How to build a model of thermal phase shifter?



I want to build an interconnect model of Thermal phase shifter? I could not find a related topic. Where should I start ?


This thermally tunable waveguide model is built based on MODE Solutions ans DEVICE simulation results.
Here is an example test file:thermally_tuned_waveguide.icp (470.6 KB)
Model Development

Parameter extraction
Please refer to the [Thermally Tuned Waveguide] ( ) page for detailed information on the component level simulations using DEVICE and MODE Solutions. All the files mentioned below can be found in the LCML_resource folder in the download page.

  1. Open the project file thermal_tuning_waveguide_2D.ldev in DEVICE and run with the default settings. The temperature distribution profile will be saved to T.mat .
  2. Open the project file thermal_tuning_waveguide_2D.lms in MODE Solutions and disable the “temperature” object. Run a frequency sweep and export the mode data to `thermal_tuning_waveguide.ldf" for INTERCONNECT.
  3. Run the script file thermal_tuning_waveguide_sweep.lsf . This will extract the effective index changes vs. temperature (input power) and save the data in thermally_tuned_wg_neff_power.dat .

The thermally tunable waveguide has an internal circuit that is very similar to that of the [PN phase shifter] (LCML - Phase shifter based on PN junction | lcml_ps_pn_1550), except that the Optical Modulator Measured element now uses the effective index perturbations as a function of the heating power ( thermally_tuned_wg_neff_power.dat ). The electrical input is voltage, and assuming the resistance is 50 ohm, the voltage is converted to power through an Electrical Multiplier and an Electrical Constant Multiplier (gain = 0.02).


Download the simulation file thermally_tuned_waveguide.icp from the top of this page. In this simulation file, the thermally tuned waveguide is measured by an Optical Network Analyzer (ONA). Run the sweep object “sweep_voltage” defined in the file. The following plot is the phase shift in the waveguide under different heating power (represented by driving voltage) at 193.1 THz.


Hope this helps!


Thank you very much!


I am glad that it was helpful!


Hi, I have some question about this example.
Why the phase is a negative value at voltage=0V. In the thermally tuned waveguide case, the phase-power curve is like as follows,

I think it’s reasonable to have a positive phase value when the applied voltage is zero.
Is there anything I missed?


Hi @lishifeng,

The phase value is wrapped in the range of [-pi, pi]. You can transfer this to positive phases by adding 2*pi to the result.