Gold Mirror, Economy, Borofloat, 50.8 mm Square, λ/10, 650-20,000 nm
The 20SD520ER.4 is an Economy Broadband Gold Square Mirror. By taking advantage of advanced polishing techniques and our high-volume manufacturing, these mirrors are truly cost effective. This 50.8 x 50.8 mm (2.0 x 2.0 inch) square mirror is made from 12.0 mm thick Borofloat® 33 substrate which is coated with the ER.4 gold coating. Borofloat® 33 has low thermal expansion and is an excellent substrate for most applications. The ER.4 protected gold coating is ideal for applications requiring broadband reflectance in the near IR to the far IR. A multilayer dielectric overcoat provides protection to the gold from the environment. The 20SD520ER.4 has an average reflectivity greater than 96% from 650–1700 nm and greater than 98% from 1.7–20 μm. This mirror has a λ/10 surface flatness and a 60-40 surface quality. Specifications
Wavelength Region
Broadband
Wavelength Range
650-20000 nm
Mirror Shape
Square
Mirror Size
50.8 x 50.8 mm
Thickness
12.7 mm
Material
Borofloat® 33
Coating Type
Protected Gold
Coating Code
ER.4
Surface Quality
60-40 scratch-dig
Surface Flatness
λ/10 at 632.8 nm
Angle of Incidence
0-15°
Clear Aperture
≥central 80% of diameter
Back Surface
Ground
Reflectivity
Ravg>96%, Rmin>92% @ 650-1700 nmRavg>98%, Rmin>96% @ 1.7-20 µm
Damage Threshold
0.5 J/cm², 10 ns pulses , 20 Hz at 1064 nm
Size Tolerance
+0/-0.13 mm
Thickness Tolerance
±0.25 mm
Chamfers
0.38-1.14 mm face width
Chamfers Angle Tolerance
45° ±15°
Cleaning
Wavelength Region
Broadband
Wavelength Range
650-20000 nm
Mirror Shape
Square
Mirror Size
50.8 x 50.8 mm
Thickness
12.7 mm
Material
Borofloat® 33
Coating Type
Protected Gold
Coating Code
ER.4
Surface Quality
60-40 scratch-dig
Surface Flatness
λ/10 at 632.8 nm
Angle of Incidence
0-15°
Clear Aperture
≥central 80% of diameter
Back Surface
Ground
Reflectivity
Ravg>96%, Rmin>92% @ 650-1700 nmRavg>98%, Rmin>96% @ 1.7-20 µm
Damage Threshold
0.5 J/cm², 10 ns pulses , 20 Hz at 1064 nm
Size Tolerance
+0/-0.13 mm
Thickness Tolerance
±0.25 mm
Chamfers
0.38-1.14 mm face width
Chamfers Angle Tolerance
45° ±15°
Cleaning