The Lumenarium Blog

Optical Thickness and Flatness Measurement of Bonded Silicon Wafer Assemblies

AbstractThe silicon wafer manufacturing process relies heavily on precision polished wafers that have uniform thickness and, depending on the application, also control parallelism to a secondary wafer after bonding.
Lumetrics’ low coherence interferometer, commercially marketed as OptiGauge II, is a device capable of measuring the simultaneous wafer thickness, adhesive thickness, and parallelism between surfaces to sub-micron precision. Combined with custom software and a precision XY raster scanner, a wafer or wafer assembly can be fully characterized with respect to layer thicknesses and surface parallelism.
Index Terms—adhesive, flatness, interferometry, metrology, optical thickness measurement, parallelism, silicon, wafer

I. Introduction:

Lumetrics is the market leader in providing high-precision, non-contact optical thickness measurements to medical, scientific, and ophthalmic industries.

A unique capability of our flagship thickness measurement device, OptiGauge II, is its ability to measure the individual layer thickness of a multiple-layer sample.

The OptiGauge II measures using a 1310nm wavelength. This is an ideal wavelength for measuring through nearly all visually transparent and semi-transparent objects.

A visually opaque material that is highly transmissive at 1310nm is silicon. This makes silicon an ideal sample for optical thickness measurement.

Download the application note now!

Lumetrics exhibiting at Photonics West 2017

Photonics West LogoPhotonics West 2017 is just around the corner and Lumetrics will be exhibiting in booth #616 from January 31st through February 2nd at the Moscone Center in San Francisco, CA. Lumetrics will be showcasing the OptiGauge® II as well as a live demonstration with the CLAS-IR adaptive optics, operating at telecom wavelengths.

We will be offering sample measurement demonstrations with your own samples using the OptiGauge II.  If you would like to set up a complimentary sample measurement session using your own samples, please click here to make your appointment.

Entrance to the Photonics West 2017 Exhibition is free.  Please click here to register for your pass to visit the Lumetrics booth.

Data Relay Application by Clark Cianfarini

How Lumetrics developed the Data Relay application to meet the needs of a customer who needed to use a non-windows based system.

Lumetrics Data Relay SoftwareSoftware is often a crucial, yet overlooked component to any industrial equipment. At Lumetrics, we pride ourselves on creating quality software that is both robust and intuitive to use. During the early years at Lumetrics, all of our customers needed Microsoft Windows based software. We focused all our resources on that software and quickly became entrenched in Microsoft products. This worked very well for us, as it gave us a single platform that was easy to use by our customers and easy to manage by their IT groups.

A few years ago, we were approached by one customer that needed to use a non-Windows based system. A customer had never made a request like this before, so there were no Lumetrics products available to meet this need. To redevelop all of the existing Lumetrics software for different operating systems would have been time and cost prohibitive. Instead of turning away the customer, several Lumetrics engineers were able to think of a solution that would not take a lot of development time.

The solution was an ASCII-based protocol over a TCP/IP socket connection. In simple terms, it was a series of text commands to control the OptiGauge core unit and receive data. The talented developers at Lumetrics were able to quickly develop all of the commands and structure for a system that is extremely easy to use by the customer.

At the end of the project, the customer was able to get a fully working solution on-time and on-budget. They were very happy with the system and have purchased more OptiGauges since.

The product was the Data Relay. Since the initial request Lumetrics has continued to develop and enhance this software package and is now better positioned in the market to offer solutions to all customers.

If you’re in need of a solution like this customer, please visit our official store to view our Data Relay application.

Lumetrics, Inc. launches new Web Store for its Thickness and Wavefront Measurement Equipment

August 15, 2016, Rochester, NY: Lumetrics Inc., the leading manufacturer of precision measurement solution equipment known for offering precision thickness and wavefront measurement instrumentation, is proud to announce the launch of its highly anticipated Web Store. Lumetrics’ Web Store allows customers to easily order probes, fixtures, software, and other accessories in the U.S. (please note that web store shipments are limited to shipments to US State & territories). Lumetrics plans on adding international ordering to the Web Store in the future.

