- Circular, Continuously Variable, Reflective Neutral Density Filter
- Optical Density Range: 0 - 4.0
- Ø50 mm Filter Wheel
- Designed for Use with SM1 Lens Tubes and 30 mm Cage Systems
Thorlabs' Round, Continuously Variable, Metallic (i.e., reflective) Neutral Density Filters for Cage Systems are specifically designed for compatibility with our SM1 (1.035"-40) Lens Tubes and 30 mm Cage Systems. They are composed of a UV fused silica glass substrate with a metallic Inconel coating through a full 270°, ensuring a flat spectral response from the ultraviolet to the mid-infrared. These filters have optical densities ranging from 0 to 4.0.
The circular filter wheel measures 50 mm in diameter and is attached to a rotating lever arm so that it can be moved out of the beam path. The rotating axle comes with angular graduations that improve repeatability. In addition, an M4 tapped hole is provided in the base to allow for mounting to Ø1/2" TR Series Posts and accessories. The plates on either side of the filter wheel contain an internally threaded SM1 port and have four through holes that allow mounting to our Ø6 mm ER cage system assembly rods.