Chirped Mirrors
![](https://www.thorlabs.us/Images/GuideImages/3746_DispCompMirrorSet_5.jpg)
- Corrects Dispersion Caused by Optical Elements
- Low AOI Allows Multiple Reflections Between Mirrors
- R > 99% for Either 650 - 1050 nm or 700 - 1000 nm
DCMP175
53.0 mm x 12.0 mm, Designed for Multiphoton Microscopy
UMC10-15FS
Ø1", Compensates for
1.5 mm of Fused Silica
UMC05-15FS
Ø1/2", Compensates for
1.5 mm of Fused Silica
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![Dispersion-Compensating Mirror Setup](https://www.thorlabs.us/images/TabImages/Dispersion_Chirped_Mirror_Round_A1-350.jpg)
Click to Enlarge
An example setup consisting of two UMC10-15FS chirped mirrors in POLARIS-C1G mirror mounts. These mirrors are designed with >99.5% reflectance and a low 10° AOI to support multiple reflections.
Features
- Chirped Mirrors Designed for Dispersion Compensation:
- UMCx-15FS: Each Reflection Compensates for Group Delay (GD) of 1.5 mm of Fused Silica
- DCMP175: Large GD Compensates for Long Path Lengths in Multiphoton Microscopy
- High Reflectance and Low AOI Allow Multiple Reflections (See Drawing to the Right)
- Fused Silica Substrates
Thorlabs' Dispersion-Compensating Mirrors correct for the pulse broadening that occurs when ultrashort pulses propagate through an optical system. Ideal for use as dispersion management tools (e.g., precompensation), we offer them in two types: round mirrors that compensate for transmission through fused silica, the most common substrate for ultrafast optics; and rectangular mirrors designed for the long path lengths and optical substrates used in multiphoton microscopes.
Since a femtosecond laser pulse consists of many different wavelengths, pulse broadening (a lengthening of the temporal intensity profile) will occur when the pulse passes through a dielectric medium, like glass. This broadening is caused by the wavelength dependence of the refractive index of the optical components through which the light travels. In typical glass, shorter wavelengths have higher indices of refraction than longer wavelengths, causing shorter wavelengths to travel slower. These mirrors are specifically designed so that longer wavelengths experience larger group delay dispersion than shorter wavelengths, allowing the shorter wavelengths to "catch up" to the longer wavelengths.
The coatings on these mirrors are deposited onto the surface using ion beam sputtering (IBS). This highly repeatable and controllable technique results in durable thin film coatings with high damage thresholds.
For Thorlabs' full selection of optics for ultrafast applications, please see the Ultrafast Optics tab.
Specifications | |||
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Item # | UMC05-15FS | UMC10-15FS | DCMP175 |
Wavelength Range | 650 - 1050 nm | 700 - 1000 nm | |
Reflectance over Wavelength Rangea | Rabs > 99.5% over Wavelength Range | Ravg > 99% over Wavelength Range | |
Group Delay Dispersion (GDD) per Reflection | -54 fs2 at 800 nm | -175 fs2 at 800 nm | |
Size | Ø1/2" | Ø1" | 53.0 mm x 12.0 mm (2.09" x 0.47") |
Diameter Tolerance | +0.00 / -0.10 mm | N/A | |
Thickness | 6.35 mm (0.25") | 9.5 mm (0.37") | 12.0 mm (2.09") |
Thickness Tolerance | ±0.10 mm | ±0.20 mm | - |
Clear Aperture | >80% of Diameter | At Least 8 mm x 50 mm | |
Angle of Incidence (AOI) | 10° | 8° | |
Surface Flatnessb | λ/4 at 632.8 nm Over Clear Aperture | λ/10 Over Any Ø8 mm in the Clear Aperture | |
Surface Quality | 15-5 Scratch-Dig | 10-5 Scratch-Dig | |
Back Surface | Polished | - | |
Laser-Induced Damage Threshold | 0.07 J/cm2 (800 nm, 43.2 fs FWHM, S-Pol, 10 000 Pulses)c | 0.10 J/cm2 (800 nm, 100 fs) | |
Substrate | Fused Silica | ||
Parallelism | ≤3 arcmin | - |
The plots below give the theoretically calculated reflectance and group delay (GD) of these mirrors and represent the designed performance. The actual performance will vary from lot to lot within the specifications given in the Specs tab. The highlighted regions represent the specified wavelength range of the mirrors.