Lumetrics, Inc. Web Store brings customers a hassle-free way to purchase non-contact thickness measurement and wavefront measurement systems.

Web Store Link:
Lumetrics’ Web Store offers a complete line of accessories for their OptiGauge thickness measurement systems and Wavefront measurement systems; the ClearWave, CrystalWave, and CLAS-2D. Customers will also have access to special “on-line exclusive” items from time to time.

“We are excited to launch online shopping in the U.S.,” says Steve Kelly, Vice President of Sales Marketing for Lumetrics. “For those customers who are able to pay via credit card the, Web Store provides a more efficient alternative to the traditional Purchase Order process.

“Our customers will be able to place their orders on-line and complete transactions in just a few minutes. The Web Store provides customers with twenty-four-hour access to our products from anywhere in the U.S.” To kick off this launch Lumetrics is offering a 10% discount on orders placed on the Web Store through September 15th
About Lumetrics
Lumetrics® is the leading metrology equipment manufacturer with total solution engineering expertise dedicated to the medical device, ophthalmic, glass, and film industries. Lumetrics® engineers are experts in designing custom metrology fixtures and data analysis packages for online or at-line thickness measurement applications. Lumetrics is known worldwide for its proven metrology expertise including its non-contact measurement system – the OptiGauge®. Lumetrics also provides wavefront analysis of intraocular lenses, contact lenses, and laser beams in various industry, government, and independent research labs.

Lumetrics’ systems are deployed in many diverse manufacturing environments including quality assurance departments, R&D laboratories, and production floors. The real-time measurements provided with Lumetrics’ metrology systems help customers improve yield, reduce costs, improve product quality, and meet regulatory compliance requirements. From medical balloons and catheters to contact lenses, adhesives, or food packaging, Lumetrics works with industry partners and customers to design, fabricate, and test gauging fixtures and data analysis packages for a wide range of applications.

Please email, visit, or call 585-214-2455 x121 for more information.

To view the original Lumetrics web store launch announcement, click here.

Custom probe design used in-situ at plastic injection molding facility

Plastic Injection Molding Probe by LumetricsA customer approached Lumetrics with a desire to better understand the thickness profile during the molding process of manufacturing a plastic bottle. Due to cycling mechanical machinery within a 24-inch window around the pre-form, a standard probe (with standoff maximum of 2 inches) could not be used while the machine was running.

Lumetrics designed a custom probe with a standoff distance of over two feet that could be mounted to allow in-situ wall thickness measurement of molten pre-formed plastic bottles just prior to the blow molding operation and the customer was able to obtain thickness data at discrete areas of the bottle and generate the required thickness profile to generate their molding simulation to further understand the science behind their molding process and optimize their feed, pressure, and temperature profiles in their molding machine.

By utilizing Lumetrics OptiGauge technology for thickness measurements the customer was able to significantly reduce their line start up costs as well as reduce the amount of scrap materials based on more accurate real time measurement data. The OptiGauge allows them to fine-tune their setup in a matter of minutes versus the previous hour or more setup time. This is just one example of how Lumetrics delivers cost savings to its customers through the use of our precision metrology solutions.

Lumetrics Principal Opto-Mechanical Engineer, Kyle Hadcock

Wedge Angle Measurement by Lumetrics Principal Scientist, Dr. Michael Marcus

Precision Wedge Angle Measurement, Lumetrics, Inc.A customer approached Lumetrics with a need to determine  and certify the precision wedge angle measurement of low angle wedges in the range of 0.5 – 3.5° with a high degree of accuracy.   A custom fixture was designed and constructed which included x, y, z  and rotation stages with micrometer precision position feedback as shown in the diagram. 

