30 mm Cage Cubes for Fluorescence Filter Sets

- Quickly Interchange Filter Sets with Repeatable Alignment
- Mounts Ø1" Round Optics and 25 mm x 36 mm Rectangular Optic
- 30 mm Cage System and Ø1" Lens Tube Compatible
DFM1
30 mm Cage Cube for Fluorescence Filter Sets, SM1-Threaded Ports
Cube Inserts and Base Also Available Separately
Magnetic Coupling Offers Repeatable Alignment of a Fluorescence Filter Set within a Cage System

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Each filter cube can hold a fluorescence filter set: one dichroic mirror, one excitation filter, and one emission filter.

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The DFM1 has two excitation (EX) and two emission (EM) filter ports. Ports labeled with the same number should be used together.
Features
- Kinematic 30 mm Cage Cubes for Holding Fluorescence Filter Set (Sold Separately)
- 30 mm Cage System and SM1 (1.035"-40) Lens Tube Compatible
- At Least One Emission Port with 3° Tilt to Reduce Undesired Reflections
- Individual Cube Inserts, Base, and Cover Plate Also Available
- Easily Swap Between Transmission and Left- or Right-Turning Reflection Paths
- 30 mm Cage Cube Connector for Connecting Two Cubes Side by Side (Sold Separately Below)
- Compatible with 30 mm Beamsplitter Cube, Right-Angle Optic Cube, and Beam-Turning Cube Systems
Thorlabs' DFM1(/M) and DFM1L(/M) Fluorescence Filter Cubes are designed to hold a fluorescence filter set (dichroic mirror, excitation filter, and emission filter) in a cage-system-compatible cube for home-built microscopy setups. Each filter cube consists of a base and removable insert that accepts fluorescence filter set components or other optics. Additional inserts are available to easily exchange alternate sets of optics within an aligned setup. This enables switching between fluorescence imaging of different wavelengths or changing the direction of the reflected light (see images in the subgroups below).
As shown in the animation to the right, the insert is designed to hold a rectangular optic, such as a dichroic mirror, beamsplitter, or silver mirror. The rectangular optic is clamped gently in place using a leaf spring that provides a uniform holding force to minimize stress. To mount the rectangular optic, remove the leaf spring using a Phillips #00 screwdriver and then insert the optic with the reflective coating face down. Only light force is needed to prevent the optic from moving; we recommend screwing in both screws most of the way before final tightening.
In addition, the cube insert has four ports for Ø25 mm filters. Excitation and emission filters can be mounted in two possible configurations (see the diagram to the right) and are held using the included SM1RR Retaining Rings, which can be tightened or loosened with our SPW606 or SPW602 Spanner Wrenches (sold separately). For the DFM1T1 Cube Insert, which is included with the DFM1(/M) Fluorescence Filter Cube, an emission port is oriented at a 3° angle with respect to the face in order to reduce undesired reflections; this port is labeled EM2 in the photo to the right. For the DFM1T3 Cube Insert, which is included with the DFM1L(/M) Fluorescence Filter Cube, both emission ports are oriented at 3° angles with respect to the face. To help keep track of your filter sets, spaces are provided on the top to write labels for the mounted filters and mirrors. The cube insert is designed to be inserted in a single orientation with respect to the cube base, so it is important to orient the full cube assembly in the proper direction. The cage cubes and cage cube inserts on this page are available with either a left- or right-turning orientation.
The base of these kinematic cubes has an SM1-threaded (1.035"-40) port on each face at an optical height from the base of 1.25" or 30 mm for the imperial or metric versions, respectively. These ports are compatible with our SM1 lens tubes. Four 4-40 tapped holes surround each port for compatibility with our 30 mm cage system. The cube base is equipped with three bottom-located 1/4"-20 (M6) tapped holes, which provide direct compatibility with our Ø1" posts or Ø1.5" posts. Alternately, an AE8E25E (AE4M6M) thread adapter (sold separately) can be used for compatibility with our Ø1/2" posts.
# | Product Description | Qty. | Photo (Click to Enlarge) |
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1 | DFM1 - Kinematic Fluorescence Filter Cube |
1 | ![]() |
2 | Microscopy Filters | 1 Set | ![]() |
3 | SM1B3 - Lens Tube Bellows | 1 | ![]() |
4 | SM1ZM - Non-Rotating SM1 Zoom Housing |
1 | ![]() |
5 | Focusing Lens Inside Zoom Housing |
1 | ![]() |
6 | ST1XY-D - XY Translator with Differential Drives |
1 | ![]() |
7 | Precision Pinhole Between XY Translator and Photodetector |
1 | ![]() |
8 | Photodetector SM1-Compatible Photodetector |
1 | ![]() |
DFM1 Filter Cubes - Optic Alignment in a Confocal Microscope Detection Module
The DFM1 is ideal for integrating filter sets into a custom microscopy setup. The following example of a partial confocal microscope uses a DFM1 Fluorescence Filter Cube (denoted by 1 in the image below) containing a Microscopy Filter Set (2) and an APD130A(/M) Photodetector (8). A lens (5) located inside the SM1ZM High-Precision Zoom Housing (4) focuses the beam onto a precision pinhole (7) located just before the avalanche photodetector's detector element. The SM1ZM zoom housing is mounted directly onto the ST1XY-D XY Translation Mount with Differential Adjusters (6), creating a compact XYZ mount. SM1 Lens Tubes and the SM1B3 Lens Tube Bellows (3) allow for a light-tight connection without inhibiting the free movement of the XYZ mount.
Components used in the configuration pictured below are listed in the table to the right. These parts, along with SM1 Lens Tubes and 1" Post Assemblies, are sold separately.

