Alternative Size Options
16 mm Kinematic Cage Mounts
30 mm Kinematic Cage Mounts
60 mm Kinematic Cage Mounts

Features

Ø2" (Ø50.8 mm) Optic Mount
Compatible with 60 mm Cage System

The Cage Assembly System provides a convenient way to construct large optomechanical systems with an established line of precision machined building blocks designed for high flexibility and accurate alignment. See the “Cage Overview” tab for a full definition of this widely adapted construction standard.

Our KC2 Series Mounts have been designed to allow for the precise angular positioning and high degree of flexibility of optics within a 60 mm cage system. They can be mounted onto our TR Series Posts using the 8-32 (M4) tapped mounting holes on three sides. Each mount has four through-holes compatible with our ER Cage Rods and include four 4-40 setscrews to lock them into place. Also featured on each mount are 100 TPI adjusters with a locking collet design and removable knobs.

The KC2 Kinematic Mirror Mount is a Ø2" version of the KC1. It provides ±3° of tip-tilt motion for a mounted Ø2" optic secured by the 8-32 (M4) nylon-tipped setscrew that is provided. The KC2-T Kinematic Mirror Mount provides similar functionality incorporating an SM2 internally threaded plate. This mount comes complete with two SM2RR retaining rings.

The KCB2 mounts 2" round mirrors. It features tapped holes for ER cage rods on both the entrance and exit ports for 60 mm cage system integration, as well as SM2-threaded entrance and exit holes for Ø2" lens tube integration. This mount has three 100 TPI adjusters, which allow for precise alignment of the mirror and makes this mount great for compensating beam path deviation in a 60 mm cage system.

The KCB2E is similar to the KCB1, but mounts 2" elliptical mirrors. It features tapped holes for ER cage rods on both the entrance and exit ports for 60 mm cage system integration, as well as SM2-threaded entrance and exit holes for Ø2" lens tube integration. This mount has three 100 TPI adjusters, which allow for precise alignment of the mirror and makes this mount great for compensating beam path deviation in a 60 mm cage system.

Cage System Compatibility: Thorlabs offers 16 mm, 30 mm, and 60 mm cage systems designed for Ø1/2", Ø1", and Ø2" optical components, respectively. The parts on this page are compatible with our 60 mm cage system and utilize Ø6 mm ER cage rods.

An example of the standard cage
plate measurements determining
cage system compatibility.

Cage System Overview

The Cage Assembly System provides a convenient way to construct large optomechanical systems with an established line of precision-machined building blocks designed for high flexibility and accurate alignment.

16 mm, 30 mm, and 60 mm Cage System Standards

Thorlabs offers three standards defined by the center-to-center spacing of the cage assembly rods (see image to right). The 16 mm cage, 30 mm cage, and 60 mm cage standards are designed to accomodate Ø1/2", Ø1", and Ø2" optics, respectively. Specialized cage plates that allow smaller optics to be directly inserted into our larger cage systems are also available.

Standard Threads

The flexibility of our Cage Assembly System stems from well-defined mounting and thread standards designed to directly interface with a wide range of specialized products. The three most prevalent thread standards are our SM05 Series (0.535"-40 thread), SM1 Series (1.035"-40 thread), and SM2 Series (2.035"-40 thread), all of which were defined to house the industry's most common optic sizes. Essential building blocks, such as our popular lens tubes, directly interface to these standards.

Standard Cage System Measurements
Cage System	16 mm	30 mm	60 mm
Thread Series	SM05	SM1	SM2
Rod to Rod Spacing	16 mm (0.63")	30 mm (1.18")	60 mm (2.36")
Total Length	25 mm (0.98")	41 mm (1.60")	71.1 mm (2.8")

Cage Components
Cage Rods	16 mm	These rods are used to connect cage plates, optic mounts, and other components in the cage system. The SR Series Cage Rods are compatible with our 16 mm cage systems, while the 30 mm and 60 mm cage systems use ER Series Cage Rods.
	30 mm
	60 mm
Cage Plates	16 mm	These serve as the basic building blocks for a cage system. They may have SM-threaded central bores, smooth bores sized for industry standard optics or to accommodate the outer profile of our SM Series Lens Tubes, or specialized bores for other components such as our FiberPorts.
	30 mm
	60 mm
Optic Mounts	16 mm	Thorlabs offers fixed, kinematic, rotation, and translation mounts specifically designed for our Cage Systems.
	30 mm
	60 mm
Cage Cubes	16 mm	These cubes are useful for housing larger optical components, such as prisms or mirrors, or optics that need to sit at an angle to the beam path, such as beamsplitters. Our cage cubes are available empty or with pre-mounted optics.
	30 mm
	60 mm
Post and Breadboard Mounts and Adapters		Mounting options for cage systems can be found on our Cage System Construction pages. Cage Systems can be mounted either parallel or perpendicular to the table surface.
Size Adapters		Cage System Size Adapters can be used to integrate components from different cage system and threading standards.
Specialized Components		Thorlabs also produces specialized cage components, such as Filter Wheels, a HeNe Laser Mount, and a FiberPort Cage Plate Adapter, allowing a wide range of our products to be integrated into cage-mounted optical systems. Explore our Cage Systems Visual Navigation Guide to see the full range of Thorlabs' cage components.