People & Pointers
Use this space to show off your skills, introduce yourself, or to chat about the latest in the world of optics.
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Zemax and Edmund Optics Certification
What a course by Zemax, LLC and Edmund Optics that will teach you how to:* Define the basic properties of light and how it interacts with other objects* Interpret simple ray diagrams*Define optical system requirements and describe how they affect system performance*Identify factors limiting optical performance*State the optical aberrations and their effects on real systems*List sources of error in manufacturing and assembly and describe how they can affect system performanceCertificationLinkedin post!
Tech Tip Tuesday: STAR with Mobile Phones and Mobile LiDAR
When designing cell phones and mobile LiDAR applications, or really any system with motion, vibration and shock can be a concern. One technique used by both cell phone and aero-space applications is to use step mounts on the optical elements to keep their motion more ridged. The issue with designing this type of step and testing the effects of FEA are how to integrate the optic with the step.Today’s Tuesday Tech Tip is how to create a step mount and run a STOP analysis on the system. Creating these steps in a CAD platform and making the distance between the lens and the step a nominal size is the first step. Using a CAD tool that allows optical properties and ray tracing such as OpticsBuilder or Speos will help with this process. Next the FEA software needs to allow this nominal distance to be perceived as ideal for transferring forces and thermal effects. This will allow both thermal and structural data to run on the new combined optic of the lens and step as though it were a monolith
Any difference between FCGS,FCGT and the field curvature& distortion analysis plot
Generally speaking the FCGS and FCGT values are more robust compared with the analysis window.It's mentioned in The Analyze Tab (sequential ui mode) > Image Quality Group > Aberrations (Image Quality Group) > Field Curvature and Distortion :Strictly speaking, the field curvature and distortion plots are only valid for rotationally symmetric systems with plane object and image surfaces. However, OpticStudio uses a generalization of the field curvature and distortion concepts to give reasonable results for some, but not all, non-rotationally symmetric systems. Caution should be used when interpreting these data for non-rotationally symmetric systems or systems with object and/or image surfaces that are not planes.FCGS and FCGT have more reasonable results for non-rotationally symmetric systems.If the system is rotationally symmetric, the Field curvature values reported by the FCGT and FCGS operands should match those values listed in the Field Curv/Distortion plot, for the same
Modeling DOE Pattern/Image Generation using POP
This is a brief description of my recent experience using POP to model diffractive optical elements that may be of some interest to other users.It is well-known that Diffractive Optical Element (DOE) technology can be used to generate custom intensity patterns or images based on coherent optics. For example, illumination of properly constructed phase elements (i.e., DOEs) by a coherent laser beam can produce interesting intensity patterns in the far field. Anyone who has walked the exhibit hall at Photonics West has surely seen examples of this. Various techniques can be employed to design a DOE, with the Iterative Fourier Transform Algorithm being one popular scheme (see, e.g., F. Wyrowski and O. Bryngdahl, “Iterative Fourier-Transform algorithm applied to computer holography,” JOSA-A 1988).Here is a brief description taken from the Holoeye website: Modeling DOEs in OpticStudio is possible by using Physical Optics Propagation (POP). One can envision two possible approaches: (1) mo
Tech Tip Tuesday: Machine Vision 2-D & 3-D Imaging Using FEA & STAR
As humans become more reliant on technology, machine vision becomes an increasingly critical component. Many systems today rely on machine vision systems, including package tracking, security scanners, autonomous vehicles, and even some smart phone applications. As with many optical systems, these machine vision cameras can be subject to environmental conditions. To illustrate this, we look at a single example of an automotive HUD system that has an Inferred camera to enhance the machine or drivers’ perception of animals and pedestrians. The image glow demonstrates how the image captured by the camera can be affected by extreme thermal loads which could be placed on the system during a drive on a hot summer day. This could pose a problem, as the system may not correctly identify a hazard, potentially resulting in human injury. To tackle this challenge, optical designers and engineers undertake a process known structural thermal optical performance (STOP) analysis. Consider how a tempe
Example of a Thermal Index Data file (*.TID)
I have attached an example of a TID file. This file contains the index of refraction at multiple temperatures and wavelengths. The first line contains the word PRESSURE followed by the ambient air pressure in atmospheres.Then the data consists of 3 columns: temperature, wavelength, and index.The temperature of the first data point defines the reference temperature for the glass.It can then be fitted with the Glass Fitting tool.Once you run the tool, you will get a report and this can be automatically added to a catalog.
Shop specifications for Mangin mirror?
