Resources
Supporting Your Metrology and Inspection Solutions
Understanding which metrology system or non-contact measurement method is best suited for your application can be a complex challenge. Our application notes, technical papers, videos, and other resources provide the data and use-case scenarios you need to make an accurate product selection.
To discuss how our measurement solutions and custom engineering services can best serve your project needs, connect with an expert.
- Ophthalmic
- Transparent Armor
- Film Measurement
- Low Coherence Interferometry
Review how interferometry increases quality throughput with non-contact measurement of silicon wafers.
Read MoreAdvanced driver assistance systems (ADAS) increase road safety. Review the distortions and curvatures of six ADAS-capable windshields.
Read MoreLearn how to choose the right light-based metrology tool for your quality control lab.
Read More- Non-contact Measurement of Intraocular Lenses
- CLAS-NX Software
- Wavefront API Software
- Properties of an Intraocular Lens
- Application of Shack-Hartmann Wavefront Sensing Technology to Transmissive Optic Metrology
- Multimodal Characterization of Contact Lenses
- Wavefront Sensors for Control and Process Monitoring in Optics Manufacture
- Non-contact Measurement of a Lens Stack
- Practical Applications in Film and Optics Measurements for Dual Light Source Interferometry
- Application of Shack-Hartmann Wavefront Sensors to Optical System Calibration and Alignment
- Spherical Aberration Standards and Measurement System Stability Over Time
- Historical Development of the Shack-Hartmann Wavefront Sensor
- Measurement of Aberrations in Microlenses Using a Shack-Hartmann Wavefront Sensor
- Shack-Hartmann Sensor Engineered for Commercial Measurement Applications
- Shack-Hartmann Wavefront Sensor Precision and Accuracy
- Testing Highly Aberrated Large Optics with a Shack-Hartmann Wavefront Sensor
- Optical Thickness Measurement of Multilayer Films
- OptiGauge vs. Nuclear Gauge
- Measuring Thickness Uniformity of an Adhesive Deposited on Top of a Porous Substrate
- Materials Cross-Section Using a Low-Coherence Interferometer
- Precision interferometric measurements of refractive index of polymers in air and liquid
Videos
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The OptiGauge is a non-contact, non-destructive, all fiber, thickness measurement interferometer. Protected by over 20 patents and copyrights, the system is designed to:
- Upgrade existing measurement processes
- Improve productivity
- Speed up R&D innovation
- Decrease scrap and associated costs
- Improve quality
- Decrease operator measurement variability
- Meet compliance standards
Lumetrics provides superior service and support for standard and custom solutions.
Refractive index, or more specifically the Group Refractive Index (GRI), is a measure of the optical density of the material. The denser the material optically (higher GRI), the slower is the speed of the light propagating inside that material. The OptiGauge measures the optical thickness, which is equal to the product of the physical thickness times the GRI. The physical thickness is then obtained through a simple table look up. Most plastic and glass materials have a GRI of approximately 1.4 to 1.6. The OptiGauge software uses a default GRI of 1.5.
Lumetrics can also be used to determine material GRI, using a special fixture called the Refractive Index Calculation System (RICS). This simple hardware and software package is inexpensive and easy to use.
The OptiGauge, controller, monitor, and switch all take standard 120 VAC–240 VAC. This is controlled automatically through the power input module
Yes: Although the OptiGauge EMS is sold with a controller, customers are allowed to purchase an OptiGauge II system without the controller if their existing computer meets certain minimum standards. In the OptiGauge II, the customer is provided with the OCC software to load on their computer.
Yes: Customers can load antivirus software on their controller as long as that software does not interfere with OCC functionality. Please consult with Lumetrics software engineering before performing this task.
The light emitted from the OptiGauge is superluminescent LED light centered at 1310 nm. It is classified as Class I laser source, which pose no danger to the human eye. Nevertheless, it is a good safety practice to never stare at the light source (probe output window) directly.
- Clear and translucent materials
- Some opaque materials
- Glass and plastic materials are ideal
- Dry or wet
- Profile of opaque and translucent materials
Contact us by phone or email to discuss your material and whether Lumetrics’ systems can measure it.
