Got a question?
Can't find the answer you need? Ask your peers!
- 2,110 Topics
- 5,852 Replies
Tolerance script - saving Monte Carlo tolerance values for use in several optimizations
I am trying to use tolerance scripts to realistically model my lab’s compensation procedure. The system consists of several lenses mounted in two lens barrels that fit together. If the performance of the system is not compliant, then one of the barrels is rotated 90º with respect to the other and the performance is checked again; subsequently it can be rotated 180º or 270º as needed. I am thinking to model this by using multi-configuration for each of the barrel rotation options (0º, 90º, 180º, 270º), but as the system is nominally rotationally symmetric, this by itself will not do anything. I want to know how to apply the rotation AFTER the tolerance values (on lens wedge, tilt, shift, etc.) are selected for each Monte Carlo trial, so that I can rotate the directional tolerances for the lenses in the first barrel with respect to the tolerances for the lenses in the second barrel. For example, if a lens in barrel #1 has a tilt of 0.062º +X in a Monte Carlo trial, I want to compare this
How to set max cores by default for ray trace in NSC
Hi dears,I would like to know how to set the maximum number of cores for the ray trace in NSC. My workstation has 32 cores, but to be able to work with other applications during the calculation I considered it sufficient to launch the ray trace using a maximum of 25 cores, unfortunately at the first launch of the calculation the SW sets the maximum number of cores available and if I forget to change this value I have to stop the simulation and change it.Thanks a lot to everyone.
Hi,I was reading Shawn Gay’s excellent article on the geometry used by the various curvature calculations. In it, Shawn writes:In the Surface Curvature analysis, the convention that OpticStudio adopts is to align the tangential direction with the x-direction at the surface vertex.This statement is true and of course the choice is arbitrary, but it seems to me this convention is 90 degrees at odds with where we use the term tangential elsewhere. The surface curvature data is independent of ray tracing, but when doing raytracing the convention OS uses is that tangential is along the y-axis.I must admit I assumed that this was the case in the curvature plots. I read the documentation, and it’s not described there. I searched for a KB article instead and found what I needed to correct my understanding. But since the convention is arbitrary, did we have to use a convention that is orthogonal to the convention used elsewhere?This is an old feature and I know that changing the convention will
How to limit the relation between thickness and radius to make sure the lens is realistic
HiI want to check how should we limit the diameter-to-radius ratio in Zemax? I’m using MNCG and MXCG to limit the thickness of the lens. However, during the optimization process, the lens radius can be negative and the absolute value is larger than the lens thickness which make these lens not real. Could we use some operand to avoid the situation? I’m trying to find the operand to get the radius and limit the thickness according to the radius but failed to find the operand. Do we have other operand to do that?Thanks！
model a lens optical aberration with Zernike coefficients
Dear all, How to model a black-box optical system using Zernike coefficients – Knowledgebase (zemax.com) tells us how to model a lens optical aberration using Zernike coefficients. However , this method can only define the aberration in one field at one wavelength, in most cases it’s not sufficent to define a lens overall aberration. any further suggestions? (I’m working on the measurement of infinity corrected objectives with Shack-Hartmann sensor and i want to reconstruct the aberration in a simplified model.)
Trick: Alternative Use of TOLR - how to add an optimized parameter as an operand to the Merit Function Editor
TOLR is an MF operand that returns statistical results for tolerancing sensitivity analysis, and adds these results to the optimization process. In the background, the tolerancing analysis with the compensation consideration is another optimization process under different perturbation conditions. Therefore, TOLR can also be used as an optimization operand for the parameters that require optimization beforehand. Concept of using TOLR This section discusses the use of TOLR, which is unrelated to tolerancing. Instead, it utilizes the optimization process behind what we see. To use TOLR, you need to use a tolerancing user script. This is because the merit function used in the previous optimization and the main optimization process are different. By using a tolerancing user script, you can control which merit criteria to use tolerancing user script defines how to compensate and optimize. The following commands are the ones we used: CLEARCOMP (remove variables), COMP (set variables), LOADMER
Image simulation - Mixed mode or Multiconfiguration
Hello, I am currently working on a telescope whose primary and secondary mirrors are divided into three segments. I would like to see how deviations in their position relative to each other affect the final image. Does anyone know what mode (Sequential and multiconfigurations or NSQ) is best to use for this analysis?Thanks in advance for your help.
