I am using the ZOS-API in C# with 4.8.1 framework using Zemax OpticStudio 2024 R1.02 and getting an error message when running the Local Optimization tool.The error message returned from running the tool is “Input settings are invalid”.This occurs only when I load from an Archive File (.ZAR).   If I load from a model file (.ZMX) then the Local Optimization tool works as expected.For the fields that I set, there are only 2; Algorithm = DampedLeastSquares and Cycles = AutomaticIt’s weird and I can’t understand the difference between accessing the model from an Archive would create this issue. NOTE, that I did load the ZAR file from the actual Zemax application and Optimization worked fine. If anyone has any ideas as to the issue then please let me know ThanksB.

Hello. I am trying to model a Angle Cleaved fiber source that emits beam. I would like to show the exit beam is offset at 4° from the optical fiber mechanical axis. How can I model this in SEQ mode?  Essentially, I want to model something like shown below in Zemax Sequential mode.PS: I am referencing this KB article to model a Angle Cleaved fiber on the receiving side. 

Hello, I am currently trying to replicate some of the previous chats that say you can rotate multiple objects around a common object in the NSCE.  Aligned cylinders (see image above) I currently have a small ellipse as my object  I want the two cylinders to rotate around. The first cylinder has one edge right where the ellipse is and it extends 90mm. Then I wish to start a new cylinder that is smaller in diameter from the end of the first cylinder. This new cylinder extends 50mm. I wish to have both rotate around the ellipse that I have. That is when I rotate the ellipse, the two cylinders rotate and stay centrally aligned to one another. Currently when I try to do the pickup method, I get this result (see image below). The second cylinder rotates 5 degrees, but does not stay aligned with the end of the bigger cylinder. I am not sure how to fix this? I have tried doing pickup on several variables and am not getting any luck. Any and all help would be greatly appreciated! Thanks! 

Hello fellow optics enthusiasts,I’m currently working on a task where I need to ignore multiple surfaces in a Zemax optical system using the ZOS-API. At the moment, I’m using the following loop:for i in range(150, 160): surface = TheSystem.LDE.GetSurfaceAt(i) surface.TypeData.IgnoreSurface = TrueHowever, this approach seems to be quite slow. Has anyone found a more efficient way to ignore multiple surfaces at once?Any insights or suggestions would be greatly appreciated!Thanks in advance,Sebastián

Is there a way to access the properties of a coating in the ZOS-API? The article below shows how to access the name of the coating, but does not show how to get the properties of the coating.I’m not finding any handles that give the actual coating information. Thanks!

Hi everyone!I'm working with an optical system that operates using a single field (an on-axis collimated beam - object at infinity), and I’d like to estimate its distortion.As I understand it, distortion is typically evaluated by comparing multiple fields, so I would need to add additional ones to get a result. However, I’m wondering if there’s a way to estimate distortion using only one field.I've attached a layout screenshot showing the image space of the system. Is it possible, for example, to infer distortion by analyzing the standard deviation of distances D1, D2, D3, D4, etc.? Presumably, if distortion were zero, these distances would all be equal (I already developed that metric in Non-Sequential raytraces with the API). I realize this is limited to a single axis, but switching to Non-Sequential mode isn't an option in this case, as the system includes a black box component.Any insights would be greatly appreciated.Thank you! 

I am unable to set the source sampling in NSC; here is my code: led_source = TheNCE.GetObjectAt(1)led_source_type = led_source.GetObjectTypeSettings(ZOSAPI.Editors.NCE.ObjectType.SourceRadial)led_source.ChangeType(led_source_type) led_source.SourcesData.PrePropagation = -1print("Preprop: ", led_source.SourcesData.PrePropagation)print("Sampling: ", led_source.SourcesData.SamplingMethod)led_source.SourcesData.SamplingMethod = "Sobol"print("Sampling: ", led_source.SourcesData.SamplingMethod) Note Pre-propagation can be [set, get] through SourceData, whereas SamplingMethod can only be [get]. When I execute this code I get the following: Preprop:  -1.0Sampling:  SobolTraceback (most recent call last):  File "C:\Users\matthew.haines\Documents\Zemax\ZOS-API Projects\PythonStandaloneApplication4\PythonStandaloneApplication4\PythonStandaloneApplication4.py", line 226, in <module>    led_source.SourcesData.SamplingMethod = "Sobol"TypeError: since Python.NET 3.0 int can not be converted to