- Tubing:Wall Thickness, ID, OD, Concentricity, Ovality
- Contact Lenses: Center Thickness, SAG
- IOL’s: optic zone thickness, haptic thickness
- Films: overall thickness and individual layer thickness
No: As long as some light can penetrate the material, then a measurement can be made. We’ve measured glue on plywood, oil on a drum, food packaging, silicon wafers, and numerous medical devices, coatings, and glass.
Not sure if we can measure it? Give us a call and find out.
No: The OptiGauge does not need to know how many layers there are to measure. It looks for an index of refraction change between layers and displays those as peaks on the screen. The software then measures the distances between these peaks to determine thickness measurements. Custom software is easily written using our OCC Software Tool Kit to provide operator-friendly user interfaces.
This is a question that depends on the situation, but adjacent layers typically need a refractive index difference of 0.01. Variables such as the specific materials, environmental conditions, extrusion variables, and much more can have an impact on this value. Please contact Lumetrics to discuss your specific situation.
Yes: The OptiGauge can measure a surface profile through the use of an internal reference surface. A surface profile can be done at the same time the OptiGauge is measuring the thickness of a sample.
Yes: The OptiGauge can measure wet materials. The OptiGauge can measure both wet and dry materials. Additionally, the OptiGauge can measure solid objects, such as lenses, in a solution.
The OptiGauge displays real-time information both in graphical and numerical forms. An easy-to-interpret waveform provides user feedback for signal strength. This information can also be saved to an Excel-readable format, streamed out an RS-232 or Ethernet port.
- The OptiGauge II measures from 12 microns to 16 mm based on material refractive index
- The OptiGauge LT measures from 12 microns to 5 mm based on material refractive index
- The OptiGauge EMS measures from 12 microns to 50 mm based on material refractive index
Maybe: The thinnest individual layer the OptiGauge can measure is 12 microns (at an index of refraction of 1.5). The OptiGauge can measure a difference in thickness smaller than 12 microns. For example, if the OptiGauge measured a part at 200 microns thick and you applied a 5 micron coating to the part, the OptiGauge could measure 205 microns and then calculate the coating thickness.
Talk to Lumetrics if you have questions on measurement capabilities.
The OptiGauge is calibrated using a NIST-traceable standard. See paper on NIST traceability.
As part of its basic design, the OptiGauge is being continuously calibrated with a 1550 nm laser that is temperature and current regulated. Additionally, Lumetrics provides a verification standard that can be used at any time to verify that the OptiGauge is still measuring within its correct parameters.
Yes: The OptiGauge can be connected to up to eight probes through the use of an optional optical switch.
Switch time from one probe to the next is approximately 100 milliseconds. This includes the signal settling time.
There are many, but there are three main ones: alignment, feedback for adaptive optics, and testing for transmitted wavefront image quality for component quality testing.
You can use wavefront sensors to align each optical element as you put it into the chain, both for traditional lens stacks for multielement optics, or elements in a bench setup (beam splitter, focusing lens, collimating lens, etc.). With Shack-Hartmann for alignment, you don’t need a constant reference leg to balance the set of optics you’re putting together.
The second main use is as feedback for adaptive optics. Any Shack-Hartmann can be paired with an adaptive optics, like a deformable mirror or phase array element (liquid crystal display).
The third major measurement task for wavefront sensors is testing for transmitted wavefront image quality for component quality testing.
There are 2 parts: the Hartmann screen test is just an array of holes in an opaque screen, placed in front of a sensor. When a perfectly collimated beam hits the screens, all dots have the same spacing as holes in the screen. A “perfect” beam is easy to recognize, but as soon as the dots start to move, you have to apply heavy math to determine what is moving the dots around.
The Shack part of "Shack-Hartmann" is that instead of a screen of holes, a screen of lenses is used. With a screen of holes, you lose light, as the dots are only a fraction of usable light. You get all that light back when you use the lenses, so that it can work in lower light. The dots still move in the same manner, and the system automates the ‘heavy math’.