Could anyone share a successful specification sheet example for a Mangin mirror to go out for quote? I have the toleranced radii and center thickness, edged diameter and clear apertures all defined, calling out wedge across clear aperture to be less than 25µm, polish quality, AR coating on the refractive surface, etc. all complete. What I don’t know is how best to specify the reflective surface. I know the desired reflectivity, which will likely either require aluminum or silver, but I’m not familiar with how to specify the protective coat(s) that is/are applied on top of the reflective coating. Is flat black epoxy paint OK, or can it oxidize the coating and cause delamination? Does an intermediary non-oxidizing, adherent coating need to be applied over the reflective metal before painting flat black? Thanks for any advice. Mike
About the rotation radius of Toroidal surface
The definition of Toroidal surface is mentioned here:The Setup Tab > Editors Group (Setup Tab) > Lens Data Editor > Sequential Surfaces (lens data editor) > ToroidalToroidal surfaces are formed by defining a curve in the Y-Z plane, and then rotating this curve about an axis parallel to the Y axis and intersecting the Z axis. Toroids are defined using a base radius of curvature in the Y-Z plane, as well as a conic constant and polynomial aspheric coefficients. Another way to verify, we can use the surface sag, the rotation R’s value is 0：This is a trick to test some unfamiliar surface, we can use Surface sag and surface sag cross to test.
Optimize your mixed mode system
Hello!I recently came across an interesting question regarding optimization in mixed mode which I would like to share here. Feel free to put any potential follow-up questions into the comments.How to model a mixed sequential/non-sequential system – Knowledgebase (zemax.com)Let's take a simple mixed mode system with a tilted Standard Lens Object which focus the rays onto an image plane. As you can see on the image below, we have two variable parameters in the whole system:Tilt About Y, Non-sequential Parameter Thickness Surface 3, Sequential ParameterIf we now optimize with the Merit Function default settings (Wizard Default settings) to minimize the Spot Size, we can observe that both the sequential and the non-sequential variables are optimized: Have a good day!
Export CAD files - Origin of Coordinate System
Hello there,Let's say we have a very simple singlet system with two collimated fields which are focused onto an image plane. We now like to export this optical system, as a STEP format, from OpticStudio into our CAD environment. We can do so with the Export CAD File tool which can be found in the File tab of OpticStudio. Once the optical system is opened up in CAD (Here Ansys SpaceClaim) it looks like that:As visible on the image of the exported Singlet above, the origin of the global coordinate system within the CAD environment is set at the beginning of the rays. This is because the first Surface was set as the Global Coordinate Reference in the Surface Properties of OpticStudio. To change the coordinate system origin point of the exported cad file, another surface can be set to be the Global Coordinate Reference surface.Taking this Singlet as show case example, it can be observed that the origin of the global coordinate system has shifted from the beginning of the rays to the front
Tech Tip Tuesday Cell Phone Design 10-18-2022
Tech Tip Tuesday Cell Phone Design 10-18-2022 There was a time when a phone was used to make calls, now it keeps track of our appointments, allows us to shop from virtually anywhere, read emails, and watch pointless cat videos. The one feature most people rave about when it comes to phones though is oddly not the phone part at all, it is the camera most people are concerned about. Given the amount of real estate cell phone makers dedicate to their cameras, and the amount of resources that go into developing them, the major brands are also concerned about cameras. This brings optics to the forefront and a cell phone has a lot of unique design challenges. We have high expectations of our phones, after all we carry them everywhere. They need to perform in all weather conditions, every type of lighting and not be damaged from shock, vibration or general carelessness. A tall order for any product, but to do all that and stay within the tolerances needed for an optical system, it is a very t
Global design of an off-the-shelf objective lens with no a priori design and macro-enabled optimization
My article on global lens design and using commercial off-the-shelf lenses was recently published. This was my “swan song” before taking my current position. Here is a link to the article. There are resources included for the ZPL code. Hope you enjoy.https://doi.org/10.1117/1.OE.61.10.105104AbstractSynthesis of original optical designs is a challenging endeavor for novice lens designers. It is made more difficult when attempting to design a compound lens from off-the-shelf lenses. All but the simplest compound lenses resist ready analysis or understanding from a first-principles approach of geometric optics; however, many optical design packages include powerful optimization algorithms for both local and global searches. Despite the power of these tools, the initial construction of a starting lens and merit function remains crucial to the effective utilization of the optimizer. A workflow is presented for a generic starting design, construction of the merit function, and the optimizati
