SM2-Compatible Cage Plates


SM2 Lens Tube Compatible Cage Plates

  • Mount SM2 Lens Tubes in a 60 mm Cage System
  • Version with Ø2.2" Bore for Slide-In Lens Tube Mounting


  • Integrate SM2 Series Lens Tubes with 60 mm Cage Systems
  • Compatible with ER Series Cage Construction Rods

SM2-Threaded (2.035"-40) cage plates and cage cubes allow SM2 Lens Tubes to be integrated into 60 mm Cage Systems by threading the lens tube into the plate. Alternatively, the LCP09 cage plate has a Ø2.2" bore through the part, which allows an SM2 lens tube to be slid into it and then locked in place.

Thorlabs introducted the SM Series Threading standards to ensure compatibility over a broad range of product lines. SM Series Threaded components offer a simple and efficient solution for building optomechanical structures. The SM Threaded products available, including lens tubes and cage system components, fixed and kinematic mounts, irises and diaphragms, provide flexibility when constructing complex optical systems.


60 mm Threaded Cage Plate, 0.5" Thick


  • Directly Accepts Ø2" Optics up to 0.35" (8.9 mm) Thick
  • Mount Bulk Optics Within a 60 mm Cage System Assembly
  • Tapped with our Standard SM2 (2.035"-40) Thread
  • Post Mountable with an 8-32 (M4) Tapped Hole

The LCP01(/M) is among our most popular 60 mm cage plates. It provides a center-located SM2 (2.035"-40) threaded bore that accepts a Ø2" optic up to 0.35" (8.9 mm) thick and is compatible with our popular lens tubes. Two SM2RR retaining rings are included that are used to hold an optic within the cage plate. Each cage rod through hole is accompanied by a side-located locking 4-40 setscrew, which can be secured using a 0.05" hex key. For additional convenience, an 8-32 (M4) tapped hole is provided for post mounting and OEM-mounting applications. As shown in the family image at the top of the page, the LCP01/M has a small dimple to indicate that it is a metric part.


60 mm Cage Plate with Ø2.2" Bore


  • Ø2.2" Bore Supports Outside Diameter of SM2 Lens Tubes
  • Compatible with 60 mm Cage Systems
  • Nylon-Tipped Setscrew and Double Bore Securely Hold Lens Tubes
  • Not Post Mountable

The LCP09 Cage Plate is designed to allow our SM2 lens tubes to slide into the cage plate and be locked in position with a nylon-tipped setscrew. This cage plate is ideal for situations where it is not desirable to thread the lens tube into one of our threaded cage plates. A double-bore design gives three points of contact for stable and secure mounting. Each cage rod through hole is accompanied by two side-located locking 4-40 setscrew, which can be secured using a 0.05" hex key.

Please note that this plate does not feature a tapped mounting hole, unlike many of our other cage plates. Due to the bore size, there would be interference between the threaded stud on our Ø1/2" posts and the clear aperture of the bore. Therefore, this cage plate cannot be used directly with Ø1/2" Posts, and a cage system utilizing this plate must be supported using a different method.


60 mm Cubes


  • Four SM2-Threaded Ports
  • Two Opposing Faces Threaded for 60 mm Cage Rods
  • Ø6 mm Through-Holes~Mounts to Ø6 mm ER cage rods

The LC6W is a 60 mm cage cube designed for building 2D cage systems while providing a means to mount optics such as beamsplitters inside. Two opposing faces have tapped holes to accept ER cage rods, while the other two opposing faces offer through holes. This allows for 1D translation of a section in a cage assembly. The eight included 4-40 setscrews are used to secure the cube to the cage rods that pass through the through holes of the cage cube.


60 mm Cage Plate, Quick Release Magnetic Plate


  • 60 mm Cage Compatible Back Plate
  • Magnetically Coupled Mounting Carriage
  • Accepts Ø2" (50.8 mm) Optics Up to 0.345" (8.7 mm) Thick
  • Angular Repeatability Better Than 1 µrad
  • Lateral Repeatability Better Than 10 µm in X, Y, and Z
  • Back Plate and Mounting Carriage Have Internal SM2 Threading
  • One Retaining Ring (SM2RR) Included for Mounting 2" Optics

The LCP90F consists of a back plate compatible with the 60 mm cage system and a mounting carriage (front plate) that is magnetically coupled with pairs of rare earth magnets to the back plate. For stability, precision, and repeatability, the mounting carriage contacts the back plate at three points. Each point of contact is a ball bearing on the mounting carriage resting in the groove formed by two parallel steel pins. Since the axes defined by the three sets of pins share a common point of intersection, the system is properly constrained (kinematic). The mounting carriage can be easily inserted or removed from the fully assembled cage system by separating it from the back plate, rotating it sideways, and then extracting it from the cage.

The internal SM2 threading allows components up to 0.345" (8.7 mm) thick to be secured in the mounting carriage with the included SM2RR retaining ring. Components with external SM2 threading (OD = 2.2" (55.9 mm)) cannot extend more than 1" (25.4 mm) beyond the face of the mounting carriage without sacrificing the ability to remove the mounting carriage and component from a closed cage system. The lateral repeatability specification (10 µm) indicates that the X, Y, and Z position of the mount will not vary by more than 10 µm after being removed and replaced, while the 1 µrad angular repeatability refers to the rotation of the optic not changing by more than 1 µrad.

Both the LCP90F and LCP90F-B have four cage rod through holes that are accompanied by a side-located locking 4-40 setscrew, which can be secured using a 0.05" hex key.


60 mm Cage Mount with Quick-Release Clamp


  • Compatible with 60 mm Cage Systems
  • Internal SM2 Threading
  • Dovetail Design Provides Smooth Release and Clamping Action
  • One-Handed Operation for Removal and Repositioning of an Optic
  • Accepts Ø2" (Ø50.8 mm) Optics Up to 0.15" (3.8 mm) Thick
  • One Retaining Ring (SM2RR) Included for Mounting 2" Optics

The QRC2A cage mount is equipped with a spring-loaded dovetail clamp that secures or releases the cage mount to two of the four ER rods in the cage structure. The cage plate has internal SM2 threading that allows for components up to 0.15" (3.8 mm) thick to be secured with the included SM2RR retaining ring. In addition, components up to 1" (25.4 mm) thick [not including length of threaded stub, OD = 2.2" (55.9 mm)] with external SM1 threading can be attached without sacrificing the ability to remove the cage plate from a closed cage system.


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