![LIDT Plot](https://www.thorlabs.us/images/TabImages/Chirped_Mirror_LIDT_G1-400.gif)
Click to Enlarge
The laser induced damage threshold (LIDT) value of an ultrafast optic is defined as the fluence (per pulse) that produces visible damage after a given number of pulses. These LIDT values were measured with 43.2 fs FWHM pulses at 800 nm that were s-polarized. LIDT values are not guaranteed in the ultrashort pulse regime. As such, they are provided as a service to customers.
Posted Comments: | |
Lukasz Piatkowski
 (posted 2023-10-09 10:27:14.27) Hi,
I'm looking for dispersion compensating optics to deal with dispersion in the range 600-700 nm in the laser pulses coming from a white light laser source (NKT Fianium). What is the reflectivity/dipsersion compensation characteristic of your DCMP175 in the mentioned range?
With best wishes,
Lukasz cdolbashian
 (posted 2023-10-20 10:37:27.0) Thank you for reaching out to us with this inquiry. Unfortunately, these mirrors are not meant to be used <650nm as this is outside the design wavelength range. The in-range performance can be found in the "graphs" tab above. In the case you do decide to use them within this range, you will likely experience inconsistent performance from unit to unit, due to the above design consideration. XinWei Yi
 (posted 2023-04-01 16:00:55.72) I want to know the group delay dispersion (GDD) curve of UMC10-15FS at zero Angle of incident. cdolbashian
 (posted 2023-04-26 10:01:00.0) Thank you for reaching out to us with this inquiry. Unfortunately we do not have such data to share. we would estimate a redshift of about 2% with respect to the values we have posted for the 10° AOI. Cheng Zong
 (posted 2022-03-18 13:30:38.39) Hi, I find the DCMP175 surface is dusty. How to clean it? Can I use methanol or acetone to clean it? ksosnowski
 (posted 2022-03-22 05:33:05.0) Hello Cheng, thanks for reaching out to Thorlabs. We recommend light dusting with clean, dry air first to remove the largest particles. If solvent is needed to wipe the surface, you can use acetone, methanol, or isopropanol to clean this as the chirped mirror pair is not cemented. We offer lens wipes MC-5 and cleaning accessories to aid in this as well. It may be slightly easier to avoid streaks with isopropanol, as it dries slightly slower allowing a slower, more even wiping motion. Hendrik Wrigge
 (posted 2021-12-08 08:31:59.49) Using the UMC10-15FS mirrors, I noticed a slight ellipticity in polarisation after my mirror compressor. The initial beam bevore the mirrors is strictly linear polarized.
Inside the compressor, I use 16 reflections on the UMC10-15FS.
Is this a standart behavior of your mirror or do you have any coment on this?
Thank you in advance cdolbashian
 (posted 2021-12-22 04:29:22.0) Thank you for contacting us here at Thorlabs. We have not characterized the reflection-induced-polarization states for these mirrors. Theoretically though, if your polarization state was not completely within, or orthogonal to, the incident plane, you may see a slight ellipticity in your reflected beam, especially after 16 bounces. Based on our discussion it seemed that there was a bit of misalignment between the incident plane and the direction of linear polarization (~.5deg). Correcting this error solved the problem which you were seeing. Thank you again for reaching out to us and allowing me to help you work through this problem. Audrius z
 (posted 2020-09-30 08:28:56.68) Hello, could please send me the GDD curve for these chirped mirrors?
Best YLohia
 (posted 2020-10-01 03:57:11.0) Hello, thank you for contacting Thorlabs. Which specific mirror are you referring to? One can calculate this from the raw group delay data (found on the Graphs tab) by taking the derivative. I have reached out to you directly to discuss this further. Ondrej Novak
 (posted 2019-10-11 17:48:54.953) Dear colleagues, could you please provide us with a graph of DCMP175 GDD compensation performance over different wavelength? Such curve would be extremely helpful. I am especially interested in wavelengths from 920nm to 1040nm. How much fs2 can be compensate per single bounce? Thank you.
Ondrej YLohia
 (posted 2019-10-22 10:12:15.0) Hello Ondrej, thank you for contacting Thorlabs. The GDD for the DCMP175 is nominally -175 fs^2 at 800 nm but it changes a little with wavelength and has fairly large oscillations. I have reached out to you directly with some GDD data that we have up to 1000 nm. The oscillations become very large outside the design range. That's typical for all dielectric coatings, not just these chirped mirrors. We do not recommend using these at >1000 nm. yuezhu
 (posted 2017-12-18 12:46:27.343) Can I use chirped mirrors in optical coherence tomography system?
