Fly's Eye Homogenizers

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The 40 mm working distance fly's eye homogenizers have an externally SM1-threaded output. The input is internally SM05-threaded and externally SM1-threaded.

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A simple diagram of the homogenizer operation is shown above. Decreasing the distance of the two MLAs will increase the size of the rectangle and increasing the distance will make the rectangular area smaller.

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The 95 mm working distance fly's eye homogenizers have an externally SM2-threaded output. The input is internally SM05-threaded and externally SM1-threaded.

Features

• Two Ranges of Rectangular Output Sizes Available:
  • 2.9 mm x 4.0 mm to 11.4 mm x 16.0 mm
  • 6.4 mm x 9.0 mm to 25.7 mm x 36.0 mm
• Offered Uncoated or Broadband AR Coated:
  • Uncoated for 350 - 1600 nm
  • AR Coated for 420 - 700 nm
  • AR Coated for 650 - 1050 nm
• Beam Size Adjustment Ring Includes Engraved Scale
• Built-In Rotation Mount to Set the Orientation of the Rectangular Output
• Beam Size Adjustment Ring and Rotation Mount can be Locked with Included Hex Key
• SM Threads at Input and Output for Easy Integration into Optical Systems

Thorlabs' Fly’s Eye Homogenizers transform a collimated round input beam into a rectangular output beam with a top-hat intensity distribution. The size of the output can be varied from 2.9 mm x 4.0 mm to 11.4 mm x 16.0 mm for the FLE1(x) homogenizers or from 6.4 mm x 9.0 mm to 25.7 mm x 36.0 mm for the FLE2(x) homogenizers.

The FLE1 and FLE2 Uncoated Fly’s Eye Homogenizers have an operating wavelength range of 350 to 1600 nm. Alternatively, to reduce surface reflections, the homogenizers are also offered with broadband antireflection (BBAR) coatings that provide <0.8% average reflectance per optic surface from 420 to 700 nm (Item #s FLE11 and FLE21) or 650 to 1050 nm (Item #s FLE12 and FLE22).

These homogenizers are composed of two polymethyl methacrylate (PMMA) microlens arrays (MLAs) and a positive focal length lens. PMMA MLAs are excellent for homogenizing and shaping light into a rectangular output as well as filtering out UV light (see the PMMA transmission graph in the Specs tab). The actual size of the output can be adjusted by changing the distance between the two MLAs, accomplished by rotating the red ring on the homogenizer housing (visible in the photos to the right). Decreasing the distance will increase the size of the rectangle and increasing the distance will make the output rectangle smaller. A diagram illustrating the operating principle of these homogenizers is shown above. Once the desired rectangular size is obtained, the ring can be locked by tightening the locking screws using the included 0.05" hex key. The scale of the ring is engraved with increments from the smallest to the largest rectangular size.

To adjust the orientation of the rectangular output, the back portion of the housing can be rotated while the front SM1- or SM2-threaded portion of the homogenizer is fixed (click here for details). This built-in rotation mount can be locked with a locking screw using the included 0.05" hex key.

Mounting Options
All of these Fly's Eye Homogenizers have a smooth mounting surface with the same 1.2" outer diameter as our Ø1" lens tubes, providing compatibility with post mounting accessories such as the SM1RC(/M) Ø1" Lens Tube Slip Ring and SM1TC Ø1" Lens Tube Clamp and 30 mm cage system mounting accessories such as the CP36 Cage Plate (available below). The FLE2(x) homogenizers also have a Ø2.2 mm section of the housing at the output that is the same diameter as our Ø2" lens tubes, allowing them to be post mounted using the SM2RC(/M) Ø2" Lens Tube Slip Ring or SM2TC Ø2" Lens Tube Clamp or integrated directly with a 60 mm cage system using the LCP36 Cage Plate (available below). Please note that using the mounting surface at the output of the FLE1(x) homogenizer housing or in the middle portion the FLE2(x) homogenizer housing will block access to the rotation locking setscrew.

Other optomechanical and optical components, such as lens tubes, additional lenses, and filters, can be installed along the optical axis of each homogenizer using the threads at the input and output. The inputs of all of the homogenizers feature external SM1 threads and internal SM05 threads. The outputs of the FLE1(x) homogenizers are also externally SM1 threaded. Each FLE2(x) homogenizer output has external SM2 threads. Note that the input and output threads will rotate relative to each other when using the built-in output orientation adjustment.

The FLE2(x) Fly’s Eye Homogenizers can be used with a mounted LED and a collimation adapter to provide a uniform input into an Olympus, Zeiss, or Nikon microscope. We offer the SM2A8, SM2A10, or SM2A18 SM2-threaded port adapters to integrate the homogenizer on to the microscope.

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The FLE1 Fly's Eye Homogenizer can be used to transform a round Gaussian collimated beam into a homogenous illuminated rectangular area.

A fly's eye homogenizer, composed of two microlens arrays (MLAs) and a positive focal length lens, transforms a round collimated beam with a Gaussian profile into a homogenous illuminated rectangular area. The size of the rectangular output can be controlled by the red ring on the device.

The application photo to the right shows a configuration using an FLE1 fly's eye homogenizer mounted in a CP33(/M) 30 mm cage plate. The light source is a PL201 compact laser module fixed in an AD11F SM1-threaded adapter. An SM1T1 coupler attaches the laser module to the input side of the FLE1 homogenizer. Alternatively, other light sources can be used such as a fiber-coupled LED connected to a collimator or mounted LED with a collimation adapter. The light passes through the fly's eye homogenizer to produce a rectangular 8.6 mm x 12.0 mm output on an EDU-VS1(/M) screen, as seen in the photo to the right.

Please note that the homogenous illuminated rectangular area is an image of the first MLA, meaning the rectangle is sharply defined only at a certain working distance from the homogenizer. The actual size of the rectangle can be adjusted by turning the red Beam Size Adjustment ring of the homogenizer, which changes the distance between the two MLAs. Decreasing the distance will increase the size of the rectangle and increasing the distance will make the rectangle smaller.