Learning Forum

[Shin-Sung Kim]

 

[Shin-Sung Kim]

Other diverging situations 1. Material fits with unphysical gain Occasionally, the fitting routine will generate fits with gain, even though the experimental material data does not have any gain. This will cause a simulation to diverge even if the frequency at which the fit has gain is well outside of the simulation region. To check if this is the case: open the material editor, select show extended-spectrum and fit and plot the index. If Im(index) is negative at some point then there will be a small region of gain. This problem can be solved either by slightly varying the simulation bandwidth or by changing the fit tolerance and maximum coefficient variables. 2. Incorrect simulation setup Injecting a source with incompatible simulation region settings such as injecting a plane wave source with PML boundaries at the sides of the source can also cause a simulation to diverge. Automatic divergence checking Lumerical software has an automatic divergence checking feature. If the total energy in the simulation volume is many times larger than the injected energy, the simulation will be stopped. The following graphical warning shown will appear in the Job Manager and Object tree when a diverging simulation is detected. Capture.PNG The automatic divergence checking feature properties are found in the Advanced tab of the Simulation region properties. Time and movie monitors can be helpful when debugging diverging simulations. Both will show the fields growing exponentially at some point. Simulations that suddenly become very slow (for example, the time remaining estimate increasing from 5 minutes to 1 hour) is another sign of divergence. The automatic divergence checking normally stops the simulation before the simulation becomes very slow.

[liu]

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Sometime the autoshutoff level will increase to larger than 1 and then decrease. Is this okay for the simulation?

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[Shin-Sung Kim]

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The auto-shutoff level can occasionally go over 1. As long as the simulation terminates by reaching the specified "auto shutoff min" value, there is nothing to worry about.

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[s2106901]

how to solve this?

[kghaffari]

Please refer to the link below instead for information about troubleshooting Diverging Simulation, Thank you.

https://optics.ansys.com/hc/en-us/articles/11277217507603