Products Home / Optical Elements / Optical Mirrors / Concave Mirrors / Concave Mirrors: Visible Dielectric Coating (400 - 750 nm), Back Side PolishedConcave Mirrors: Visible Dielectric Coating (400 - 750 nm), Back Side Polished
- Focal Lengths from 12 - 100 mm
- Ø1/2" or Ø1" Sizes
- Dielectric Coating for 400 - 750 nm
- Back Sides Polished to λ/4 Flatness
CM127P-012-E02
Ø1/2''
CM254P-025-E02
Ø1''
CM254P-100-E02
Ø1''
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| Common Specifications | |
|---|---|
| Dielectric Coating Wavelength Range | 400 - 750 nm |
| Dielectric Coating Reflectance (0° to 45° AOI) |
Rs, avg, and Rp, avg, > 99% |
| Available Diameters | 1/2" and 1" |
| Clear Aperture | >90% of Diameter |
| Diameter Tolerance | +0.0 / -0.2 mm |
| Thickness Tolerance | ±0.2 mm |
| Substrate | N-BK7a |
| Front Surface Quality (Concave Side) | 20-10 Scratch-Dig |
| Front Surface Accuracy (Concave Side) | λ/4 at 633.0 nm |
| Back Surface (Plano Side) | Polished |
| Back Surface Quality (Plano Side) | 40-20 Scratch-Dig |
| Back Surface Flatness (Plano Side) | λ/4 at 633.0 nm |
| Dielectric Concave Mirrors Selection Guide | |||
|---|---|---|---|
| UV | 350 - 400 nm | ||
| Visible | 400 - 750 nm | 400 - 750 nm, Back Side Polished | |
| NIR | 750 - 1100 nm | 750 - 1100 nm, Back Side Polished | |
| Telecom | 1280 - 1600 nm | ||
See the Concave Mirror Guide tab, above, for our complete selection of concave mirrors.
Features
- High-Reflectance Dielectric Coating for 400 - 750 nm (-E02)
- >99% Average Reflectance Over Dielectric Coating Range
- Two Diameter Options: 1/2" and 1"
- Focal Lengths Range from 12 mm to 100 mm
- Polished Back Surface
- Surface Flatness: λ/4 at 633 nm
- Surface Quality: 40-20 Scratch-Dig
Thorlabs' Broadband Dielectric Concave Mirrors are designed for a wide variety of light collection, imaging, and focusing applications. These reflective optics focus light without chromatic aberration, making them especially suitable for broadband sources. With a surface accuracy of λ/4 at 633 nm, these mirrors provide excellent image quality.
Since the back sides are also polished to a λ/4 flatness at 633 nm with a surface quality of 40-20 scratch-dig, these mirrors will transmit a very small portion (<<1%) of the incident light within the coating band, thereby enabling sampling of the incident light without the need for additional optical elements.
Although the transmission properties of back side polished mirrors are desirable in certain applications, there are tradeoffs to consider. By polishing the back side of a mirror, more light will be reflected by the back surface, thereby increasing the number of stray beams present in the lab. When using back side polished mirrors, ensure that all stray beams are blocked appropriately. Thorlabs offers an extensive line of laboratory safety equipment (e.g., blackout materials, beam dumps, goggles) to facilitate safety precautions. In addition to safety concerns when using back side polished mirrors, unwanted interference effects can arise between the light reflected from the front surface and that reflected from the optically flat back surface. Finally, broadband dielectric mirrors are fabricated using a complex multilayer dielectric coating technique, which affects the transmitted light. Both the wavefront and the polarization of the transmitted beam will be altered, and these effects are temperature dependent.
All of the mirrors on this page can be mounted by our Precision Kinematic Mirror Mounts.
Thorlabs also offers Plano Back Side Polished Mirrors.
These plots show the reflectance of our -E02 dielectric coating for a typical coating run. The shaded region in each graph denotes the spectral range over which the coating is highly reflective. Due to variations in each run, this recommended spectral range is narrower than the actual range over which the optic will be highly reflective. If you have any concerns about the interpretation of this data, please contact Tech Support. For applications that require a mirror that bridges the spectral range between two dielectric coatings, please consider a metallic concave mirror.
Excel Spreadsheet with Raw Data for -E02 Coating, 8° and 45° AOI
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| Concave Mirrors Options | |
|---|---|
| Mirror Type | High-Reflectance Coating Wavelength |
| UV Enhanced Aluminum | 250 - 450 nm |
| Aluminum | 450 nm - 20 µm |
| Silver | 450 nm - 20 µm |
| Gold | 800 nm - 20 µm |
| E01 Dielectric | 350 - 400 nm |
| E02 Dielectric | 400 - 750 nm |
| E02 Dielectric, Back Side Polished | |
| E03 Dielectric | 750 - 1100 nm |
| E03 Dielectric, Back Side Polished | |
| E04 Dielectric | 1280 - 1600 nm |
| Crystalline | 1064 or 1550 nm |
Concave Mirror Selection Guide
Thorlabs offers concave mirrors with both metallic and dielectric stack reflective coatings. Metallic-coated mirrors offer relatively high reflectivity (90-95%) over a wide wavelength range, while dielectric-coated mirrors provide even higher reflectivity (>99%) but over a smaller wavelength range. See the table to the right for an overview of the various coatings we offer for our concave mirrors. All coating options are available on optics with diameters ranging from Ø1/2" to Ø75 mm. Metallic mirrors are available with focal lengths from 9.5 - 1000 mm, while dielectric mirrors are available with focal lengths from 12 - 1000 mm.
Below are reflectivity plots for our metallic- and dielectric-coated concave mirrors. To view our selection of mirrors available with a particular coating, either click on the graphed line of interest or the corresponding coating name in the legend. Graphs are shown for an angle of incidence (AOI) of 8 degrees, which is the recommended angle at which to use a concave mirror.
Click on a particular graphed line or the corresponding name in the legend to view concave mirrors with that coating option.
| Item # | Focal Length | Center Thickness | Edge Thickness | Radius of Curvature | Reference Drawing |
|---|---|---|---|---|---|
| CM127P-012-E02 | 12.0 mm | 3.0 mm | 3.8 mm | 24.0 mm (0.94") |  |
| CM127P-025-E02 | 25.0 mm | 3.4 mm | 50.0 mm (1.97") | ||
| CM127P-050-E02 | 50.0 mm | 3.2 mm | 100.0 mm (3.94") |
| Item # | Focal Length | Center Thickness | Edge Thickness | Radius of Curvature | Reference Drawing |
|---|---|---|---|---|---|
| CM254P-025-E02 | 25.0 mm | 6.0 mm | 7.6 mm | 50.0 mm (1.97") | |
| CM254P-050-E02 | 50.0 mm | 6.8 mm | 100.0 mm (3.94") | ||
| CM254P-075-E02 | 75.0 mm | 6.5 mm | 150.0 mm (5.91'') | ||
| CM254P-100-E02 | 100.0 mm | 6.4 mm | 200.0 mm (7.97'') |
VIS Dielectric Concave Mirrors, Back Side Polished