Zemax - Lumerical RCWA dynamic linking updates & known bugs
OverviewThis post is a place for this feature: Dynamic workflow between Lumerical RCWA and Zemax OpticStudioThe main purposes are mainly the following 2.Maintaining a list of improvements & bugfixes history. Users can easily check when and what problems are solved and what improvements were made. Gathering feedbacks or a place for users to discuss.:)Useful ResourcesDynamic workflow between Lumerical RCWA and Zemax OpticStudio Exit Pupil Expander with 1D-2D Gratings RCWA Solver - Simulation Object RCWA Solver Introduction Known bugsMax Order X/Y cannot be negativeCurrently if the Max Order X/Y are negative, the k vector domain in Lumerical RCWA is not correctly set by the dynamic link. This will be fixed in lumerical-sub-wavelength-dynamic-link-2023R1-3.dllVersion of Ansys Common LicenseThis is not a bug of dynamic link but will affect dynamic link users. There is a workaround as described below.A rule of thumb is, when using the dynamic link, Lumerical must be opened earlier than O
How to model a Faraday rotator/ isolator
Faraday rotators are polarization rotators. The state of polarization (such as the axis of linear polarization or the orientation of elliptical polarization) is rotated as the wave traverses the device (link). The tricky thing when modeling Faraday rotators is the apparent non-reciprocal optical propagation. The ray back through the rotator does not undo the rotation of the first pass, but instead adds to it. This can be modelled with Jones Matrices and the Consider Objects type rule, so that light going one way sees one JM, and light going the other sees the other. I have set up an example attached that shows how it can be done (seq and non seq).In non-sequential, the optical set-up is like this: Source Ray --> Jones Matrix (Forward and Backward) --> Rectangle (MIRROR)The source only considers the Forward Jones Matrix when sending light. When light is reflected on the rectangle, the Rectangle only consider the backward Jones Matrix. This can be checked in the Ray Database View
Updated Export to Speos Lens System in 22.3
Have you wondered how your optical system designed in OpticStudio will behave in the real 3D world? Ansys Speos can take your OpticStudio model and fully simulate your system in a 3D environment, including some environmental challenges such as rain and fog. But we all know that modeling an entire optical system in a complete 3D digital environment can be computationally costly. To reduce modeling expenditure for preliminary studies, we are introducing the Export to Speos Lens System (SLS) in OpticStudio 22.3.The SLS is a reduced-order model of your optical system based on a camera obscura model where the exported optical system acts as an optical transfer function. Therefore, the SLS does not carry all the information for complete modeling of the imaging capabilities. Still, it can provide valuable insights early in the design process, such as perceived image quality and irradiance models. The SLS can deliver these results within less than five minutes saving time during preliminary an
ROC (radius of curvature) can be divided in half on the parabolic mirror between the add-on and base composite surfaces, but not Spherical surface
Hi Zemax community, a question regarding why ROC (radius of curvature) can be divided in half on the parabolic mirror between the add-on and base composite surfaces while keeping the perfect focus, but not the same case for the spherical surface type, is often asked. Here we will give an on-axis mirror example to demonstrate the math correlation behind this concept. First, let’s start with an on-axis spherical mirror (Example file: 1_SphericalMirror.ZAR): In this example, the incident rays originating from the center of sphere curvature are reflected by the spherical mirror surface, back along the original way. The radius of curvature and back focal length is -100mm. No optical aberration is introduced in this example, the spot diameter will be perfect. Fig 1. Spherical mirror layout Now let’s make a comparative file with an add-on composite surface at the front of the base spherical surface (Example file: 2_SphericalMirror_WithAddOnComposite.ZAR). To main the same EFL as the first
Tech Tip Tuesday Multi-Physics
Tech Tip Tuesday 7-12-22 Multi-Physics ApplicationWith the right combination of the Ansys software suite including, OpticStudio and STAR. It is possible to integrate optics with other physics, such as finite element analysis (FEA), computational fluid dynamics (CFD), particulate motion, thermal analysis, optimization tools, and more. Below is an example of a multi-physics workflow for a high power laser. Similar workflows are possible for many applications. In addition to having in depth analysis of all the physics involved with tools such as Fluent, Mechanical and WorkBench, it is possible to export the FEA and CFD data in a way that OpticStudio can use to continue the optical design.After running the your studies including structural, thermal and CFD, bring it full circle to OpticStudio via the STAR module. To do this as effortlessly as possible, try our ACT file extension for Ansys Mechanical, it allows the data to be exported in a format STAR will recognize with minimal work from
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