We are happy to announce that starting with the XMODEL development release 2020.0221, you can simulate silicon photonics systems that include both photonics and electronics with XMODEL. XMODEL includes a set of new primitives under a category called ‘siph’ as listed below:

• siph_waveguide: an optical waveguide element.
• siph_phshifter: an optical phase shifter element.
• siph_dircoupler: an optical directional coupler.
• siph_term: an optical termination element.
• siph_cwlaser: a continuous-wave laser source.
• siph_phdetector: a photodetector element.
• siph_ringres: an optical ring resonator.
• siph_ringres_var: an optical ring resonator with modulation input.
• siph_ringfilter: an optical ring resonator filter.
• siph_ringfilter_var: an optical ring resonator filter with modulation input.

As you expected, the XMODEL’s unique signal representation and event-driven simulation algorithm are the key to the fast and accurate, event-driven simulation of photonic components with full-band optical signals propagating bi-directionally. The basic challenge of simulating optical signals lies in the fact that they are at extremely high frequencies; for example, a 1550nm-wavelength laser has a 192THz frequency! This is a reason why some prior models used the baseband equivalent form for the optical signals. However, the baseband equivalent form has a drawback that it is effective only when the signal contains only one wavelength or frequency component. In comparison, the functional expression used by XMODEL to represent a signal is a superset of the baseband equivalent form and can support multiple wavelengths or frequencies.

By simply putting together these XMODEL primitives, you can compose a silicon photonics system model that expresses the optical signals in this functional expression form and processes them in a highly-efficient, event-driven manner in SystemVerilog. The figure below shows the waveforms of an electrical signal modulating a ring resonator, the modulated optical signal at the output of the ring resonator, and the output of a photodetector sensing the power of the optical signal. Note that XMODEL simulates the full-band optical waveforms, yet the number of events triggered during the SystemVerilog simulation is very few.

The figure below illustrates the model of a 5-channel wavelength-division multiplexing (WDM) optical link modeling using the new XMODEL’s siph primitives. On the transmitter side, each of five ring resonators tuned at different resonant frequencies modulates a different wavelength of laser, namely, 1475, 1480, 1485, 1490, and 1495nm, depending on the binary data streams. On the receiver side, each of five ring resonator filters again tuned at different resonant frequencies channels a different wavelength optical signal to its output, which is then converted to an electrical output signal by a photodetector.

This model takes 80 seconds to run a 10ns-long simulation. The figure below shows the waveforms of the wavelength-division multiplexed optical signal at the transmitter output and each of the five optical signals observed at the ring resonator filter outputs. Again, all the optical signals are full-band signals, but triggering very few number of events during the SystemVerilog simulation.

Finally, the last figure compares the waveforms of the 5-channel input data and output data. Besides the fact that output data take smooth, continuous-time waveforms, their information matches well with the information of the input data.

We are happy to announce that starting with the XMODEL development release 2020.0221, you can simulate silicon photonics systems that include both photonics and electronics with XMODEL. XMODEL includes a set of new primitives under a category called ‘siph’ as listed below:

• siph_waveguide: an optical waveguide element.
• siph_phshifter: an optical phase shifter element.
• siph_dircoupler: an optical directional coupler.
• siph_term: an optical termination element.
• siph_cwlaser: a continuous-wave laser source.
• siph_phdetector: a photodetector element.
• siph_ringres: an optical ring resonator.
• siph_ringres_var: an optical ring resonator with modulation input.
• siph_ringfilter: an optical ring resonator filter.
• siph_ringfilter_var: an optical ring resonator filter with modulation input.

As you expected, the XMODEL’s unique signal representation and event-driven simulation algorithm are the key to the fast and accurate, event-driven simulation of photonic components with full-band optical signals propagating bi-directionally. The basic challenge of simulating optical signals lies in the fact that they are at extremely high frequencies; for example, a 1550nm-wavelength laser has a 192THz frequency! This is a reason why some prior models used the baseband equivalent form for the optical signals. However, the baseband equivalent form has a drawback that it is effective only when the signal contains only one wavelength or frequency component. In comparison, the functional expression used by XMODEL to represent a signal is a superset of the baseband equivalent form and can support multiple wavelengths or frequencies.

By simply putting together these XMODEL primitives, you can compose a silicon photonics system model that expresses the optical signals in this functional expression form and processes them in a highly-efficient, event-driven manner in SystemVerilog. The figure below shows the waveforms of an electrical signal modulating a ring resonator, the modulated optical signal at the output of the ring resonator, and the output of a photodetector sensing the power of the optical signal. Note that XMODEL simulates the full-band optical waveforms, yet the number of events triggered during the SystemVerilog simulation is very few.

The figure below illustrates the model of a 5-channel wavelength-division multiplexing (WDM) optical link modeling using the new XMODEL’s siph primitives. On the transmitter side, each of five ring resonators tuned at different resonant frequencies modulates a different wavelength of laser, namely, 1475, 1480, 1485, 1490, and 1495nm, depending on the binary data streams. On the receiver side, each of five ring resonator filters again tuned at different resonant frequencies channels a different wavelength optical signal to its output, which is then converted to an electrical output signal by a photodetector.

This model takes 80 seconds to run a 10ns-long simulation. The figure below shows the waveforms of the wavelength-division multiplexed optical signal at the transmitter output and each of the five optical signals observed at the ring resonator filter outputs. Again, all the optical signals are full-band signals, but triggering very few number of events during the SystemVerilog simulation.

Finally, the last figure compares the waveforms of the 5-channel input data and output data. Besides the fact that output data take smooth, continuous-time waveforms, their information matches well with the information of the input data.