Re: [Meep-discuss] Absorbed Photon Density in Meep
For your reference, we recently added a new tutorial example which demonstrates how to compute a density map of the absorbed power: https://meep.readthedocs.io/en/latest/Python_Tutorials/Basics/#absorbed-power-density-map-of-a-lossy-cylinder On 6/17/20 12:21, J. Philip Haupt wrote: Sorry to bother again. While I think this works, I have encountered some issues and am wondering if they're avoidable. Namely, when I use add_dft_fields the run time is substantially increased and when I use output_dft, the file size is tens of GB. I am ultimately interested in the total absorbed photon density (for all frequencies) of the cell integrated along the y axis. Is my best option using add_dft_fields (for the entire volume), calculating Im(ε(ω)) |E|^2/hω, then integrating both frequency and space along y? ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] Absorbed Photon Density in Meep
> On Jun 17, 2020, at 3:21 PM, J. Philip Haupt > wrote: > I am ultimately interested in the total absorbed photon density (for all > frequencies) of the cell integrated along the y axis. Is my best option using > add_dft_fields (for the entire volume), calculating Im(ε(ω)) |E|^2/hω, then > integrating both frequency and space along y? If you just want the total absorbed power at each point, integrated over frequency, it would be more efficient to integrate Re[E* dP/dt] (the work done on the polarization currents) over time at each point. I don't know offhand if there is an easy way in Meep to get access to the polarization currents, but this would be a nice feature to add. ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] Absorbed Photon Density in Meep
Hi, Sorry to bother again. While I think this works, I have encountered some issues and am wondering if they're avoidable. Namely, when I use add_dft_fields the run time is substantially increased and when I use output_dft, the file size is tens of GB. I am ultimately interested in the total absorbed photon density (for all frequencies) of the cell integrated along the y axis. Is my best option using add_dft_fields (for the entire volume), calculating Im(ε(ω)) |E|^2/hω, then integrating both frequency and space along y? Best, Philip On 2020-06-13 6:43 a.m., Steven G. Johnson wrote: You can use add_dft_fields to compute the Fourier-transformed electric field in some region. The absorbed energy density (for linear media) is then Im(ε(ω)) |E|^2 at each frequency ω at each point in the absorbing material. On Jun 12, 2020, at 10:06 PM, J. Philip Haupt wrote: Hello, I wish to calculate the absorbed photon density (as a function of space) in Meep, to be input to an electrical device simulation. Is there an efficient/quick way of doing this? The only method I can think of is to use output_poynting() to get the Poynting flux at every time step, then after the simulation time-average all of these fluxes, numerically find the divergence, and then finally divide by h*(frequency of photon). However, this seems like it would be very inefficient. Is there another approach (perhaps somehow using a FluxRegion object)? Best regards, Philip ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] Absorbed Photon Density in Meep
You can use add_dft_fields to compute the Fourier-transformed electric field in some region. The absorbed energy density (for linear media) is then Im(ε(ω)) |E|^2 at each frequency ω at each point in the absorbing material. > On Jun 12, 2020, at 10:06 PM, J. Philip Haupt > wrote: > > Hello, > > I wish to calculate the absorbed photon density (as a function of space) in > Meep, to be input to an electrical device simulation. Is there an > efficient/quick way of doing this? The only method I can think of is to use > output_poynting() to get the Poynting flux at every time step, then after the > simulation time-average all of these fluxes, numerically find the divergence, > and then finally divide by h*(frequency of photon). However, this seems like > it would be very inefficient. Is there another approach (perhaps somehow > using a FluxRegion object)? > > Best regards, > Philip > > ___ > meep-discuss mailing list > meep-discuss@ab-initio.mit.edu > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
