Fly's Eye Homogenizers
![](https://www.thorlabs.com/Images/GuideImages/15169_FLEs_1.jpg)
- Turns Round Collimated Input Beam into a Rectangular Output Area
- Two Continuously Adjustable, Rectangular Output Size Ranges
- Built-In Rotation Mount to Set Orientation of Output
FLE1
40 mm Working Distance, Uncoated
FLE21
95 mm Working Distance, 420 - 700 nm AR Coating
Application Idea
FLE2 Fly's Eye Homogenizer Mounted on an SM2TC Clamp, Projecting a Rectangular Output on an EDU-VS1 Screen
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![40 mm WD Fly's Eye Homogenizer](https://www.thorlabs.com/images/tabimages/FLE_A1-250.jpg)
Click for Details
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.
![Diagram of Fly's Eye Homogenizer](https://www.thorlabs.com/images/TabImages/FLE_D1-400.gif)
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.
![95 mm WD Fly's Eye Homogenizer](https://www.thorlabs.com/images/tabimages/FLE_A2-300.jpg)
Click for Details
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.
Item # | FLE1 | FLE11 | FLE12 | FLE2 | FLE21 | FLE22 |
---|---|---|---|---|---|---|
Working Distancea | 40 mm | 95 mm | ||||
Output Beam Sizeb | 2.9 mm x 4.0 mm - 11.4 mm x 16.0 mm | 6.4 mm x 9.0 mm - 25.7 mm x 36.0 mm | ||||
Input Beam Diameter | 2 mm - 9 mm | |||||
Microlens Array Used | MLA1 | MLA11 | MLA12 | MLA1 | MLA11 | MLA12 |
Microlens Array Substrate (Click for Transmission Plot) |
PMMA | |||||
Operating Wavelength Range (Click for Plot) |
350 - 1600 nm (Uncoated) |
420 - 700 nm (AR Coating) |
650 - 1050 nm (AR Coating) |
350 - 1600 nm (Uncoated) |
420 - 700 nmm (AR Coating) |
650 - 1050 nm (AR Coating) |
Reflectance (Average)c | - | <0.8%, 0° AOI | <0.8%, 0° AOI | - | <0.8%, 0° AOI | <0.8%, 0° AOI |
Input Thread | Internal: SM05 (0.535"-40) External: SM1 (1.035"-40) |
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Output Thread | External SM1 (1.035"-40) | External SM2 (2.035"-40) | ||||
Housing Dimensions | ||||||
Input Housing Diameter | 30.5 mm (1.20")d | |||||
Output Housing Diameter | 30.5 mm (1.20")d | 55.9 mm (2.20")e | ||||
Housing Length | 52.3 mm (2.06") | 107.2 mm (4.22") | ||||
Mounting Optionsf | SM1RC(/M), SM1TC, CP36, SM2A21 | SM1RC(/M), SM1TC, CP36, SM2RC(/M), SM2TC, LCP36, SM2A21 |
![Fly's Eye Homogenizer Setup](https://www.thorlabs.com/images/TabImages/FLE1_CagePlate_A1-400.jpg)
Click to Enlarge
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.
Posted Comments: | |
Alastair Curnock
 (posted 2024-05-01 15:01:26.94) Good Afternoon,
Would be be possible to get a custom version of the FLE2 Homogeniser with Fused SIlica MLAs (eg MLA150-5C) and a suitable equivalent Fused Silica output lens? srydberg
 (posted 2024-05-02 03:54:51.0) Hello, thank you for your feedback! I have contacted you directly to discuss your request. Gyeongwon Lee
 (posted 2023-11-30 12:57:12.267) Hello. Could I get the spatial profile after passing through the homogenizer? fnero
 (posted 2023-12-04 03:06:04.0) Thank you for reaching out. The Zemax files for the Fly's Eye Homogenizers can be downloaded from the website and there it is possible to simulate this. For further help, you are welcome to reach out to techsupport.se@thorlabs.com. user
 (posted 2023-11-24 12:53:21.73) Hello,
could you provide safe temperature range where no damage to the component will occur, estimate is also fine.
Thank you. mkarlsson
 (posted 2023-11-29 01:22:21.0) Thank you for your question! The operation temperature range is likely limited by the PMMA microlens array. Below 70°C I believe you would be safe. user
 (posted 2023-10-05 15:14:56.25) Hello, I have a similar question with a posted comment.