How about https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=3242 ?
Which one is better? tfrisch
 (posted 2018-03-22 12:16:19.0) Hello, thank you for contacting Thorlabs. Chirped mirrors and dispersion compensating prisms are both used to adjust for chromatic dispersion. Which one is better suited for your application will depend on how you intend to use these. I will contact you directly about your application. dtorchin
 (posted 2017-12-06 18:32:00.957) Individual chirped mirrors have GD oscillations as a function of wavelength. Is DCMP175 sold as a pair whose oscillations cancel? llamb
 (posted 2018-03-01 08:12:47.0) Hello, thank you for contacting Thorlabs. DCMP175 is indeed sold as a pair of mirrors. The oscillations will not cancel, but each reflection will add to the Group Delay Dispersion. The mirrors can be adjusted to increase/decrease the number of reflections, thus increasing/decreasing the GDD as needed for the application. pedro.oliveira
 (posted 2017-10-24 18:52:36.55) Dear Sir/Madam,
I would like to have the data for the reflectance and the GD for DCMP175?
Many thanks,
Pedro Oliveira tfrisch
 (posted 2017-10-30 01:55:22.0) Hello, thank you for contacting Thorlabs. We will reach out to you directly with theoretical data in tabular form that can be used for your calculations. t.wills
 (posted 2017-01-27 05:41:00.78) Dear Thorlabs,
Do you have a number available for the GDD per reflection at 940nm? This would be the wavelength I need to use.
I am confused by the graph showing 'GD' versus wavelength - 'GD' appears to go positive at wavelengths >850nm, which means the mirror wouldn't work for pre-compensation (but I suspect I haven't understood the graph).
Many thanks,
Tom tfrisch
 (posted 2017-02-17 02:34:05.0) Hello, thank you for contacting Thorlabs. GD and GDD are related by a derivative. I will contact you directly with more details, but the zero of GD is chosen only as a reference. user
 (posted 2013-08-23 10:41:42.49) Is there a recommended maximum distance between the mirrors, a maximum incidence angle or a maximum number of reflexions to consider? Is there an app note or recommendations on using these? Thank you. jlow
 (posted 2013-08-29 13:18:00.0) Response from Jeremy at Thorlabs: The recommended maximum angle of incidence (AOI) is about 7°. The correct mirror distance depends on the number of bounces needed. Depending on the wavelength of the laser used, the tolerable AOI can be different as well. We have some plots (for s- and p-polarization) showing the evolution of the calculated GDD in the specified wavelength range as a function of AOI. As a general rule of thumb, the maximum AOI is smaller if the laser wavelength is longer. For example, around 20° AOI might be useable for 750-800nm light but around 10° AOI might be useable for 900-950nm light. However, it should be noted that the performance is not guaranteed for large AOIs. Since you did not leave your e-mail address, can you contact techsupport@thorlabs.com please? We can discuss about this further via e-mail. tcohen
 (posted 2012-05-16 13:45:00.0) Response from Tim at Thorlabs: Thank you for contacting us Jan Metje! Our baseline LIDT for the DCMP is 0.1J/cm^2 for 100fs pulses at 100Hz. Please note that for shorter pulses and higher repetition rates the damage threshold will be smaller. jan.metje
 (posted 2012-05-15 07:57:14.0) Dear Sir or Madam,
do you know the damage threshold of this dispersion comensating mirror set?
Kind regards,
Jan Metje bdada
 (posted 2011-10-12 19:22:00.0) Response from Buki at Thorlabs:
The DCMP175 Dispersion-Compensating Mirrors can be mounted in the KM100C Kinematic Cylindrical Lens Mount. The mount accepts any cylindrical or rectangular optic up to 65 mm tall.
The mount can be attached to any of Thorlabs' Ø1/2" TR Series posts, which feature an #8-32 (M4) tapped hole. Alternatively, the KM100C mount can also be attached to an RS1.5P Ø1" Pedestal Pillar Post, which has a height of 1.5", and can be secured to the breadboard using a CF125 Clamping Fork.