In research, many believe they can make their own Shack-Hartmann sensor. It’s easy until you do it. All the things that can go wrong come up. We’ve spent years figuring it out and building it into a practical, repeatable measurement tool.
Dynamic range and sensitivity—you trade one for the other. The tradeoff between dynamic range and sensitivity is focal length. The shorter the focal length, the more dynamic range, less sensitivity.
A hidden spec that is important is spatial resolution. You always give up a little spatial resolution. As an example, with a high-end interferometer, you get all the pixels. Shack-Hartmann sensors must be composed of a large number of pixels, which limits their spatial resolution.
Our VIS camera sensor covers wavelengths from 320 nm to 1100 nm, while our VIS & IR camera sensor spans 390 nm to 1700 nm.
The most useful features are the refreshing zonal phase map and Zernike polynomial coefficients.
The software also features:
- Selectable analysis wavelength (vis, IR)
- Selectable or automatic analysis aperture and center
- Masking
- Reference file generation for custom setup
The API allows users to create applications including:
- Wavefront profile
- Deviation angles
- Raw and processed images
- Centroid locations
First, identify any aberration limits below which an acceptable optic element or alignment must be used. Then engineer a point in the optics setup where you can monitor the aberrations.
Once set up, near-real-time feedback is available from the wavefront sensor.
In general, flatter is better. Minimizing peak-to-valley (P-V) is often the first parameter an operator can optimize.
Typically, you start by decreasing tip/tilt, and after that, defocus. Then, you may need to decrease higher-order aberration, which often requires fine alignment or design changes.
The most important setup requirement is a good tip/tilt alignment fixture for the sensor. Then, centering fixtures for each alignment element comes next.
Learning the retroreflection technique can go a long way in aiding system alignment.
Having a built-in reference file generation tool makes Lumetrics Wavefront Sensors systems uniquely versatile in the industry.
It is an easy-to-use and customizable sensor, working with our proprietary hardware and software that provides an instantaneous absolute difference, and is ideal for rapid testing of optical stack quality.
Terms & Conditions
We are committed to transparency and reliability in every transaction. Our Terms & Conditions of Sale outline clear policies for pricing, payment, delivery, software licensing, warranty, and support.
We ensure compliance with all applicable laws and provide strong protections for your investment, including confidentiality and intellectual property safeguards. Our goal is to deliver high-quality measurement solutions with integrity and customer care at the forefront.
See our Terms & Conditions of Sale and learn how we put transparency and customer protection first.
Ready to experience precision and peace of mind?
Read more about how our customer-focused terms can help support your business needs.
IP + Patents
We’re proud to play a small part in helping improve precision and quality in the field of ophthalmics. Our patents in this field center around:
- Evaluation of optical elements
- Wavefront sensing
- Interferometric measurement methods
- Measuring and mapping 3D structures
- Metrology of surface flatness and nanotopology of materials
Browse our list of intellectual property below.
- Non-Contact Thickness Measurement
- Crystal Wave
- ClearWave Plus
- Lumetrics Wavefront Sensors
Lumetrics, Inc. Non-contact Thickness Measurement Intellectual Property
| Patent # | Date Issued | Title | Description |
| 11,215,444 | 1/4/2022 | Apparatus and method for measurement of multilayer structures | A method of identifying the material and determining the physical thickness of each layer in a multilayer structure is disclosed. |
| 10,761,021 | 9/1/2020 | Apparatus and method for measurement of multilayer structures | A method of identifying the material and determining the physical thickness of each layer in a multilayer structure is disclosed. |
| 10,190,977 | 1/29/2019 | Method of measurement of multilayer structures | A method of identifying the material and determining the physical thickness of each layer in a multilayer structure is disclosed. |
| 10,006,754 | 6/26/2018 | Associated interferometers using multi-fiber optic delay lines | An interferometer apparatus which include two or more coupled fiber optic Michelson interferometers using fiber optic stretches which stretch two or more optical fibers wound around the perimeter of the optical fiber stretchers by the same amount is disclosed. |