Posted Comments: | |
Felix Lauhoff
 (posted 2023-03-08 09:49:36.753) Hello ThorLabs-Team,
Do you can explain me why the emmissionport of the Filtercube is aligned 3° off-axis?
My guess is that light reflection into the objective prevented.
Thank you for your help. jdelia
 (posted 2023-03-09 04:12:23.0) Thank you for contacting Thorlabs. There is a 3 degree tilt to the emission port to reduce unwanted reflections in the end user's setup as you suggested. Basilio Javier Garcia
 (posted 2020-09-18 19:17:18.05) DFM1 filter cube application note seems to have a erratum.
It is probably a DFM1L cube instead a DFM1 one llamb
 (posted 2020-09-29 10:20:06.0) Thank you for your feedback. The "Applications" tab image and parts list does use the DFM1 cube. Its initial mounting happens to be used in a more "left-turning" orientation because of the location of the light source. I have reached out to you directly to discuss this further as well. Ben Garber
 (posted 2020-06-26 12:53:35.537) This mount is listed as kinematic but I don't see where the adjusters are to change the angle of the optic. Is it actually a kinematic mount, or do you just mean that the optic mount can be replaced? YLohia
 (posted 2020-07-09 09:40:54.0) Hello, thank you for your feedback. While the mirror mounts are removable, these cube mounts do not have tip-tilt ability. We will make this more clear in our documentation. |
Kinematic Cage Cubes Selection Guide (Click Image to Enlarge) | |||||
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Type | Empty Cubes for Fluorescence Filters |
Empty Cubes for Beamsplitters |
Empty Cubes for Right-Angle Optics |
Beam-Turning Cubes with Pre-Mounted Prism Mirrors | Multimode Fiber Optic Filter Cube |
30 mm Cage Cubes | ![]() Full Web Presentation |
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60 mm Cage Cubes | ![]() Full Web Presentation |
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The DFM1L Cube (Left Panel) and DFM1 Cube (Right Panel) used to direct a filtered beam to the left and right, respectively. Light from an MCWHL7 LED was directed via the MDF-TRITC Filter Set installed in each cube.
- Kinematic 30 mm Cage-Compatible Cubes for Mounting Fluorescence Filter Sets
- DFM1(/M): Right-Turning Orientation
- DFM1L(/M): Left-Turning Orientation
- Four 4-40 Tapped Holes Around Each SM1-Threaded (1.035"-40) Port Enable 30 mm Cage System Compatibility
- Three Bottom-Located 1/4"-20 (M6) Tapped Holes for Post Mounting
These Kinematic Fluorescence Filter Cubes each consist of a post-mountable cube base and a removable insert that mounts a fluorescence filter set (sold separately). The DFM1 holds a dichroic mirror in a right turning orientation, and the DFM1L in a left-turning orientation. Thus, using the DFM1 as opposed to the DFM1L results in a 180° difference in light output direction (see image to the right).