Alternatively, these mirrors can be mounted in the Kinematic Grating Mount Adapter,KGM20, KGM40, or KGM60 which is compatible with Ø1", front-loading, unthreaded mirror mounts.
Please contact TechSupport@thorlabs.com if you have further questions. zacarias.garcia
 (posted 2011-10-12 08:52:58.0) Could you please tell us how and where to install these mirrors ? |
Thorlabs offers a wide selection of optics optimized for use with femtosecond and picosecond laser pulses. Please see below for more information.
Low-GDD Mirrors | |||||
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355 - 445 nm | 460 - 590 nm | 700 - 930 nm | 970 - 1150 nm | 1400 - 1700 nm | 1760 - 2250 nm |
Dielectric Mirror | High-Power Mirrors for Picosecond Lasers |
Metallic Mirrors | Low-GDD Pump-Through Mirrors |
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Dual-Band Dielectric Mirror, 400 nm and 800 nm |
Ytterbium Laser Line Mirrors, 250 nm - 1080 nm |
Ultrafast-Enhanced Silver Mirrors, 750 - 1000 nm |
Protected Silver Mirrors, 450 nm - 20 µm |
Unprotected Gold Mirrors, 800 nm - 20 µm |
Pump-Through Mirrors, 1030 - 1080 nm and 940 - 980 nm |
Deterministic GDD Beamsplitters |
Low-GDD Harmonic Beamsplitters |
Low-GDD Polarizing Beamsplitters |
β-BBO Crystals | Dispersion-Compensating Optics | |
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Beamsplitters & Windows, 600 - 1500 nm or 1000 - 2000 nm |
Harmonic Beamsplitters, 400 nm and 800 nm or 500 nm and 1000 nm |
High-Power, Broadband, High Extinction Ratio Polarizers, 700 - 1300 nm | β-BBO Crystals for Second Harmonic Generation |
Dispersion-Compensating Mirrors, 650 - 1050 nm |
Dispersion-Compensating Prisms, 700 - 900 nm |
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- >99.5% Absolute Reflectance from 650 to 1050 nm
- Group Delay Dispersion (GDD) per Reflection: -1.5 mm of Fused Silica (-54 fs2 at 800 nm)
- Clear Aperture: >80% of Diameter
- 10° AOI
Thorlabs' UMC05-15FS and UMC10-15FS chirped mirrors feature >99.5% absolute reflectance over the 650 - 1050 nm wavelength range. The coating is engineered such that each reflection compensates for the dispersion introduced by 1.5 mm of fused silica over the entire range. The 10° AOI allows these mirrors to perform similarly for both s- and p-polarized light, and is ideal for a compact setup where multiple reflections are needed.
Mounting Options
The Ø1/2” mirror is 6.35 mm thick, while the Ø1” mirror is 9.5 mm thick. These mirrors can be mounted by any mirror mount that accepts these optic thicknesses. To maximize the clear edge, we recommend mounting the UMC105-15FS in a POLARIS-C05G glue-in mirror mount, which features a 180° clear edge, and the UMC10-15FS in a POLARIS-C1G glue-in mirror mount, which features a 252° clear edge.
![Back to Top Back to Top](https://www.thorlabs.us/images/arrow_Vert.gif)
![DCMP175 Mounting Options](https://www.thorlabs.us/images/TabImages/Dispersion_Compensating_Mirrors_A2-200.jpg)
Click to Enlarge
Single DCMP175 Mirror Mounted Using a Mount Adapter
- >99% Average Reflectance from 700 to 1000 nm
- Group Delay Dispersion (GDD) per Reflection: -175 fs2 at 800 nm
- Coated Surface Dimensions: 50 mm x 8 mm
- 8° AOI
- Designed for Pulses with Spectral Bandwidth >50 nm FWHM
- Sold in Packs of 2
The DCMP175 consists of a pair of rectangular optics with >99% average reflectance over the 700 - 1000 nm wavelength range. These mirrors are designed to integrate with multiphoton microscopy setups, which typically include long path lengths through highly dispersive glass. The 8° AOI allows these mirrors to perform similarly for both s- and p-polarized light, and is ideal for a compact setup where multiple reflections are needed.
Mounting Option
As shown in the figure to the right, these mirrors can be mounted in the Kinematic Grating Mount Adapter, which is compatible with Ø1", front-loading, unthreaded mirror mounts, such as our Polaris Ultrastable Kinematic Mirror Mount.