Intro to Lens Design ZEMAX - Transmission Sphere Design Question
Hello ZEMAX community, I am currently practicing the Lens Splitting based on the <Introduction to Lens Design in ZEMAX> Chapter 9. The problem is to design a transmission sphere as described in below. I got the spot diagram to be close to the Airy disk, but not exactly smaller. My struggle is that I could not understand/use notes (d).My question is in the notes (d) provided. It says the condition for the transmission sphere is BFL = EFFL and use the Operands OPTH and DIFF. Here, I understand that the OPTH calculates the optical path based on a selected surface. But I could not think how to use two OPTHs to make it work.Alternatively, I searched that the critical design condition for the last surface is that its radius of curvature needs to be equal to the BFL. To me, to equate the radius of the last surface (6th) = BFL (TTHI operand), and use DIFF to optimize the difference is zero makes more sense. Can anyone please comment on the question or verify if my thoughts are right?Than
What are the Optic Studio Constraints of Modelling Bulk Scattering through thick diffusive Media?
Hi, I want to measure the time of flight from rays scattered from thick diffusive media, e.g. a 5cm thick block of foam, resin, human tissue, e.g. 30-100 Transport Mean Free Paths, but I am finding hard limitations with the OS settings (see attached files).As a general example, using the volume physics dialogue box, DLL defined H-G_bulk: using mu_s = 11.5 mm-1, mu_a = 0.0016 mm-1 and g=0.87, Mean Path=0.09 mm and T = 0.99.Setting intersections to max: 4000, and segment number to 100k, with Min Rel Intensity (min) 1E-36 (to collect everything as rays can lose many orders of magnitude). This arrangement flags the “Error: Not Enough Intersections Allocated to Finish Ray Trace” for several cm of diffusive media, and indeed if I ignore this, a histogram of #segments shows it is clipped at 4000 (see ZMX and pngs attached). For context I measure the OPL of a ray by using the ray coordinates as vectors (* refractive index) per segment and summing. Splitting is turned OFF because the ZRD lists
MWIR coating transmits over 100% . . . what's going on?
I have a MWIR coating on a germanium substrate (with internal transmittance set to 1.0) and I’m getting double-sided transmission greater than 1.0. How is this possible? This result disagrees with Code V, Filmstar and Essential Macleod. Even if I vary the layer thicknesses by 3%, transmission still can exceed 1.0 at angles of incidence less than or equal to 20 degrees.
Simulating Opal Diffusing Glass - Diffuser
I’m interested in using non-sequential environment to simulate this Opal Glass diffuser from Edmund Optics: https://www.edmundoptics.com/f/broadband-hybrid-diffusers/34772/It’s a bulk scattering substrate with grit 120 surface on both sides for improved NIR wavelength scatter since the bulk is optimized for visible wavelength scatter.I’m quite unfamiliar with how to go about it and through searches on google and here didn’t find anything similar that I could replicate.An example project of the hybrid diffuser would be extremely helpful.Manufacturer doesn’t provide ZEMAX files for this.I don’t know what bulk material to use. N-BK7? Something else? Which bulk scattering method to use? Any guesses on the parameters for that method that would be reasonable? How do I simulate ~30% transmission of this type of diffuser, presumably the rest of the light is backscattered or absorbed, not sure how much of either happens?Thank you
Why is ZEMAX drawing the mirror substrate on the wrong side for a user-defined aperture?
I’m working on a model for galvanometer mirrors that have a polygonal shape. For the mirror surface, when I set the aperture to the user-defined file (X,Y points clockwise, without a redundant endpoint), and draw the surface as a flat substrate with some thickness, the rays appear to travel through the substrate and reflect on the other side. I would like the mirror to be on the side that the rays see first. Is there a way to change that?