My codes (that were working with the 2024 version) do not work anymore with the 2025 release.this is the error I get in the function “InitConnection()”:Message: Could not load file or assembly 'ZemaxEngine.dll' or one of its dependencies. The dynamic link library (DLL) initialization routine failed. (Exception from HRESULT: 0x8007045A)Source: mscorlibHelpLink: None

Hi all,I'm using the ZOS-API in Python (OpticStudio 2024 R1) with IBatchRayTrace to trace manually defined NSC rays. I'm creating the interface using teh batch tool and adding rays using nscData.AddRay(...).The trace completes successfully (batchTool.Succeeded is True, and RunAndWaitForCompletion() doesn't crash ). However, when I read the results using nscData.ReadNextResult(), the numSegments output parameter is consistently 0 for all rays. This happens even when:The system is minimal (new file, 1 wavelength, 1 Standard Lens, 1 Detector Rectangle). Rays are defined with various trace options (None, UsePolarization, UseSplitting, UseScattering, and combinations). The ray path clearly interacts with objects (e.g., passes through the lens and hits the detector).It also doesnt show any errors...Is it expected that IRayTraceNSCData.ReadNextResult will return numSegments = 0 for simple interactions like refraction or absorption when rays are launched via AddRay? If so, what is the intended

Hello,We are urgently looking for an alternative to ZPL-GETZERNIKE using ZOS-API.The point is that we cannot tell “TheSystem.MFE.GetOperandValue(MeritOperandType_ZERN, “ the maximum term of Zernike.“TheSystem.MFE.GetOperandValue(MeritOperandType_ZERN, “ always develops only up to the given coefficient :-(MAny ThanksHans-Jürgen

Hi,This is Oliver. I’m currently working on an optical fiber endoscope project, where minimizing back reflections is critical for our application in optical coherence tomography (OCT).In particular, I’m looking to quantify the back reflections from specific lens surfaces—such as the ball lens-air interface highlighted in the attached figure. The system involves a single-mode fiber launching light through a segment of coreless fiber and a ball lens. The majority of the back reflections appear to originate from the ball lens-air interface.My goal is to use Zemax to estimate the amount of power reflected back into the single-mode fiber. For example, if the input power is 10 mW, is it possible to calculate the power reflected back toward the source in Zemax?Ultimately, I plan to optimize the material and geometry of the ball lens to minimize these reflections. I’ve attached the Zemax file for your reference, and I would appreciate any guidance or suggestions on how best to approach this an

Hello, so far I was under the impression that the EFLY/EFLX operands ignore all Zernike coefficients (e.g. of Biconic Zernike surface) and purely consider the radii of curvature . Now I discovered that the coefficient “Zernike 4” and its effect on the curvature is considered for EFL calculation. Although the Zernike 4 polynomial is proportional to r² and thus directly changes the effective radius of curvature, it is by far the not the only Zernike polynomial effecting the EFL in X- and Y-direction (e.g. Zernikes 5, 6, 11, 12, 13, ...).  Is this change in EFL calculation a bug or intented? What was the OpticStudio release this change in ELFY/EFLX was introduced with? I could not find any mentions in the release notes.  Best regards, Simon

Hello,I am facing an issue in image simulation for my designed IR system which is showing a circular ring like patch. I am not sure whether this is an image simulation issue or there is some actual error in the system which is being reflected in the image simulation.The design also includes binary surfaces for chromatic aberration correction.Attached is the image simulation result.Any help is highly appreciated.Regards,Supravat.

hi,I would like to know how to report the angular coordinates of the chief ray relative to the vertex of a surface.specifically, i would like to report (or know the operand) of the angular X and Y coordinates ( the X and Y in the upper left of the image below).  