The procedure developed for measuring the Wedge Angle is a three-step process including: (1) Measuring the index of refraction of the wedge using the Lumetrics Refractive Index Calculation System (RICS).  (2)  Placing the wedge in the wedge measurement fixture, finding the approximate center of the wedge and then determining the wedge axis by rotating the wedge axis so that the measured thickness variation along the direction of the y axis is minimized.  (3) Move back to the approximate center of the wedge and measure the optical thickness at 2 defined locations near the edges of the wedge at opposite ends of the x axis a known distance apart.  The software then calculates the thickness of the wedge at each of the defined locations and the wedge angle.  This measurement procedure and fixture meet the customers needs for wedge angle certification

Please email for more information if you have a similar measurement need or have questions!  Lumetrics has expanded the solutions offered to service a broad variety of glass thickness measurement and dimensional measurement needs.  For more information on our glass measurement capabilities, view our glass thickness measurement page, read this article on wedge angle measurement, or call us at (585) 214-2455 or (866) 524-2455

ClearWave Plus: A brand new contact lens measurement solution

contact lens measurements, clearwave plus, wavefront measurement from Lumetrics, optigauge

The ClearWave™ Plus uses a modified ClearWave in combination with the industry standard OptiGauge®

Lumetrics, the leading provider of precision measurement instrumentation, is pleased to announce a new metrology solution for the Ophthalmic market.  The ClearWave™ Plus uses a modified ClearWave in combination with the industry standard OptiGauge® thickness measurement system to provide contact lens measurements. This new instrument provides contact lens manufacturers with the ability to measure center thickness (CT), Sagittal Height (SAG), diameter, radius of curvature, and all the wavefront measurements that currently require three separate systems to obtain.

Our ClearWave & OptiGauge systems have been implemented in the world’s leading contact lens manufacturers R&D laboratories and production facilities. The ClearWave Plus provides the best of these products in a single operator friendly solution that results in less handling of the contact lens. The ClearWave Plus has been designed for fast and accurate measurement of contact lenses.

Our Technology Development Scientist, David Compertore, will be demonstrating the Clearwave Plus at the European Federation of the Contact Lens and IOL Industries Trade Show (EFCLIN)  in Valencia Spain April 28-30, 2016.

For more information, please email or visit our new ClearWave Plus product page!

Custom Precision Probe with Built-In Reference

The successful implementation of non-contact thickness measurement and precision measurement solutions for our customers is heavily dependant on our team of hard-working and talented Engineers.  The following application summary is from one of our Opto-Mechanical engineers after working with a customer to design a custom solution for their critical measurement challenges.

non contact thickness measurement, precision measurement, Lumetrics

A custom measurement probe that Lumetrics’ engineers designed for a customer.

Custom Precision Measurement Probe with Built-In Reference

A customer asked Lumetrics to design a probe to mount to a robotic arm that would move to specific coordinates to take thickness measurements on an assembly line. The probe had to be precise enough to give accurate and repeatable readings at all locations. It was also critical that if a probe was replaced on the robotic arm that no adjustments would need to be made to the robotic arm’s coordinates.

Lumetrics designed a precision probe with a built-in reference, so the user could always measure the exact distance from the probe to the material. The probe had a custom mounting flange integrated onto it to attach to the robotic arm. An offline test fixture was also designed for the user to verify the accuracy of the probe during down time of the robotic arm. The probe and test fixture were delivered in a quick turnaround time to meet the customer’s needs. (Opto-Mechanical Engineer, Jeremy Crouse)

This project was successful as it solved the customer’s measurement needs in order for their operation to:

  • Improve efficiency in their manufacturing process by integrating measurement on their production line.
  • Assure a quality product, thus reducing the likelihood of costly safety recalls or non-compliance issues.
  • Improve tolerances to reduce another costly manufacturing problem of shrink.

All of those improvements allowed our customer to manufacture a great product and maximize profit margins.

Does your manufacturing operation have unique measurement challenges?  Do you want to be sure we can provide the measurements you need?  We provide free sample measurements using your own products and/or materials!  Send us an email at for more information!

Successful applications: Custom automated test system

A customer needed a custom automated test system to reduce the inspection time during the setup of their production mold tools. At the time they were using a semi-automated system that would take 10-15 minutes to measure all 10 cavities of the mold tool. Lumetrics was asked to reduce the measurement time to 10 seconds or less with the use of our OptiGauge technology as well as add some addition measurement and functional capabilities.

