Solved

Results for high frequency approximations (Wave propagation)

  • 12 September 2021
  • 37 replies
  • 989 views
Show first post

37 replies

S
Rank
Userlevel 6
Badge +2

Hi Benoit,

Thank you for sharing your file.

Usually, when I am working with POP, I try to set the geometric rays to be quite similar to POP. There is no really need for that but I think it helps in terms of setting the system properly.

So in POP, the waist is 1mm in radius and starts at surface 1.

In the “geometric” definition, the beam starts from surface 0 and has a divergence angle (marginal ray) of 6.3 degrees. On surface 1, the beam has a radius of roughly 24mm.

So is the POP definition correct? Does the beam start on surface 1 or does it start at the object?

Let me know and then I’ll keep on working on it.

Sandrine Auriol
Plancoulaine

Hi Sandrine,

Thank you for your paper, I will look it with attention.

Yes, I study the “Pinhole Aperture” but I cannot generate good results. Your aperture is defined with “Cicular Aperture” and with “Maximum radius” 0.006. I changed this last parameter but I not succeeded!

Concerning the POP parameters, I attached another zip file to this exchange, I hope it is better! But, I can give you the parameters for POP:

- Settings→ Beam: Definition: Beam Type=”Astigmatic Gaussian”; X-Sampling=Y-Sampling=2048; X-Width=Y-Width=100; Waist X=Waist Y=1.

- Settings→ Display: Show As=Inverse Grey Scale (irradiance) or Grey scale (phase) or Cross X; Data=Irradiance or Phase.

I also remake the simulation with the Numerical Propagation plugin. I improved the contrast for amplitude and I use false color this time (please, see below).

Amplitude image
Phase image
Phase image (size x 6)

In particular, the center is dark because the wave is locally plane.

Have a good weekend, Benoît.

1 Attachment
S
Rank
Userlevel 6
Badge +2

Hi Benoit

Could you send the settings you used for POP? The easier is if you can save your file as an archive file (File...save as...zar) as it will contain everything needed.

I’ll have a look because when going through pinholes we often need to adjust the sampling for POP. There is a sample file here if you want to have a look: "{Zemax}\Samples\Physical Optics\Pinhole Aperture.ZMX".

You can see that the pilot beam is recalculated after the pinhole:
 

But sometimes the sampling needs to be changed too.

I have attached the article (sorry it is a copy and paste so the format is not great). The attachments can be found here.

Sandrine

1 Attachment
Sandrine Auriol
Plancoulaine

Hello Sandrine,

Thank you for your advises. However, I simulated circular obstruction in order to understand your propagation module.

 

This obstruction is built by a circular hole of 0,4 mm of diameter and it is viewed from 150 mm away.

The irradiance image and the phase image are given below (OpticStudio file is attached to this exchange).

Irradiance image

Diffraction profile

We watch the traditional diffraction profile.

Phase image

You can simulate the same issue with the “Numerical Wave Propagation” plugin by means to ImageJ software (Piedrahita-Quintero P, Castañeda R, Garcia-Sucerquia, Numerical wave propagation in ImageJ, J. Appl. Opt.; 54[21]:6410-5 (2015)). You also obtain the irradiance and phase image.

Irradiance image


Profile of the diffraction
 

Diffraction profile

We also watch the traditional diffraction profile (just a few difference scale due to the image resolution).


Phase image
 

Phase image

The “OpticStudio” simulation uses the astigmatic Gaussian beam propagation and the ImageJ plugin uses directly the Fresnel propagation. It seems to me the two phase images differ but the phase computation is perhaps different?

Yes, I am interested by your paper, thank you in advance.

I read some user guides of the OpticStudio software and I found two Zemax papers:

- Aumeyr (T.), Billing (M.G.), Bobb (L.M.), Bolzon (B.), Karataev (P.), Lefevre (T.), Mazzoni (S.), Zemax Simulations of Transition and Diffraction Radiation, J. Phys.: Conf. Ser. 517 012026 (2014).

- Ikeda (K.), Gay (S.), OpticStudio TrueFreeform TM optimization for complex illumination systems, Light-Emitting Devices, Materials, and Applications, Proceedings Vol. 11302 (2020).

Kind regards, Benoît.

1 Attachment
S
Rank
Userlevel 6
Badge +2

And I am not sure if it can be interesting for you but we have an old article (it is not published) about a macro written to render OpticStudio lens files in POV-Ray. Let us know if this is something you’d like and I can see to send it or update it?

