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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)
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.