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Drawing of DFM1. The SM1-threaded ports on the DFM1/M are at an optical axis height of 30 mm.
DFM1(/M) & DFM1L(/M) Compatible Filters | ||
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Type | Dimensions | Thickness |
Excitation | Ø25 mm | 5.0 mm |
Emission | Ø25 mm | 3.5 mm |
Dichroic | Min: 25.0 mm x 35.6 mm Max: 25.2 mm x 36.0 mm |
Min: 1.0 mm Max: 2.0 mma |
See the table to the right for acceptable optic sizes. To see how optics are installed in the filter cubes, please see the animation in the Overview tab above. Prior to mounting the rectangular dichroic mirror, please confirm that the optic is no greater than 2.0 mm thick. To mount dichroic mirrors thicker than 2.0 mm, we recommend using our Dichroic Cage Cube.
The cube insert is designed to be inserted in a single orientation with respect to the cube base, so it is important to orient the full cube assembly in the proper direction.
All four sides of the filter cube base have an SM1-threaded port for compatibility with our Ø1" lens tubes. The SM1 port is centered between four 4-40 tapped holes for compatibility with Ø6 mm cage rods in a 30 mm cage system, at an optical axis height of 1.25" or 30.0 mm from the bottom of the imperial or metric cube, respectively.
Empty kinematic filter cube inserts, base, and a cover plate are also sold separately below.


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A DFM1T1 insert with an MDF-GFP filter set (left) or an MDF-TRITC filter set (right) can be swapped to change between imaging different fluorescent samples.
DFM1T1 & DFM1T3 Compatible Filters | ||
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Type | Dimensions | Thickness |
Excitation | Ø25 mm | 5.0 mm |
Emission | Ø25 mm | 3.5 mm |
Dichroic | Min: 25.0 mm x 35.6 mm Max: 25.2 mm x 36.0 mm |
Min: 1.0 mm Max: 2.0 mma |
- Empty Kinematic Base and Inserts for Exchanging User-Provided Filters or Mirror
- Ideal for Quickly Switching Fluorescence Filter Sets or Angle of Reflection in an Aligned Experimental Setup
- Cube Base with Four 4-40 Tapped Holes Around Each SM1-Threaded (1.035"-40) Port
- Three Bottom-Located 1/4"-20 (M6) Tapped Holes for Post Mounting
- Cover Plate for Uninterrupted Beam Transmission Available
These Kinematic Fluorescence Filter Cube Inserts (DFM1T1 and DFM1T3) and Base [DFM1B(/M)] allow users to switch between different filter sets in an aligned experimental setup (see image to the right). These items do not include fluorescence filters or a dichroic mirror.
See the table to the right for acceptable optic sizes in the cube inserts. To see how optics are installed in the filter cubes, please see the animation in the Overview tab above. Prior to mounting the rectangular dichroic mirror, please confirm that the optic is no greater than 2.0 mm thick. To mount dichroic mirrors thicker than 2.0 mm, we recommend using our Dichroic Cage Cube.
The cube insert is designed to be inserted in a single orientation with respect to the cube base, so it is important to orient the full cube assembly in the proper direction. Cage cube inserts that hold the dichroic mirror in a right-turning (DFM1T1) or left-turning (DFM1T3) orientation are available.
All four sides of the DFM1B(/M) cube base have an SM1-threaded port for compatibility with our Ø1" lens tubes. The SM1 port is centered between four 4-40 tapped holes for compatibility with Ø6 mm cage rods in a 30 mm cage system, at an optical axis height of 1.25" or 30.0 mm from the bottom of the imperial or metric cube, respectively.
For when a filter is not installed within the DFM1B(/M) cube base, we have the DFM1C Cage Cube Cover Plate to place on top. Additionally, we offer the SM1CP2 End Cap to minimize the amount of stray light entering through unused ports.


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Two DFM1-P01 Beam Turning Cubes Connected Using the C4W-CC Cage Cube Connector
- Connect Two Beam Turning, Fluorescence Filter, or Beamspliter Cubes Side by Side
- Remove and Interchange Cube Inserts while the Cube Bases are Connected
- Compatible with C4W and C6W Cage Cubes
The C4W-CC Cage Cube Connector allows two kinematic beam turning, fluorescence filter, or beamsplitter cubes to be connected together as shown in the image to the right. Two pins on the C4W-CC are accepted by drilled holes on either side of any of the SM1-threaded (1.035"-40) ports on the cage cube faces to maintain alignment. Cube inserts can still be removed and inserted while the cube bases are connected.
The C4W-CC is also compatible with our 30 mm cage cubes.