Dichroic Filters

  • Will Not Fade Like Gels or Plastic Filters
  • Multilayer Thin Film Coating on Glass Substrates
  • Also Available in Kits




Related Items

Please Wait

Click to Enlarge

Dichroic filters can be used with a white LED array to selectively illuminate a sample with a particular color.


  • Multilayer Thin Film Coating on Glass Substrates
  • Will Not Fade Like Gels or Plastic Filters
  • Ø1" Unmounted Filters Sold Individually
  • Mounted Filters Available in a Kit

Thorlabs offers high-quality Additive and Subtractive Dichroic Filters with a strong emphasis on durability. Unlike plastic filters or gels, these coatings will not fade with time and can handle much higher temperatures. Our dichroic color filters can be mounted in our Ø1" lens tubes or filter mounts.

Additive and Subtractive Dichroic filters are used to separate color in CCD imaging, digital projection, machine vision, and printing. These filters allow only a portion of the visible spectrum to pass and reject (reflect) the rest.

In the simplest case, using the Red, Green, and Blue additive filters in succession with a black and white CCD camera, a high-contrast color image may be achieved. Unlike the traditional color CCD, which uses groups of three spatially separated pixels to achieve this effect, using filters maintains the resolution of the camera. In digital projection, additive filters are used to enhance contrast. In machine vision, a single filter can be placed before the CCD camera to increase contrast, which makes sorting items much simpler. Often, copy machines and print preprocessing centers use subtractive filters to make the images that will later be printed in ink.

General Specifications
Angle of Incidence
Material Borofloat Glass
Surface Quality (Scratch-Dig) 80-50
Clear Aperture Ø22.9 mm
Temperature Range -50 to +80 oC
Diameter Ø25.4 mm +0/-0.25 mm
Thickness 2 mm +0.2/-0.5 mm
Individual Filter Specifications
Additive Filters Subtractive Filters
>75% avg. for 615-730 nm
<1% avg. for 380-550 nm
Cut-on: 585 ± 15 nm
>85% avg. for 390-530 nm
<1% avg. for 585-710 nm
Cut-off: 555 ± 15 nm
>70% @ peak
<1% avg. for 400-460 nm
Low Edge: 505 ± 15 nm
High Edge: 575 ± 15 nm
>75% avg. for 395-440 nm
and 645-750 nm
<1% avg. for 500-590 nm
>85% avg. for 390-480 nm
<1% avg. for 540-750 nm
Cut-off: 505 ± 15 nm
>85% avg. for 550-750 nm
<1% avg. for 410-475 nm
Cut-on: 515 ± 15 nm

Below are plots showing the percent transmission versus wavelength of our dichroic filters for four different angles of incidence (AOI). Please note that for clarity reasons we have only plotted data for four different AOIs. You can obtain raw data in 5o increments (i.e., at 0o, 5o, 10o, 15o, 20o, 25o, 30o, 35o, 40o, and 45o) by clicking on the link below the graph.