Hello. Is there a setting in Ansys OS 25 release to set hide/unhide the GUI Ribbon? I prefer to use maximum screen area if possible.The only way I think is to double-click the tab to hide/unhide.-Asuku

It appears that there is a known ZOS-API initialization error when using OpticStudio 2025 R1.  Here’s what is stated in the 2025 R1 release notes: I’m currently using OpticStudio 2025 R1.01 and encountering this problem with Matlab R2021a (which previously worked fine with OpticStudio versions prior to 2025).Does anyone know if updating to the latest Matlab release will solve the problem?  If not, I wonder how/when this bug will be resolved?Thanks,Jeff

I would like to model a fiber source array with a X° facet angle in sequential model -  I would like to control the number of rows and columns by defining a pitch size in both axis.An example or article that shows how this can be achieved will be helpful? PS: I see that this is possible w/ a non-sequential setup (How to create an array of sources – Knowledgebase) but is there a way to do this in sequential?

I have built a sequential model where I am trying to simulate how to edge-couple a 780nm laser diode to a thin-film lithium niobate waveguide (PPLN). I am using POP to calculate the coupling efficiency and have acquired a .zbf file from Lumerical that is the ‘output mode’ of the PPLN when running in the SHG mode, and using this as the ‘input’ data for the fibre overlap integral data. I believe I am getting reasonable answers but the beam profile graph is not showing the beam profile I would expect. The x and y half-angle divergences (in degrees) of the laser is 4.25 and 8.5, respectively. The beam profile at a distance of 15 microns from the laser shows a beam that is bigger in x than in y but only in the POP graph. in the 3D shaded model it is larger in y than in x, as I would expect from a DBR type laser. Can someone help me make sense of this?  The Rayleigh range of this beam is xR ~ 45 microns and yR ~ 11 microns, is the fact that I am looking at distances on the order the Rayleigh

I’m using the ZOS-API (ver. 2024 R1) with C# and creating an Open3DViewerExport (I3DViewerExport) bitmap of the Ray Trace.The bitmap gets generated to a file but includes the axis (X,Y,Z) in the lower left corner of the image.The application allows to turn this access off but I don’t see the option within the API. Is there anyway that the API can turn this off as well?Thanks.B.

Hi All,I'm working in Non-Sequential Mode and using a Cylinder Volume  as a parent object to create an array using Array Ring.I want to clarify: When I create an array using the parent object, do rays still interact with the original parent object as well as the array instances? If I only want rays to interact with the array elements (and not the original parent), what is the correct way to set this up? Should I disable drawing or use the "Ignore Rays" setting on the parent object? Any guidance or official documentation links would be really helpful. Thanks in advance!

/

Hello everyone,I have an optical design with an effective focal length of 250 mm. However, after adding a Schmidt prism, the effective focal length becomes -0.106 mm, whereas it should be around -205 mm. Could you please help me with this issue?

Hello! I’m trying to run batch ray traces from Python and have encountered some difficulties. Originally I didn’t use this feature because it was quite slow - since each ray needed to be traced individually in a for loop. But after discovering this Knowledgebase article: Batch Processing of Ray Trace Data using ZOS-API in MATLAB or Python – Knowledgebase (zemax.com) I got excited to try the new Raytrace DLL.|I started by getting the MATLAB example file working, which was pretty trivial. It basically ran as soon as I downloaded it. However, I need the raytracing to be done in Python - so I tried to translate from the MATLAB example file, which did not work very well. First I encountered this error:module ‘clr’ has no attribute ‘AddReference’Which I fixed by uninstalling clr and installing pythonnet (woops, that’s on me). I had to downgrade to Python3.8 to install pythonnet. The next error I encountered after I finally got the code running seems more fundamental, when trying to run NET.a

For an Even Asphere surface:the tilt tolerance is represented by the TETX/TETY operands with Surf1 and Surf2 pointing to the same surface number. the centering tolerance is represented by the TEDX/TEDY operands with Surf1 and Surf2 pointing to the same surface number.The TETX/TETY values are correctly written in “sigma” place of the 4/ sigma (L) indication of the drawing.On the contrary, TEDX/TEDY values are not written in “L” place of the 4/ sigma (L) indication in the drawing.Why? Is the only solution to compile the “L” value in the drawing manually?Thank you

My codes (that were working with the 2024 version) do not work anymore with the 2025 release.This is the error I get:Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'ZemaxEngine.dll' or one of its dependencies. A dynamic link library (DLL) initialization routine failed. (Exception from HRESULT: 0x8007045A).