I would like to maintain the collimation of the squre beam profile about a meter long. Woud it be possible? Thank you. jeklof
 (posted 2023-10-11 02:56:57.0) Thank you for your inquiry. Unfortunately with the Fly’s Eye principle it is not practicable to get a sharp homogeneous rectangle in 1m distance. user
 (posted 2023-09-27 10:40:44.11) Hello,
we recently bought your FLE22, and we like what it does, but it doesn't fit properly to our needs. Basically the focal distance is too short for our application. I saw that you are selling the same microlens arrays separately, and we were thinking if we could build a cage system, with those arrays and different optics / lenses to expand the focal point to meet our needs. Basically the distance should be approx 250mm vs. 95mm which the FLE22 is providing.
also, with such a cage set up we see that we could integrate additional components. Could you please contact me and let me and provide support in the design , if possible?
thanks fnero
 (posted 2023-09-28 09:39:25.0) Thank you for your interest in our microlens arrays. We have contacted you directly to discuss your application. user
 (posted 2023-05-02 08:06:31.613) Is the imaging lens removable? Is it possible to replace it with other lenses? tberg
 (posted 2023-05-03 04:01:22.0) Thanks for contacting Thorlabs!
No, the front lens of our current line of Fly's Eye Homogenizers is not removeable. I have reached out to you directly to discuss your application. user
 (posted 2023-04-08 22:06:38.217) Can the output beam be collimated while maintaining the same top-hat profile as the one observed at the system's working distance? fnero
 (posted 2023-04-12 10:54:37.0) Thank you for your question. Outside the focal plane of the focusing lens the sharp edges of the homogenous area becomes blurry. We have contacted you directly to discuss your application in detail. user
 (posted 2023-04-08 21:54:50.8) Would it be possible to get some graphs of the spatial profile of the output beam? How efficient is the system in generating the top-hat profile and how the profile differs from the Engineered Diffusers? Thank you. fnero
 (posted 2023-04-12 10:53:01.0) Thank you for contacting us. We provide Zemax files on the web for these components where you can analyse the beam profile. We have reached out to you to further discuss your application. |
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Item # | Output Beam Size | Input Beam Diameter | Microlens Array Used | Operating Wavelength Range (Click for Plot) |
Reflectance (Average)a |
Input Thread | Output Thread (External) |
---|---|---|---|---|---|---|---|
FLE1 | 2.9 mm x 4.0 mm - 11.4 mm x 16.0 mm |
2 mm - 9 mm | MLA1 | 350 - 1600 nm (Uncoated) | - | Internal: SM05 External: SM1 |
SM1 |
FLE11 | MLA11 | 420 - 700 nm (AR Coating) | <0.8%, 0° AOI | ||||
FLE12 | MLA12 | 650 - 1050 nm (AR Coating) | <0.8%, 0° AOI |
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Item # | Output Beam Size | Input Beam Diameter | Microlens Array Used | Operating Wavelength Range (Click for Plot) |
Reflectance (Average)a |
Input Thread | Output Thread (External) |
---|---|---|---|---|---|---|---|
FLE2 | 6.4 mm x 9.0 mm - 25.7 mm x 36.0 mm |
2 mm - 9 mm | MLA1 | 350 - 1600 nm (Uncoated) | - | Internal: SM05 External: SM1 |
SM2 |
FLE21 | MLA11 | 420 - 700 nm (AR Coating) | <0.8%, 0° AOI | ||||
FLE22 | MLA12 | 650 - 1050 nm (AR Coating) | <0.8%, 0° AOI |
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Several mounting options for the Fly's Eye Homogenizers are provided in the table below. For our complete selection of thread adapters, see our Optical Component Thread Adapters selection guide.
Item # | SM1RC(/M) | SM2RC(/M) | SM1TC | SM2TC | CP36 | LCP36 | SM2A21 |
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Photo (Click to Enlarge) |
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Application | Slip Ring for Post Mounting | Clamp for Post Mounting | 30 mm Cage Mount for Ø1.2" Housing | 60 mm Cage Mount for Ø2.2" Housing | Mount Fly's Eye Homogenizer in Ø2" or SM2-Threaded Optic Mounts |
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Compatible Fly's Eye Homogenizers (Item # Prefix) |
FLE1 FLE2 |
FLE2 | FLE1 FLE2 |
FLE2 | FLE1 FLE2a |
FLE2 | FLE1 FLE2 |
Internal Bore / Threads |
Ø1.2" Bore | Ø2.2" Bore | Ø1.2" Bore | Ø2.2" Bore | Ø1.2" Bore | Ø2.2" Bore | Ø1.2" Bore |
- | - | - | - | - | - | SM2 Threads and Ø2" Smooth Surface |
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Mounting Holes | 8-32 (M4) Tap | #8 (M4) Counterbore | Compatible with 30 mm Cage Systems |
Compatible with 60 mm Cage Systems |
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