Transient Heat Simulation Using FDTD Pabs as Import Heat Source
I am trying to use Lumerical FDTD alongside Lumerical HEAT to simulate the photothermal heating and cooling of a nanocylinder. Following from this example in plasmonic nanostructures (Photothermal heating in plasmonic nanostructures – Lumerical Support), I have first simulated a single nanocylinder on a substrate in FDTD with a TFSF laser source to determine the absorbed power(Pabs) (using the Pabs adv analysis group) within the cylinder. As in the example, I have been able to plot the spatial distribution of Pabs within the cylinder as a result of the laser.
My problem now is within HEAT, as I am struggling to adapt the example simulation to allow for transient heat simulations. Currently, I am able to use the FDTD Pabs data as the imported heat source, and I can simulate the temperature distribution as a result of this imported heat source, but only in a steady state situation. When I try to use the transient heat solver I am told there is an error; from my understanding, the only way to use the transient heat solver is to set a temperature of power boundary condition, choose 'bc mode: transient', and set a changing temp or power in timesteps (as detailed here: Transient heat flow in a graphene-coated glass – Lumerical Support).
In my situation, the aim is to import the Pabs data within the cylinder as a pulsed heat source, and to simulate the heating/cooling that occurs in time after the heat source, i.e., to import the Pabs data as a single source of energy rather than a rate/power. Is it possible to import the heat source as an energy and then plot the time-dependent heating and cooling as a result of this pulsed energy gain? I can see from the steady-state simulation the rough temperature that my nanocylinder should reach, so I can possibly make a crude estimate of the initial temperature and see how this changes in time through transfer to the substrate etc, but I am unsure how to go about this as I do not want to set my own transient temperature/power boundary condition.
Any help or advice is greatly appreciated! Thanks :)