Lumetrics’ engineering team met this challenge head on and developed an automated test system that met or exceeded all customer expectations. To meet the customer requirements, we developed a custom multiport probe head that allows the OptiGauge to measure the 10 cavities in less than 10 seconds. Our computer engineering team developed custom software and user interface based on operator feedback during development.

The original two systems were installed three years ago and continue to run well. Recently we developed a second generation of these machines adding in features based on feedback from the operators. Some of the features added were a touch screen, increased automation and sensors to streamline the process for the operators. The operators are so happy with the upgrades that while Lumetrics was onsite for the site acceptance test the operators were asking when the first two units would be upgraded. This was followed up by a quote request from management.

With our overwhelming success at this facility, there are now six active systems being used by this customer in their facilities across the globe.

Report by: John Solpietro, Senior Opto-mechanical Engineer

Lumetrics, Inc. releases new product, the OptiGauge® LT

OptiGauge LT non-contact thickness measurement system from Lumetrics

The OptiGauge® LT is the newest non-contact thickess measurement system from Lumetrics, Inc.

March 10, 2016, Rochester, NY: Lumetrics’ newest non-contact thickness measurement system is now available to customers seeking the capabilities of OptiGauge® technology, as well as integration with their own desktop and laptop computers. The OptiGauge LT builds on the proven technology of the OptiGauge® MLS and offers added flexibility to meet the needs of a diverse customer base.

“Customers have told us they want the capabilities of the OptiGauge MLS but with the ability to use their own PC or Laptop,” said Steve Kelly, Vice President of Sales and Marketing, “they also want to be able to quickly integrate the system into their production lines. With PC independence and USB connectivity, they are able to do that.” Kelly explains further that “this expanded product offering positions Lumetrics to better meet the constantly evolving needs of our customers. Our dedication to customer service and to innovation are why we lead the industry in precision thickness measurements.”

A key advantage of the new product is that it no longer requires a dedicated OptiGauge Controller and can be operated with the customers’ own PC or laptop. Lumetrics’ engineers have also improved the overall design and functionality which equates to an even more robust thickness measurement system in the field.

The OptiGauge LT has a measurement range of 12 microns to 5 mm optical thickness with an accuracy of ± 2 micron. This allows offers customers a more economical measurement system. As with our recently introduced OptiGauge II system, you can choose from a full selection of measurement probes to fit your application. The OptiGauge LT offers outstanding performance and value for lab and R&D applications.

View full press release and product data sheet

Women in Optics: Mary Banning Friedlander developed multi-layer low reflecting coatings

Mary Banning Friedlander, multi layer films

Mary Banning operates the knife switches powering one of the evaporators at the Institute of Optics, circa 1944. [Mary Banning Friedlander/Opt. News 13(6), 10 (1987).]

Rochester, New York is not just the “birthplace” of the thriving optics industry as we know it today, it’s also where the inclusion of women in STEM fields got its start. In 1941, Mary Banning Friedlander (FKA Mary Margaret Banning), a Physics Ph. D. from Johns-Hopkins University began her short but wildly successful career in optics and went on to develop multi-layer low reflecting coatings.

Once the United States officially joined Allied forces in the war, tensions ran high as the country struggled to develop new military technology to help defeat their enemies on the battlefield. One important optics contribution (among many) that came from Rochester were the multi-layer low reflecting coatings that Friedlander developed during her tenure at the Institute of Optics. These multi-layer films were used in military rangefinders and several other defense applications. Friedlander’s work in optics also contributed to solving another very critical issue for the U.S. Military: how to land in hostile territory in complete darkness without being detected by the enemy.

For more information on Mary Banning Friedlander’s career and achievements in optics, head over to read an in-depth article by Sarah Michaud and Stewart Wills at The Optical Society of America website.

Upcoming Event: Photonics West 2016

Lumetrics will be exhibiting at Photonics West this February in Booth #3018!  Please stop by and say hello- we have lots of new measurement solutions for your manufacturing process.

Please email or to set up an appointment or for more information on sample measurements!