Sandrine Auriol
S
Rank
Userlevel 6
Badge +2

Hey Benoit!

Thank you for sharing this. It is interesting.

For the phase, I have opened the file under "{Zemax}\Samples\Physical Optics\Axicon with ring focus.ZMX". In the POP window, you can simply ask to display the phase:

The phase is atan(Imaginary part of the electric field/real part). It is between +/-π.

At each surface, we have an array containing the complex electric field so the intensity and phase are calculated from this. There is another forum post that you may find interesting here: 

Otherwise if you search for POP on our KBA website https://support.zemax.com/hc/en-us/search?utf8=%E2%9C%93&query=pop, you will get some interesting articles that I would recommend reading if you are not too familiar with POP.

Sandrine

Sandrine Auriol
Plancoulaine

Hello Sandrine,

Yes, I found the way to simulated intensity using the “Physical Optics Propagation” module (I will surely illustrate these simulations in a future paper). Otherwise, I not found how obtain the phase, can you help me, please.

I built images from the Povray software of the biological simulations:

At the top, a nucleus for instance, in middle a lens (microscope) and at the bottom the image given by the lens.

Other biological elements without lens.

The Poveray is a good software but it is classical ray tracing. In particular, it seems to me the diffraction phenomena is lost (the photon module can reveal caustics only).

Have a good week-end, Benoît.

S
Rank
Userlevel 6
Badge +2

Hi Benoit

Physical Optics Propagation gives both the irradiance and phase of the beam. Can this work for your case?

Sandrine

Sandrine Auriol
Plancoulaine

Hello Sandrine,

No, I not uploaded attachment. You find attached the paper of the first message.

I began slowly the programming of the method of this paper (it is not my main activity) to study the light behaving in the biological tissues (I think it is surely interesting to have the intensity and phase image computed together).

Kind regards, Benoît.

1 Attachment
S
Rank
Userlevel 6
Badge +2

Hello Benoit

Sorry there is no attachment to your previous post. Is there supposed to be one?

Thank you.

Sandrine

Sandrine Auriol
Plancoulaine

Hello Hui,

Thank you for your precious information.

Yes, the physic propagation module (POP) gives very good irradiance images, no problem (I tested with the knife-edge). The pure geometric ray trace with the “Jacobi-Hamiltonian” and especially the “method of characteristics” is also very good to find the light rays and the phase on the wave surfaces. I think the two modules compute independently the results but perhaps, it is not exact.

Therefore, it not is very easy to establish directly relationships between the intensity and the phase. The very simple example attached shows the Gaussian beams with the intensity superposed with the phase which are computed together. In particular, we see enough well the Rayleigh length impact on the Gaussian beams.

Kind regards, Benoît.

Hui Chen
Rank
Userlevel 4
Badge +1

Hi Plancoulaine, 

OpticStudio provides 3 methods to model beam propagation. One is based on pure geometric ray trace. You can view the phase of the beam using the Wavefront map which shows you the optical path difference of a pupil ray relative to either the chief ray or the centroid. The second is the Paraxial Gaussian or the Skew Gaussian model.  The Paraxial Gaussian computes the propagation and transformation of a rotationally symmetric Gaussian beam using two paraxial rays in a meridional plane as given by Arnaud in "Hamiltonian Theory of Beam Mode Propagation” and Siegman in “Lasers”. The Skew Gaussian can model an off-axis propagation of the beam and the beam parameters are computed using real rays and account for astigmatism. The third method is the Physical Optics Propagation (POP) where the propagation is modeled by propagating wavefronts through your optical system. The physical optics model is generally more accurate at predicting the detailed amplitude and phase structure of the beam. You can find a detailed explanation on how POP works in the help documentation at The Analyze Tab (sequential ui mode) > Laser and Fibers Group > About Physical Optics Propagation.

I’m not familiar with the paper you’ve quoted above. Could you please elaborate a bit more on what you are trying to model here? Maybe a drawing or a lens file can help. 

Best,

Hui

Reply


Community Posting GuidelinesCookie settings


Zemax Community

Need more help?

To Chinese users:

Do not provide any information or data that is restricted by applicable law, including by the People’s Republic of China’s Cybersecurity and Data Security Laws ( e.g., Important Data, National Core Data, etc.).


不要提供任何受适用法律，包括中华人民共和国的网络安全和数据安全法限制的信息或数据（如重要数据、国家核心数据等）。



Privacy policy   License Agreements    Terms of use    Cookie Policy   Zemax Account Licensing Policies