Products: Athermal Lens Tubes

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Three SM1 Lens tubes are compared. The left lens tube is made of ALLVAR Alloy 30 and the right is made of aluminum. Each have a 0.85" air gap between lenses. By shifting the lenses to the left and right, the CTE of the housing in between lenses can be shifted between +7 and -23 ppm/°C. An example even shows a zero CTE spacing between lenses.

Control CTE like never before!

ALLVAR Alloy 30 SM1 Lens Tubes are designed to give you a new tool in your toolbox for athermal design. These lens tubes give you the power of ALLVAR Alloy 30, our commercially available titanium alloy that exhibits a negative coefficient of thermal expansion. This means that along its axis it will shrink when heated and expand when cooled. 

  • Enables CTE tailoring of athermal systems
  • Negative CTE (-30 ppm/°C) Lens Tube
  • Great for breadboarding ALLVAR Alloy 30 in your design
  • Standard SM1 Lens Tube Sizing
  • Stackable with standard SM1 Lens tubes (1.035″-40) threaded components

How do ALLVAR Lens Tubes help athermalize optics?

ALLVAR created these ALLVAR Alloy 30 lens tubes to make your life easier while delivering great optic performance. Prototyping and breadboarding with ALLVAR Alloys athermalized optics is simple.

With these SM1 Lens Tubes, you will have complete control over the athermalization of your system. These lens tubes are compatible with lens tubes from the large optomechanical suppliers that you know and love, are already machined, and ready for you to breadboard your newest, athermal system.

Control CTE like never before! When threaded with other lens tubes in series, designers can effectively choose the desired CTE between lens elements! Want a zero CTE from the front lens to your sensor? What about a negative housing CTE to counteract the coefficient of thermal defocus of your lenses? With ALLVAR Alloy 30 Lens Tubes, the CTE of your housing can be made to perfectly match your chosen lens assembly.    

Choose your own CTE!

Tailoring the CTE within the lens tube is as simple as shifting the location of the lenses inside. The diagram to the right exemplifies the wide range of CTE tuning possible with ALLVAR Alloy 30.

In this case, two 1″ diameter doublets were chosen to sit within a lens assembly. The ALLVAR Alloy 30 SM1 lens tube (left) is threaded onto the aluminum lens tube (right) available from a large optics supplier. The doublets sit a constant distance of 0.850″ between lenses to maintain focus. These two 1” lens elements are mounted inside with standard retaining rings.

In the top example, the lens elements are situated with slightly more of the air gap between elements in the aluminum housing. The rest is the ALLVAR housing. This configuration yields a zero CTE between lens elements.

The CTE was tailored to be more negative in the middle configuration, in this case -23 ppm/°C. The shift occurs because the to incorporate more ALLVAR Alloy 30 in the lens housing between elements and very little positive CTE aluminum,

In the bottom lens tube configuration, the lens elements are shifted further to the left to incorporate a small portion of the ALLVAR and majority aluminum. This results in a 7 ppm/°C CTE.  

Ready to learn more? We’ve put together a handy guide titled “Introduction to Tailored Thermal expansion” which will teach you to calculate how much ALLVAR you need relative to the other material in your design to create your customized CTE!

Three SM1 Lens tubes are compared. The left lens tube is made of ALLVAR Alloy 30 and the right is made of aluminum. Each have a 0.85" air gap between lenses. By shifting the lenses to the left and right, the CTE of the housing in between lenses can be shifted between +7 and -23 ppm/°C. An example even shows a zero CTE spacing between lenses.

Custom Lens Tubes

Would you like to order a lens tube specific for your prototype or design? Need a different size or thread? ALLVAR can help. Please fill out the form below and let us know what size and length lens tube you need.

SM1 Lens Tube Specifications

We have manufactured a limited series of 1” SM1 Lens tubes as a commercially-off-the-shelf item. Simply order the parts, and we will ship them to you ASAP. No customization required.

Part Number CTE Length Internal Thread Depth Description Price
Part Number
CTE
Length
Internal Thread Depth
Description
Price
AV-SM1L10
-30
1.15″
1.00″ (25.4 mm)
SM1 Lens Tube, 1.00″ Thread Depth
$979.00

Request a Quote

Please fill out the following information. We will follow up with a formal quote for the above SM1 Lens tubes. If custom lens tube is needed, please list each in the additional information field.

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