If you haven’t registered- make sure you get registered for free here:

photonics west 2016, Thickness Measurement, non-contact thickness measurement, optical thickness measurement

Measuring Windshields with Heads up Displays

glass thickness measurements

Lumetrics handheld probe holder with 50mm Probe

Since the formation of the National Highway Traffic Safety Administration in 1970, the NHTSA has implemented regulations impacting all areas of vehicle safety including automotive glass.  The OptiGauge helps with the process by obtaining highly accurate glass thickness measurements to ensure glass is to manufacturer’s specifications.

For years windshields have been comprised of two pieces of glass approximately 2mm thick with an approximately 1mm layer of vinyl sandwiched in-between.  Today, many windshields include another thin, sound absorbing vinyl layer that helps reduce road noise.

Now technology and driver safety intersect on the windshield.  Heads Up Display (HUD) windshields provide drivers with access to important dashboard information such as speed and navigation while providing the safety benefit of maintaining eyes on the road and reducing driver distractions.

In order to maximize optical quality, HUD windshield technology requires further advancements in windshield manufacturing.  The most notable requirement is the ability to insert a wedge shaped polymer (Polyvinyl butyral – PVB) between the glass sheets. This wedge shape eliminates the “ghost” reflections that normal windshields produce when using HUD.  The problem then becomes how to measure the wedge or thickness of the laminate from top to bottom.  The generally accepted practice of using a micrometer to measure the laminate thickness at the top and bottom of the windshield now becomes obsolete as manufacturers need to measure thickness across the whole windshield from top to bottom in a non-destructive manner.  

Lumetrics invented the OptiGauge® which provides highly accurate and reliable glass thickness measurements with our custom solutions to meet the many needs of windshield glass manufacturers.  First we have provided multiple systems to the largest PVB manufacturers in the world to measure the wedge angle in the PVB as it is being produced.  Additionally, we have sold more systems to the auto glass manufacturers, who make the windshields.   The OptiGauge assists these cusglass thickness measurementstomers with product development, optical quality, and troubleshooting lamination problems.

The Lumetrics OptiGauge is based on the theory of time domain interferometry to produce highly accurate (.01micron accuracy) measurements.  For more information or a demonstration please contact Lumetrics –, 585-214-2455.

Measurement of Bioresorbable Stents

bioresorbable stentsMetal stents have been available since 1988.  Through the 1990’s, stents went through numerous iterations, incorporating different metals and coatings.  As the medical products industry moved through the 2000’s, the use of bioresorbable stents became the newest innovation.  And, it is a tremendous innovation.

Through the use of bioresorbable stents, physicians are able to reduce or eliminate anti-platelet drugs, maintain the flexibility of the blood vessel, and lessen risks and complications of future surgical events.  Absorption of the stent into the body within a one to two year period provides tremendous advantages to the patient and physician.

Lumetrics® has been working with medical device customers since 2004 on non-contact tools to non-destructively test and measure bioresorbable stents in all stages of development and manufacture to ensure proper functionality.  Lumetrics uses a high power LED to make measurements within our custom designed, precision optical interferometer.  The OptiGauge® is the ideal tool to measure all critical parameters in bioresorbable scaffolds.

OptiGauge measurements are:

  • Objective – NIST traceable
  • Accurate – 0.01 microns
  • Rapid – up to 200 samples per second
  • Non-contact and non-destructive
  • Cost saving and risk reducing

The OptiGauge thickness measurement system provides measurements of Inside Diameter, Outside Diameter, wall thickness, ovality, and concentricity of any tube material.  All measurements can be provided online, at-line, or off-line.  Lumetrics designs custom fixturing for any application with its team of seasoned hardware and software engineers.  Contact Lumetrics to find out more about our non-destructive bioresorbable scaffold measurement solutions.

New OptiGauge product introduced: OptiGauge II

OptiGauge II non contact thickness measurement systemThe OptiGauge II non contact thickness measurement system is ideal for companies looking to move away from traditional contact measurement systems. It is non-destructive and objective, leaving no margin for operator error. It offers customers extraordinary flexibility in a measurement system. This user-friendly system delivers reliability and sub-micron accuracy so vital to today’s most advanced industries. OptiGauge II can be particularly useful in in Quality, R&D labs, and production floors because it can improve yields, reduce costs, increase quality, and meet compliance requirements.  View the press release on our new product announcement!