| 9,958,355 | 5/1/2018 | Apparatus and method for evaluation of optical elements | An apparatus for measuring the optical performance characteristics and dimensions of an optical element comprising a low coherence interferometer and a Shack-Hartmann wavefront sensor comprising a light source, a plurality of lenslets, and a sensor array is disclosed. |
| 9,506,837 | 11/29/2016 | Topic intraocular lens measurement apparatus and method | An apparatus for determining the angular error in the placement of fiducial marks on a toric intraocular lens with respect to the true location of a meridional axis of the intraocular lens, the fiducial marks defining an estimate of the angular orientation of the meridional axis of the intraocular is disclosed. |
| 9,448,058 | 9/20/2016 | Associated interferometers using multi-fiber optic delay lines | An interferometer apparatus which include two or more coupled fiber optic Michelson interferometers using fiber optic stretches which stretch two or more optical fibers wound around the perimeter of the optical fiber stretchers by the same amount is disclosed. |
| 9,341,541 | 5/17/2016 | Apparatus and method for evaluation of optical elements | An apparatus for measuring the optical performance characteristics and dimensions of an optical element comprising a low coherence interferometer and a Shack-Hartmann wavefront sensor comprising a light source, a plurality of lenslets, and a sensor array is disclosed. |
| 9,019,485 | 4/28/2015 | Apparatus and method for evaluation of optical elements | An apparatus for measuring the optical performance characteristics and dimensions of an optical element comprising a low coherence interferometer and a Shack-Hartmann wavefront sensor comprising a light source, a plurality of lenslets, and a sensor array is disclosed. |
| 8,836,778 | 9/16/2014 | Portable fundus camera | A portable hand-held camera for imaging the fundus of an eye, the camera comprising a housing comprising an internal cavity terminating at a forward housing end, a forward lens, and a light source configured to direct light from locations distributed around the perimeter of the forward lens forwardly out of the housing end. |
| 8,610,889 | 12/17/2013 | Rotational and linear system and methods for scanning of objects | A scanning system comprised of a multi-axis drive module comprised of a first linear drive operable along a first axis, a second linear drive joined to the first linear drive and operable along a second axis non-parallel to the first axis, and a first rotary drive mounted on the second linear drive, operable around an axis parallel to the first axis, and comprised of a rotary fixture for holding the object. |
| 8,279,446 | 10/2/2012 | Fiber-based interferometric device for measuring axial dimensions of a human eye | An apparatus for measuring a layered object comprising a low coherence light source, a coherent light source, and an interferometer including a reference arm and a measurement arm. The reference arm is comprised of a first section of polarization maintaining optical fiber engaged with a first fiber stretcher. The measurement arm is comprised of a second section of polarization maintaining optical fiber engaged with a second fiber stretcher. |
|
8,199,329 |
6/12/2012 | Apparatus for measurement of the axial length of an eye | An apparatus for measuring the axial length of a human eye, the apparatus comprising a low coherence light source; a beam splitter; a fast displacement module for rapidly varying the path length within a reference arm of an interferometer; a laser directing a laser beam that is co-propagating with light from the low coherence light source into the displacement module. |
|
7,884,996 |
2/8/2011 | Apparatus for measurement of the axial length of an eye | An apparatus for measuring the axial length of a human eye, the apparatus comprising a low coherence light source; a beam splitter; a fast displacement module for rapidly varying the path length within a reference arm of an interferometer; a laser directing a laser beam that is co-propagating with light from the low coherence light source into the displacement module. |
|
7,206,076 |
4/17/2007 | Thickness measurement of moving webs and seal integrity system using dual interferometer | A system and method for measuring the thickness of materials and coatings across a moving length of material such as sheet, film, or web by the use of non-contact optical interferometry is provided. |
The CrystalWave product is used to measure an intraocular lens in the manufacturing process.
