Small Optic Mounting Adapters

  • Stainless Steel Adapters for Ø2 to Ø10 mm Optics
  • Outer Diameters of 1/2" or 18 mm Available
  • Optics Secured in Adapter with Epoxy


Adapts Ø2 mm Optics to Ø1/2" Mounts


Adapts Ø3 mm Optics to Ø1/2" Mounts


Adapts Ø5 mm Optics to Ø1/2" Mounts


Adapts Ø7 mm Optics to Ø1/2" Mounts


Adapts Ø8 mm Optics to Ø1/2" Mounts


Adapts Ø10 mm Optics to Ø18 mm Mounts

Application Idea

Epoxy is used to affix optics to our small-optic adapters which are then mounted in an LMR05 mount.

Related Items

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LMRA8 Being Attached in a Mount with Internal SM05 Threading
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An Ø8.0 mm lens is epoxied into an LMRA8 Adapter and then inserted into an internally SM05-threaded component.


  • Mounts Non-Standard Optics into Our Standard Threaded Ø1/2" Optic Mounts
  • Ø1/2" Adapters are Compatible with SM05 Lens Tubes
  • LMRA10 Adapter Mounts into Ø18 mm Optic Mounts
  • Mounts for Ø2 mm, Ø3 mm, Ø5 mm, Ø6 mm, Ø6.35 mm, Ø7 mm, Ø7.4 mm, Ø8 mm, Ø9 mm, or Ø10 mm Optics
  • Glue Ports Provided to Secure Optic into Housing

Thorlabs' small-optic mounting adapters are designed to mount non-standard optic sizes into Ø1/2" or Ø18 mm Mounts. Each stainless steel adapter includes two or three reservoirs next to the lens cell to secure the lens in place with General Purpose or UV Curing epoxy. Simply place a drop or two of adhesive into each reservoir located next to the lens in the adapter. We recommend using our NOA61 UV curing adhesive and MS403-10 epoxy syringe.

The Ø1/2" Optic Mounting Adapters featured below are compatible with our LMR05 (LMR05/M) or MLH05 (MLH05/M) Lens Mounts, SM05 Lens Tubes, or 16 mm Cage Components. The LMRA10 is compatible with our LMR18 (LMR18/M) mount, AD18T adapter, or SM1AD18 adapter. Please see the table below for all compatible mounting options. Once the optic is secured in the small-optic adapter, the new assembly is held in one of these threaded mounts using an SM05RR or SM18RR Retaining Ring. 

Alternatively, Thorlabs offers internally threaded, post-mountable fixed mounts, which do not require the optics to be epoxied into place, for mounting optics from Ø5 mm to Ø4".

Incorporating Small Optics into Lens Tube Systems
In addition to providing a means for mounting small optics in our LMR series of lens mounts, the LMRA series of adapters (with the exception of LMRA10) are directly compatible with our SM05 Series Lens Tubes, making it possible to insert Ø2 - Ø9 mm optics into a lens tube system.

Item # Optic Diameter Clear Aperture Outer Diameter Thickness Compatible Mounts
Typ. Max
LMRA2 2 mm 2.05 mm Ø1.8 mm (Ø0.07") 12.7 mm
2.2 mm
MLH05 Lens Mount
LMR05 Lens Mount
SM05 Lens Tubes
16 mm Cage Components
LMRA3 3 mm 3.05 mm Ø2.4 mm (Ø0.11")
LMRA5 5 mm 5.05 mm Ø3.8 mm (Ø0.15")
LMRA6 6 mm 6.07 mm Ø4.8 mm (Ø0.19")
LMRA6.35 6.35 mm 6.4 mm Ø5.4 mm (Ø0.21")
LMRA7 7 mm 7.03 mm Ø6.0 mm (Ø0.24")
LMRA7.4 7.4 mm 7.41 mm Ø6.4 mm (Ø0.25")
LMRA8 8 mm 8.02 mm Ø7.0 mm (Ø0.28")
LMRA9 9 mm 9.01 mm Ø7.9 mm (Ø0.31")
LMRA10 10 mm 10.03 mm Ø8.8 mm (Ø0.35") 18 mm
2.5 mm
LMR18 Lens Mount
AD18T Adapter
SM1AD18 Adapter

