SM Series Angled Optic Mounts

  • 10° Angle Reduces Etalon Effects on Plano-Plano Optics
  • Eliminate Back Reflections
  • Accepts Optics up to 5 mm Thick






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  • Mounts Ø1" Optics at 10° Angle
  • Reduces Back Reflections and Etalon Effects in Plano-Plano Optics
  • Accepts Optics up to 5 mm Thick
  • SM1 (1.035"-40) Threaded
  • SM1RR Retaining Ring Included
  • SM1NT Locking Nut Included

The SM1L03T Angled Optic Mount is designed to minimize back reflections occurring from a Ø1" optical window by mounting it at a fixed, 10° angle. This mounted angle also helps reduce the etalon effects present in optics with parallel surfaces. The SM threading on the rear side allows the mount to be easily coupled to a Ø1" lens tube. Using our SM1 thread adapters, the mount can also be added to a Ø1/2", Ø2", or Ø3" lens tube setup. This mount accommodates optics up to 5 mm thick, making it compatible with many of our flat windows.

The etalon effect occurs when the front and back surfaces of a window or filter create Fresnel reflections that interfere with the original beam. Tilting a window with an angled optic mount reduces the etalon effect, and the output from the window or filter contains less interference, giving a smoother, more accurate baseline of the source. 

Since the beam exiting the angled window is displaced as a function of the thickness of the window and its material, Thorlabs recommends using the angled optic mount together with an XY Translating Mount such as the LM1XY to offset this displacement.

Posted Comments:
Jeff Jarboe  (posted 2020-01-28 10:37:23.803)
This is a interesting product and I would be interested in using these in a few applications but the angle is higher then desired. Has there been any interest or desire from industry to make a 2 or 5 degree version?
llamb  (posted 2020-01-28 04:31:34.0)
Thank you for your feedback. There have been a few requests over the years for smaller angles, though not a large volume. I have added your idea into our internal product forum for further review.
user  (posted 2020-01-15 17:00:17.17)
I second the 1/2 " version, although I like the 10 degree tilt. It would be good if it is placed in a such a way so that the optical axis goes through the center of the lens (with some nominal thickness, maybe 5 mm).
YLohia  (posted 2020-01-16 09:01:26.0)
Thank you for your feedback. I have posted your suggestion on our internal engineering forum for further discussion regarding offering a 1/2" version of this item as a product. That being said, the SM1L03T can be used with 1/2" optics using the SM1A6T adapter since the front of the mount is SM1-threaded.
tor  (posted 2011-01-05 19:56:57.0)
Response from Tor at Thorlabs to Boris: Thank you for your request. I will contact you directly to determine whether we can provide a custom part for your application.
btadjikov  (posted 2011-01-04 14:45:27.0)
Hi, I would like to have 1/2" version of SM series angled optics mount. Also, 10deg seems too big for most applications, 3-5 deg is enough. Regards, Boris Tadjikov, engineer Pranalytica, Inc.
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SM1L03T Support Documentation
SM1L03TSM1 Series 10° Angled Optic Mount
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