| Patent # | Expiration Date | Title | Description |
| 7,078,665 | 7/9/2023 | System and method of wavefront sensing for determining a location of focal spot | A computational method for finding a centroid |
| 6,819,413 | 8/29/2023 | Method and system for sensing and analyzing a wavefront of an optically transmissive system | A Shack Hartmann device for sensing a wavefront of light passed through an optical device |
| 7,455,407 | 4/21/2024 | System and method of measuring and mapping three-dimensional structures | A system for measuring an optical characteristic of an optically transmissive object |
| 7,122,774 | 9/19/2025 | System and method of wavefront sensing | Method for finding the center of the focal spot in a detector array |
| 9,506,837 | 4/16/2034 | Apparatus and method for determining angular error in placement of fiducial marks on a toric intraocular lens | An apparatus for determining the angular error in the placement of fiducial marks on an intraocular lens with respect to the true location of a meridional axis of the intraocular lens |
Lumetrics has designed and launched this product that combines the capability of an OptiGauge along with a wavefront sensor.
| Patent # | Expiration Date | Title | Description |
| 7,078,665 | 7/9/2023 | System and method of wavefront sensing for determining a location of focal spot | A computational method for finding a centroid |
| 6,819,413 | 8/29/2023 | Method and system for sensing and analyzing a wavefront of an optically transmissive system | A Shack Hartmann device for sensing a wavefront of light passed through an optical device |
| 7,455,407 | 4/21/2024 | System and method of measuring and mapping three-dimensional structures | Method for testing optically transparent optics using wavefront sensor. |
| 7,122,774 | 9/19/2025 | System and method of wavefront sensing | Method for finding the center of the focal spot in a detector array |
| 7,335,867 | 4/21/2026 | Method of wavefront sensing by mapping boundaries of a lenslet array onto a grid of pixels | Method for reconstructing a wavefront from the Shack Hartmann gradient data |
| 8,118,429 | 10/28/2028 | Systems and methods of phase diversity wavefront sensing | Method measuring an optic that changes power in time |
| 9,019,485 | 3/31/2033 | Apparatus and Method for Evaluation of Optical Elements | Apparatus and method comprising a low-coherence interferometer and wavefront sensor to measure properties of an optical element, 25 claims |
| 9,341,541 | 3/31/2033 | Apparatus and Method for Evaluation of Optical Elements | Apparatus and method comprising a low-coherence interferometer and wavefront sensor to measure properties of an optical element, 11 claims |
- Custom X/Y automated scanning system with manual Z probe mount with tip/tilt capability
- 1–50 mm probe
- Custom user interface using OptiGauge Control Center Tool Kit
| Patent # | Expiration Date | Title | Description |
| 7,078,665 | 7/9/2023 | System and method of wavefront sensing for determining the location of focal spot | A system and computational method for finding a centroid |
| 7,455,407 | 4/21/2024 | System and method of measuring and mapping three-dimensional structures | A system for measuring an optical characteristic of an optically transmissive object |
| 7,122,774 | 9/19/2025 | System and method of wavefront sensing | Method of estimating a location of a center of a focal spot on a detector array comprising a plurality of lenslets and a plurality of pixels adapted to receive light from the plurality of lenslets |
| 7,335,867 | 4/21/2026 | Method of wavefront sensing by mapping boundaries of a lenslet array onto a grid of pixels | Method for using focal spots in calculating the wavefront |
| 7,553,022 | 7/27/2027 | System and method of measuring and mapping three-dimensional structures | A system comprised of a projecting optical system adapted to project light onto an object |
| 8,118,429 | 10/28/2028 | Systems and methods of phase diversity wavefront sensing | A system for measuring an optic that changes power in time |
| 7,988,292 | 5/29/2029 | System and method of measuring and mapping three-dimensional structures | A system comprised of a projecting optical system adapted to project light onto an object; a pre-correction system adapted to compensate a light beam to be projected onto the object for at least one aberration in the object |
| 2016/0252425 A1 | 3/11/2033 | Apparatus and Method for Evaluation of Optical Elements | Continuation of 9,341,541 |
| 9,019,485 | 3/31/2033 | Apparatus and Method for Evaluation of Optical Elements | Apparatus and method comprising a low coherence interferometer and wavefront sensor to measure properties of an optical element, 25 claims |
| 9,341,541 | 3/31/2033 | Apparatus and Method for Evaluation of Optical Elements | Apparatus and method comprising a low-coherence interferometer and wavefront sensor to measure properties of an optical element, 11 claims |