Posted Comments:
Lyle Nay  (posted 2023-11-15 10:28:12.743)
Here's an idea for another customer inspired product. It would be nice if you offered your LMRA Small Optic Mounting adapters with an external thread so that they could be screwed directly into the SM05 tubes. This would make them much easier to focus. You would not need to remove the lens mount to adjust the lock ring position. You would simple screw the lens mount into the tube, adjust the focus position with a spanner wrench and lock it in place with a single ring.
jdelia  (posted 2023-11-16 10:04:45.0)
Thank you for contacting Thorlabs, and for providing this feedback. This is indeed a good idea. While this is not something we currently offer, I could certainly forward your request over to our design engineers via our internal suggestion forum for consideration as a future catalog item.
bdada  (posted 2011-04-12 17:34:00.0)
Response from Buki at Thorlabs to Johannes: We recently introduced some adapters that make it easier to use 5 to 20mm diameter optics with our SM1 and 30mm Cage system. We will update our web page with these additional mounting options. Below is the link to the adapters. I have also matched the adapter to the lenses you mentioned: AL1210: SM1A6T AS1512: SM1AD15 AL1815: SM1AD18 AL2018: SM1AD20 The adapters come with two retaining rings each for holding the lens in place. You can use our adjustable spanner wrench, SPW801, to conveniently thread the retaining rings. Please contact if you have further questions.
johannes.piel  (posted 2011-04-12 16:37:55.0)
And how about adapters to SM1? I need to use 30 mm cage system and would like to adapt AL1210, AL1512, AL1815, AL2018 to SM1 or dia 1" or 25mm. But there seems to be no alternative way than do-it-youself...
jjurado  (posted 2011-03-14 13:16:00.0)
Javier Jurado: Response from Javier at Thorlabs to cguertin: Thank you for submitting your inquiry. We currently do not offer a direct adapter for 10 mm optics to SM05 lens tubes and mounts. However, there is a very straightforward way of mounting the ACL108 into an SM05 lens tube like the SM05L20. You can use two SM05LTRR stress-free retaining rings, one of each side of the optic, to secure the optic in place. Keep in mind, however, that he clear aperture of the lens will be slightly reduced. SM05LTRR: Alternatively, we recently added a few small optic adapters for our SM1 threaded lens tubes and mounts, including one for 10 mm diameter optics. Please follow the link for our SM1AD10 adapter below:
cguertin  (posted 2011-01-10 12:46:21.0)
How about a SM05 adapter for 10mm diam optics? Specifically, how would you mount ACL108 in SM05L10?
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Small Optic Adapters

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
LMRA2 Support Documentation
LMRA2Ø1/2" Adapter for Ø2 mm Optics
LMRA3 Support Documentation
LMRA3Ø1/2" Adapter for Ø3 mm Optics
LMRA5 Support Documentation
LMRA5Ø1/2" Adapter for Ø5 mm Optics
LMRA6 Support Documentation
LMRA6Ø1/2" Adapter for Ø6 mm Optics
LMRA6.35 Support Documentation
LMRA6.35Ø1/2" Adapter for Ø6.35 mm Optics
LMRA7 Support Documentation
LMRA7Ø1/2" Adapter for Ø7 mm Optics
LMRA7.4 Support Documentation
LMRA7.4Ø1/2" Adapter for Ø7.4 mm Optics
LMRA8 Support Documentation
LMRA8Ø1/2" Adapter for Ø8 mm Optics
LMRA9 Support Documentation
LMRA9Ø1/2" Adapter for Ø9 mm Optics
LMRA10 Support Documentation
LMRA10Ø18 mm Adapter for Ø10 mm Optics