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A Day In The Life Of An Optical Filter

Here I am! A 550FS10-12.5 premium high quality optical bandpass filter, built and designed by Andover Corporation, ready to take on the world! I will be used across the globe in machine vision, helping others by identifying spoiled fruits & vegetables and only letting edible produce make it to the grocers’ shelves. But how did I get here?

It all started when a shipment of soda lime glass arrived at 4 Commercial Drive in Salem New Hampshire. Most soda lime glass ends up as a windowpane, a light bulb, or a drinking glass. Little did I know the contribution to the world I was about to make. My soda lime glass was carefully unpacked and thoughtfully looked over for scratches, digs, staining or any other defects that would hinder my ultimate purpose. I was then introduced to my counterpart, a dull piece of orange filter glass that I was to pair up with. Now a “couple”, we were off to the washroom. It was the equivalent of a day at the spa for humans!

In the Washroom we were given a bath. A gentle scrub with chalk and aerosol to remove any of the road dirt and oils, followed by a high-speed spin to dry us off, which prepared us to be the world class filters I knew we would become! Next, it was on to another inspection. We were looked over for cleanliness and any smaller scratches that were missed. From here we were separated for a little while, my other half was off to Polishing while I was headed over to receive the optical thin film that would help me perform my job!

In Polishing, the technicians started off by grinding the orange Schott glass down with great precision to the exact thickness required for the job. This was followed by a few rotations on the lapper and a massaging polish that helped by smoothing out any lines created from the grinding. This resulted in the incredible flatness and the beautiful translucence that would be critical in our future.

Meanwhile in the Coating Room, I was gently laid into a snug carrier and loaded into a state-of-the-art vacuum deposition chamber. The chamber looked like the most exciting rollercoaster I would ever experience in my entire life. Once the chamber door was closed, they started spinning me at an incredible speed! Man was I dizzy! The highly trained technicians started evaporating material, creating layers on me that would produce the bandpass filter necessary for effective machine vision. Once that was over, it was time to go to Quality Control for a quick checkup. The specialists here wanted to ensure that my wavelength was precisely what the job required. In this room it was all business, so much so that I felt I should be wearing a tie!

Next, I was brought upstairs to Lamination where I was finally reunited with my other half! After her pampered trip to Polishing, she sure looked amazing! No longer a dull matte finish, instead she was a stunning orange color with the perfect flatness needed for the work we were going to do. A lamination technician applied a high-quality optical grade epoxy to bond us together forever! We were then allowed to nap in a cozy oven overnight to accelerate the curing time.

From there, we were brought down to Grinding and Coring where we were shaped into what would be our final dimensions. Another stop at a high-speed spin machine that gently ground down our outside diameter until we were perfect! Next, it was back to Lamination, where we were presented with our ring, making our relationship official of course. Our ring was engraved with our technical product information, part number and the company name of Andover Corporation, who made this all possible!

There was one final inspection left, where our wavelengths and clear aperture were checked one last time! We received our final cleaning and were looked over for any possible cosmetic defects; and then gently packed away in a protective case proudly bearing the name and logo of our company. Then off to the Shipping Department ready to make a lasting impact on the world.

I never knew, until now, how much hard work was involved, or how much expertise it took, to get me where I am today. But now that I know, I could not be any prouder to call myself a 550FS10-12.5 Andover Optical Filter!




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