Especially noteworthy are modelling enhancements and usability improvements related to the simulation of multimode fibre based transmission systems, including support for spatial division multiplexing applications and short-reach applications in data centres, for instance. Important new capabilities include:
• Means for detailed multimode fibre modelling considering not only linear dispersive effects, but also self-phase and inter-/intramodal cross-phase modulation caused by the Kerr nonlinearity
• Macro to apply directly typical parameter values of OM1, OM2, OM3, or OM4 fibers according to the ISO/ IEC 11801 standard
• Support of binary Zemax beam files (.zbf) to describe an optical beam and calculate the coupling coefficients between this beam and a multimode fibre or waveguide
• Accurate accounting for the spectral dependence of the fibre index profile by the fibre mode solver, which can significantly improve differential group delay calculations
• Enhanced multimode system-level amplifier model to support the individual definition of wavelength-dependent gain and noise characteristics for different spatial modes
• Enhanced support of multimode signal analysis functions in VPIphotonicsAnalyzer
Furthermore, VPItransmissionMaker Optical Systems and VPIlabExpert Version 9.5 are compatible with the Version 2.0 of VPItoolkit DSP Library, a pluggable toolkit providing access to an extensive collection of lab-proven DSP algorithms developed by the Photonic Networks and Systems department at Fraunhofer Heinrich-Hertz Institute. This new version of the DSP Library provides significant functionality upgrades including the support of data-aided frequency domain equalisation using, for example, CAZAC sequences, and means for off-line processing of experimental data.
Additonal features of Version 9.5 include:
• New transmitter for polarization-multiplexed optical signals with arbitrary quadrature modulation performing normalisation and predistortion, analogue pulse shaping and emulation of imperfect D/A converter responses
• New DSP algorithms for coherent systems including deskewing, digital back propagation, and an stability-improved TDE-MIMO algorithm
• Estimation of the effective number of bits of an ADC in presence of distortions such as jitter and differential nonlinearities
• Enhanced lab equipment module Tek_AWG_70002A to support not only sockets for communication with the device, but also the VXI-11 protocol
• Enhanced photonics multisection device modelling with the PhotonicsTLM module by supporting customisable discretisation sizes of device sections
• Flexible format signal analyser supporting the automated characterization of relative intensity noise in lasers
• New module to deliver the differences between two optical or electrical signals within a specified tolerance to automate optimisations and help to manage complex simulations
• Enhanced GUI to ease handling of and navigation through resources and simulation schematics
• Increased capabilities of parameter and user interface scripting using Python
