Re: [Meep-discuss] GaussianBeamSource with Custom Source
The GaussianBeamSource is only a gaussian beam at a single frequency. To make an accurate spread-spectrum gaussian beam out of this, you'd have to do some kind of superposition, e.g. solve a fitting problem to find a superposition of narrow-band gaussian pulses whose sum is your desired time-dependent function. > On Dec 20, 2020, at 6:58 PM, Gui Max wrote: > > Hello, > > I am trying to use a custom source alone with the GaussianBeamSource. The > custom source is a laser pulse (looks like an up-chirped pulse). > Initially, I try to use this custom source without specifying the 'fcen'. > However, the field will diverge. > This issue was fixed by assigning a 'fcen' argument. > Since the chirped pulse changes the frequency over time, what should be the > correct 'fcen'? > Also, the 3D shape does not look like a beam when rotated(please see the > following picture). Did I do something wrong? Any help would be appreciated. > > > ___ > 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
[Meep-discuss] GaussianBeamSource with Custom Source
Hello, I am trying to use a custom source alone with the GaussianBeamSource. The custom source is a laser pulse (looks like an up-chirped pulse). Initially, I try to use this custom source without specifying the 'fcen'. However, the field will diverge. This issue was fixed by assigning a 'fcen' argument. Since the chirped pulse changes the frequency over time, what should be the correct 'fcen'? Also, the 3D shape does not look like a beam when rotated(please see the following picture). Did I do something wrong? Any help would be appreciated. [image: g.JPG] ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] GaussianBeamSource
Thank you very much, Steven. I didn't realize that my version is too old. I already have the new version. El dom., 1 nov. 2020 a las 13:04, Steven G. Johnson () escribió: > > > On Oct 31, 2020, at 12:20 PM, Alfredo Daniel Sánchez < > alfredo.daniel.sanc...@gmail.com> wrote: > > I realized that the GaussianBeamSource class is not defined in my meep > package. It is possible that it does'n exist anymore? In that case, how can > I generate one? > > This feature was added in Meep 1.16, so probably your Meep version is too > old. > > > ___ > 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] GaussianBeamSource
> On Oct 31, 2020, at 12:20 PM, Alfredo Daniel Sánchez > wrote: > I realized that the GaussianBeamSource class is not defined in my meep > package. It is possible that it does'n exist anymore? In that case, how can I > generate one? This feature was added in Meep 1.16, so probably your Meep version is too old. ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] GaussianBeamSource
Thank you very much, Ian. I'm going to perform your suggestions. El sáb., 31 oct. 2020 a las 15:06, Ian Sage () escribió: > You just need to apply an amp_func function to your source, with an > appropriate spatial profile. The function takes as argument a vector giving > the spatial offset from the centre of the source, allowing you to specify a > scaled exponential fall-off from the centre. You can also return a complex > amplitude to spatially vary the phase and steer the beam. > > It's pretty well covered in the documentation. > > Ian > On 31/10/2020 16:20, Alfredo Daniel Sánchez wrote: > > Hello everybody! > > I realized that the GaussianBeamSource class is not defined in my meep > package. It is possible that it does'n exist anymore? In that case, how can > I generate one? > > Best regards, > > Alfredo. > > ___ > meep-discuss mailing > listmeep-disc...@ab-initio.mit.eduhttp://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 ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Re: [Meep-discuss] GaussianBeamSource
You just need to apply an amp_func function to your source, with an appropriate spatial profile. The function takes as argument a vector giving the spatial offset from the centre of the source, allowing you to specify a scaled exponential fall-off from the centre. You can also return a complex amplitude to spatially vary the phase and steer the beam. It's pretty well covered in the documentation. Ian On 31/10/2020 16:20, Alfredo Daniel Sánchez wrote: > Hello everybody! > > I realized that the GaussianBeamSource class is not defined in my meep > package. It is possible that it does'n exist anymore? In that case, > how can I generate one? > > Best regards, > > Alfredo. > > ___ > 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
[Meep-discuss] GaussianBeamSource
Hello everybody! I realized that the GaussianBeamSource class is not defined in my meep package. It is possible that it does'n exist anymore? In that case, how can I generate one? Best regards, Alfredo. ___ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
