in a fiber.

Digital Signal Processing

We transmit 32 WDM channels over 12 spatial and polarization modes of 177 km few-mode fiber at a record spectral efficiency of 32 bit/s/Hz. The transmitted signals are strongly coupled and recovered using 12 x 12 multiple-input multiple-output digital signal processing.

S-Parameters, Continuous Frequency Responses

We explore in detail the relationship between discrete-frequency responses connected with sparameters and the implied continuous time response. This is done in both the frequency- and time-domain to develop the proper insight and explore issues with real time-domain responses, time-aliasing, causality, interpolation and re-sampling of discrete-frequency data. Using the insight gained, we identify the conditions for sufficiency of sampling and the side-effects of the invariable practical conditions when these side-effects cannot be completely dispelled. This paper is especially useful for understanding issues involved in direct application of sparameters in linear simulations, like those used in virtual probing applications in scopes.


Technologies and design considerations are presented for the design of very high bandwidth oscilloscopes. These include chip, DSP and microwave technologies employed in some of the fastest waveform digitizers in the world.

Oscilloscopes, Signal Analysis

The oscilloscope has been a primary tool for electronic design engineers since the invention of that instrument, many years ago. The first decades of oscilloscopes were “analog” in nature.