Posted Comments:
jon morris  (posted 2022-07-01 15:16:55.31)
which if any of these "mounted dichroic glass filters" will fit an ARRI field kit 650 Watt tungsten light housing in the existing scrim retaining slot. (to convert the tungsten 3200K to daylight 5500K output) I do not have access to the light right now, but my guess is that the scrims I have are approx. 6- 8" diameter. If you sell this item, what is you product # and current price with shipping to San Francisco, California?
Doyk Hwang  (posted 2019-12-05 11:06:16.65)
Hi there, Can we place a customized order for the thinner FD1M mirrors, like 0.5 mm thickness or less? Best, Doyk
nbayconich  (posted 2019-12-11 02:27:03.0)
Thank you for contacting Thorlabs. We can offer FD1M with 0.5 mm thickness. A Techsupport representative will reach out to you directly with more information.
Brian Mittelstaedt  (posted 2019-09-26 11:48:17.103)
When using the FD1G in front of a sensor, is there a preferred orientation? Is the spectral transmission the same regardless of which side faces the sensor?
YLohia  (posted 2019-09-30 09:56:11.0)
Hello, thank you for contacting Thorlabs. The spectral transmission will be the same regardless of orientation. That said, the best practice is to orient the coated side towards the incoming beam. Coated side can be differentiated by eye by tilting the part.
jing li  (posted 2019-03-16 04:50:11.64)
Hi, I bought FD1B filter which used to make a optical device, now I need do some analog computation of the device, could you tell me the thickness and refractive index of the film deposited on the mirror? Thank you!
nbayconich  (posted 2019-03-19 09:01:43.0)
Thank you for contacting Thorlabs. Unfortuntaely we cannot share specific index values or the thickness of our coating layers for these filters.
alexis.wartelle  (posted 2019-01-22 10:10:10.24)
Hello, I would like to know how these filters behave with respect to polarization, in particular with non-zero incidence angle. Does the transmission behaviour change for polarized light, depending on the polarization direction? Besides, the magenta and green filters would be valuable to me for a setup in which green light must be separated from blue and red light. I would like to know if the reflection from the filters behaves just like one expects from the transmission curves or if there are caveats. E.g: for incoming light with red, blue and green, if the magenta filter is set in at 45°, can one hope to get all the green light deflected by 90°? Best regards
llamb  (posted 2019-01-25 01:32:03.0)
Thank you for your feedback. When the Angle of Incidence is 0°, the transmission will be the same regardless of polarization. At non-zero AOIs, the transmission will depend on the input polarization states, though we do not currently have test data regarding this. Additionally, the beam will indeed reflect when outside of the standard transmission band, which should be usable in applications similar to yours. I will reach out to you directly to discuss your application further.
mss2257  (posted 2018-05-03 15:12:47.343)
Hi, I was wondering if more details could be obtained about the engineering of the dichroic filter? I plan on using this as a substrate in a reflectance experiment, and I would like to know the thicknesses of the optical materials deposited, and their refractive indeces, for calculation purposes.
YLohia  (posted 2018-05-08 08:40:52.0)
Hello, thank you for contacting Thorlabs. Unfortunately, we cannot share the thickness of coatings or their indices of refraction since that information is proprietary.
user  (posted 2015-04-07 05:56:40.03)
Is it possible to obtain transmission data above 800nm at AOI = 0° for the red, green and blue dichroic filters ?
jlow  (posted 2015-04-14 09:43:01.0)
Response from Jeremy at Thorlabs: We can provide more information about this. Since you did not leave your contact info, can you contact us at techsupport@thorlabs.com about this please?
Greg  (posted 2009-02-05 08:22:43.0)
A response from Greg at Thorlabs to acable: Our dichroic filter sets do not currently include a storage box.
acable  (posted 2008-12-15 16:11:58.0)
Does the kit come with a storage box to organize the optics.
Laurie  (posted 2008-10-01 16:16:10.0)
Response from Laurie at Thorlabs to cpontbriand: We have just added information to our website (see the Graphs Tab) showing transmission vs. wavelength for our dichroic filters at various incident angles. I apologize that it took so long to add this information, but our coating department needed to collect this data as the information was not on file. If you have any additional questions, please feel free to contact us.
cpontbriand  (posted 2008-09-02 11:48:51.0)
To Whom it may concern, I see that your dichroic filters have applications in imaging and illumination, but the stated angle of incidence is 0 degrees. There must be some tolerance about 0 degrees, given the stated applications. What sort of useable angle of incidence should I expect to get from these filters? Thank you, Clifford Pontbriand Engineer Woods Hole Oceanographic Institution

Ø1" Dichroic Filters (Unmounted)

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
FD1B Support Documentation
FD1BØ1" Additive Dichroic Color Filter, Blue
FD1G Support Documentation
FD1GØ1" Additive Dichroic Color Filter, Green
FD1R Support Documentation
FD1RØ1" Additive Dichroic Color Filter, Red
Lead Time
FD1C Support Documentation
FD1CØ1" Subtractive Dichroic Color Filter, Cyan
FD1M Support Documentation
FD1MØ1" Subtractive Dichroic Color Filter, Magenta
FD1Y Support Documentation
FD1YØ1" Subtractive Dichroic Color Filter, Yellow
7-10 Days

Dichroic Filter Set (Mounted)

The FD1D Dichroic Filter Set includes one of each of our Red, Green, and Blue Additive Filters as well as one of each of our Cyan, Magenta, and Yellow subtractive filters, each housed in an SM1-Compatible housing engraved with the part number.

Item #Included Filters
FD1DFD1R, FD1G, FD1B, FD1C, FD1M, and FD1Y
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
FD1D Support Documentation
FD1DDichroic Color Filter Kit, Complete Set of 6 Ø1" Filters
7-10 Days