PSF from MTF
Hi Community,Someone recently asked how “easy” it would be to recreate a PSF from a given setup of MTF measurements. My first answer was “don’t do that” but I’m trying to quantify all the issues that are present with trying to recreate the PSF. Below are the major hurdles I see but I would love to get other people’s feedback into the feasibility/pitfalls that need to be considered:A single scan MTF is essentially a FFT of a 1D cross-section of the PSF. If there is no rotation in the system, then the MTF is the FFT of the Y axis (tangential) and X axis (sagittal); there is no information about any data points that lay off the x/y local axis. To fully recreate the PSF, you would need to have multiple MTF scans at different angles. The MTF is actually the absolute value of the OTF, so the MTF only has real values in it. The FFT/IFFT for any real-valued signal is always symmetric, so an asymmetric PSF cross-section can not be reproduced from the IFFT of the MTF, at least not without (
MTF measurement / Correlating experiment to model
My MTF measurements don’t match my WFE and PSF measurements. I’m trying to use a model to figure out why this is the case so I can improve the MTF measurement.I suspect the reason for the discrepancy is that the radiance from the MTF target does not fill the pupil in the same way that the WFE and PSF measurements fill the pupil. However, I cannot figure out a way to verify this assumption with a model in OpticStudio.The MTF test setup is a trans-illuminated reticle (not an epi-illuminated printed target). While it is possible to use apodization in an OpticStudio model, this is not the same as a trans-illuminated reticle where a condenser lens may be used to focus light onto the reticle.Can anyone suggest a method of modeling this in OpticStudio in a manner that captures the effects in a nearly diffraction limited system?ReferencesISO 12233 Website detailing MTF test targets (link) Tutorial on Slanted Knife edge test (link) Example of a trans-illuminated target in a collimator (link)
How to find the patent of exact objective lenses part number
Hi,Is it possible to find a patent of the exact objective model based on the part number available on the manufacturer’s website? If I find the patent of the objective with the same main parameters ( like NA or magnification) how do I know that this is the exact model I am using?Regards,Marzanna
Reconstruction of objective lenses from the patent
Hi,I am learning how to reconstruct the objective from the patent. I tried with https://patentimages.storage.googleapis.com/f4/46/e9/67ad0174b44df7/US6501603.pdf Embodiment 3, which looks like this My modulation looks like thisthe arrows represent errors ( in my opinion) although the thickness between those surfaces is correct with the design specification, I wonder why this happened. I changed the thickness values ( surface 16 and 24) it looks better but it is not the correct value according to the patent.How much more I can do with this reconstruction to make sure it is as close as possible to the original specification of the patent? My dilemma is that if I apply a merit function and do optimization, it may change the radius and thickness of the surfaces hence the simulation won’t show the real objective performance. Regards,Marzanna
Dear Community,I am working on the design of an off-axis parabola (OAP), the purpose of OPA is to collimate the light coming in the form of the cone from a laser diode to 10 mm beam width. At the first try I did the design by setting the entrance pupil dia 10 mm and focuses it by using an OAP for a particular F# (so that I can get the laser cone angle in OAP image space). 2nd try I did in the opposite way, defining the source as an "object cone angle" and decentering it by changing VDX value in field data editor, for collimation I am using the same OAP. By doing this collimation is achieved but beam width is not same as previous design beam width i.e. 10 mm.Where I am missing?Zemax design files are attached for reference.Thank You.
Coordinate system for skew gaussian beam propagation
Hello,I have a question regarding skew gaussian beam propagation mode:A simple astigmatic gaussian beam can be described by two separate caustic hyperbolas.These two hyperbolas belong to two perpendicular planes (e.g. xz-plane and yz-plane, z:propagation direction).The x and y-axis are parallel to the principal axes of the elliptical intensity profile of this beam.Now let’s assume that we have a spherical convex mirror. The simple astigmatic beam hits this mirror in an arbitrary point on the spherical curved surface. Now let’s assume that the coordinate system of the beam (defined by the principal axis of its elliptical intensity profile) is not parallel to the sagittal and the tangential plane of this reflection scenario.Which physical model does Zemax use to simulate such a scenario?How can I get the information about the orientation of the new principal axis coordinate system of the intensity profile after reflection? I did not find any formulas in the help manual…Does the physical
Modelling Human Eye for Illumination and Imaging
Hello, I am hoping to get some guidance on how to model the human eye for an illumination application. I am using a ring of LED’s to illuminate the eye and using the back reflection and a separate optical path to image it.A Fundus camera with an internal illumination path is the specific design.I downloaded the Eye_NSC file from the knowledge base article and made the Iris and Sclera Inner “mirror” surfaces so I could get a reflection from it.I have empirical data that shows the illumination pattern from a real system that looks like elliptical rings, but I can’t seem to get the same pattern in NSC mode through the optical system. I am focusing on the model eye being incorrect in some way, but I’m having a hard time figuring out how to change the model to suit this application.Is there a better way to model the eye to get reflections from it?
Iso Drawing for Biconic Lens
Dear Ladies and Gentlemen,I have tried to generate a ISO 10110 Drawing for a Biconic Lens.Unfortunately I can only get the conic in y-direction displayed on the drawing,then it says “see attachement”Is there a way to generate a manufactuing drawing for a biconical lens?! Regards, S.E.
Tilting mirrors in Zemax
HelloI am trying to model a scanning mirror actually as in the link below:https://support.zemax.com/hc/en-us/articles/1500005576502-How-to-model-a-scanning-mirrorHowever, I found that when I try to tilt the mirror around y in my case the focus shifts in both x and y directions. The mirror was originally tilted around x by 45 degrees. I then wanted to tilt it around y and that is where I got stuck. In the file you will find 3 configurations for different tilts around y (-5,0,5 degrees). I suspect I am doing something wrong with the coordinate breaks but I have no clue how to solve it. Please advise!
Already have an account? Login
Enter your username or e-mail address. We'll send you an e-mail with instructions to reset your password.