wavelengths
 

Metal coatings

 

LASEROPTIK offers standard mirror coatings such as aluminium, gold or silver, normally with protection layer or even enhanced, i.e. with an additional dielectric coating system.

Reflectivities of metal coatings
Metal coatings have a fair but very broad reflectivity over a certain wavelength range.
Metal
Metal
λ [nm]Al-VUV
R >
Al-VIS-IR
R >
Ag
R >
Au
R >
120 65%      
157 65%      
193 70%      
220 75%      
300 80% 80%    
450   85% 95%  
532   88% 96%  
808   80% 97% 97%
940   87% 97% 97%
1064   92% 97% 97%
1550   92% 97% 98%
2940   92% 97% 97%

Al – Aluminium shows the highest reflectance in the UV. A reflection dip occurs around 850 nm due to phonon absorption. With a fluoride protection layer Al coatings can be optimized for use in the VUV.

Ag – Silver coatings give the highest reflectivity in the VIS and NIR. As they have low GDD in a broad wavelength area they can be taken as simple and low-priced mirrors for femtosecond lasers.

Au – Gold shows poor adhesion to glass and needs a bonding layer of chromium. It is often used in the far IR without a protection layer or as a solderable coating.

Other metal coatings are available too, e.g. chrome, chrome-nickel or platinum.

All values are given for standard coatings. Customized coatings available for all types.

Coating methods available:

EBEIAD
Al + Protection Layer - VIS-IR
[B-00018-01]Al + Protection Layer - VIS-IR

> 300 nm: R ± 3% vs. curve

Al enhanced 532 nm /45°
[B-08462]Al enhanced 532 nm /45°

532 nm: R > 97%

Ag + Protection Layer
[B-00931]Ag + Protection Layer

450-500 nm: R > 95%; 500-1100 nm: R > 97%

Ag enhanced HR 650-1350 nm for fs /45°
[B-10662-02]Ag enhanced HR 650-1350 nm for fs /45°

650-1350 nm: Ravg > 98%

Au + Protection Layer
[B-06039]Au + Protection Layer

IR: R > 97%

Metallic Filter T 20%
[B-02754]Metallic Filter T 20%

550 nm: T20 ± 3%