A detailed spec sheet and product data sheet can be found here, and if you have further questions, you can email us or call us at +1 585-214-2455


Integrated Photonics Institute will be Headquartered in Rochester, NY

On Wednesday, July 22 2015, Representative Louise Slaughter’s office announced that Rochester, NY won a very arduous battle to be named the headquarter for the new Integrated Photonics Institute In Manufacturing Innovation (IP-IMI).  New York Photonics published a comprehensive article (with links to other relevant articles about the project):

In a hotly contested competition that had a team led by New York State vying with a team led by Florida and another led by Southern California, the DoD has chosen the New York team as the winner for the Integrated Photonics Institute In Manufacturing Innovation:  AIM Photonics. Congresswoman Louise Slaughter and Senator Chuck Schumer have announced National Manufacturing Institute in Photonics to be located in New York and headquartered in Rochester.

The complete article (and other links) can be found here.

Rochester celebrates the International Year of Light

New York Photonics blog posted a great article on the events in Rochester surrounding the International Year of Light celebration- here’s a brief overview and link to the full article written by Tom Battley.

In 2014 NYPhotonics began working on (or instigating) a number of projects for the International Year of Light in Rochester. A broad view looks like this:

  • Rochester Museum & Science Center IYOL2015 Advisory Committee
    OPI Company Tours in May 2015
  • Illuminations, a permanent exhibition of interactive OPI science demonstrations previewing now in the Patricia Hale Gallery at RMSC
  • Cubes: A Visual Exploration of Possibility at the Rochester Contemporary
  • A Street Light Festival (July 17 & 18)
  • “..of Light” a commissioned piece of music for Jazz Ensemble by Dave Rivello, Assistant Professor of Jazz and Contemporary Media, Eastman School of Music. This piece will debut during two performances in Kilbourn Hall during the First Niagara Fringe Festival on Friday, September 18th.

For the full article, click here!

Lumetrics, a spin-off supplying high precision gauging

When the products you make have to be of a precise thickness, that’s where a company like Lumetrics comes in.

Lumetrics develops and manufactures high-precision thickness measurement and gauging systems for a variety of industrial applications. The Henrietta-based firm’s clients include companies that make items like contact lenses, medical devices, and glass products. Read original article here.

Lumetrics Obtains Patent for Wavefront Sensor Contact Lens Measurement System

Lumetrics was awarded a patent for an apparatus that measures the optical performance characteristics and dimensions of an optical element using a Shack-Hartmann wavefront sensor and a low coherence interferometer. This is a major improvement on current manufacturing inspection methods, especially for the contact lens and intraocular lens industries. Read More

How We Can Use Light to See Inside the Human Body (Gizmodo)

Human flesh is opaque. As any good dictionary will tell you, that means it has the quality of “not transmitting light; being impenetrable to sight.” Well, forget that: scientists now can use light to see inside objects that were traditionally off-limits to the human eye—including our bodies.

Of course it’s already possible to use X-rays, MRI, ultrasound and the like to peer inside human beings, but results are never as crisp and clear as those acquired using visible light imaging. Not only that: optical wavelengths also interact with organic molecules—the one we’re made of—so visible light could also contain vital information about the tissue it travels through. It might reveals abnormalities in cells, say, or use information about bodily functions—something that other imaging techniques, such as MRI, resort to complex chemical tracers to achieve. And, perhaps most importantly, it’s also non-ionising, which is to say that, unlike X-rays and CT scans, it doesn’t increase cancer risk at the intensities used for imaging.  

Read more of this article from Gizmodo

“Roc” the Year of Light 2015 in Rochester

IYL2015 The international year of light is a global initiative to increase awareness and education on the many ways light effects our world.  Rochester, being a huge player in the world of optics, has a great website if you want to get involved in activities surrounding the international year of light.  Check out the site:  Roc the YOL