Protected + Enhanced Metallic Coatings (PAL / EAL / PAG / EAG / PAU / EAU)

Coating Code

Specifications

Average Reflectance (%)

PAL

Protected Aluminum Coating

87.0

EAL

Visible Enhanced Aluminum Coating

93.0

PAG

Protected Silver Coating

98.0

EAG

Enhanced Silver Coating

99.2

PAU

Protected Gold Coating

98.0

  • Broadband reflectors
  • Not sensitive to polarization and incident angle
  • Low damage threshold, can NOT be used on high power/energy lasers

Metallic coatings make very broad bandwidth reflectors. Usually it is best to protect the coatings with a durable dielectric layer as they are very soft and susceptible to scratching. The efficiency of metallic reflectors falls off at shorter wavelengths but this may be enhanced by the application of a multi-layer dielectric thin film stack. The table shows the reflectance of each of the metals without any protection or enhancement. Protected metallic coatings have a dielectric coating layer over the metallic layer to protect the coating from being oxidized in the air or from scratched. For enhanced metallic coatings, a stack of dielectric layers are added on the metallic coating to increase reflectance for a particular wavelength range.

Reflectance (%)

Wavelength λ (μm)

Al

Ag

Au

0.220

91.5

28.0

27.5

0.240

91.9

29.5

31.6

0.260

92.2

29.2

35.6

0.280

92.3

25.2

37.8

0.300

92.3

17.6

37.7

0.315

92.4

5.5

37.3

0.320

92.4

8.9

37.1

0.340

92.5

72.9

36.1

0.360

92.5

88.2

36.3

0.380

92.5

92.8

37.8

0.400

92.4

95.6

38.7

0.450

92.2

97.1

38.7

0.500

91.8

97.9

47.7

0.550

91.5

98.3

81.7

0.600

91.1

98.6

91.6

0.650

90.5

98.8

95.5

0.700

89.7

98.9

97.0

0.850

86.7

99.2

98.2

0.900

89.1

99.3

98.4

0.950

94.0

99.3

98.5

1.000

97.0

99.4

98.6

1.500

97.4

99.4

99.0

3.000

98.2

99.4

99.3

5.000

98.4

99.5

99.4

6.000

98.5

99.5

99.4

70.00

98.6

99.5

99.4

8.000

98.7

99.5

99.4

10.000

98.7

99.5

99.4

15.000

98.9

99.6

99.4

20.000

99.0

99.6

99.4

Other wavelengths are also available upon request.  Please specify. 

Contact us to find your solution.   714 327 0600