These bases allow 30 mm and 60 mm cage plates to be directly mounted to an optical table, optical breadboard or mini breadboard surface without the use of a post. Each base has a lip in order to prevent the rotation of the cage plate when subjected to a torque.
| System Size of Compatible Cage Plates* | Item # | Description | Optical Axis Height |
|---|---|---|---|
| 30 mm | CPB1 | Cage Plate Base for 30 mm Cage Plates | 1.15" (29.4 mm) |
| 60 mm | LCPB1 | Cage Plate Base for 60 mm Cage Plates | 1.75" (44.5 mm) |
* Compatible cage plates are square and have an 8-32 tapped hole on the edge for our or 30 mm and 60 mm cage plates.

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.
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.
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. | |

The CPB1 and LCPB1 bases for 30 mm and 60 mm cage plates, respectively, can be attached directly to an optical table or breadboard with 1/4"-20 tapped holes on 1" centers. Similarly, the CPB1/M and LCPB1/M bases for 30 mm and 60 mm cage plates, respectively, can be attached directly to an optical table or breadboard with M6 tapped holes on 25 mm centers. In addition, the LCPB1 (LCPB1/M) is compatible with the height adapters below that allow 16 mm and 30 mm cage plates to be mounted so that their optical axis height coincides with the optical axis height of a 60 mm cage plate mounted on an LCPB1 (LCPB1/M) base.
The image to the right shows an LCP01 cage plate mounted on a LCPB1 base.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
CPB1 |
Cage Plate Mounting Base for 30 mm Cage Plates, Imperial |
$15.00 |
Today |
LCPB1 |
Cage Plate Mounting Base for 60 mm Cage Plates, Imperial |
$19.00 |
Today |
CPB1/M |
Cage Plate Mounting Base for 30 mm Cage Plates, Metric |
$15.00 |
Today |
LCPB1/M |
Cage Plate Mounting Base for 60 mm Cage Plates, Metric |
$19.00 |
Today |