Metal coatings
Metal coatings have a fair but very broad reflectivity over a certain wavelength range.
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.
- HR
- DHR
- BBHR
- MHR
- WHR
- 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:
Examples
If not mentioned otherwise, all values and diagrams are given
... for the standard substrate material used in the described wavelength area (mostly Fused Silica or CaF2).
... without consideration of the rear surface.
... with EBE coating technique for a good cost-performance ratio.
Customized coatings are available for all types.
–––– dashed lines show the zoomed curve with the stated magnification
Every coating type can be optimized
for every
• substrate material
• wavelength
• reflection/transmis-
sion value
• angle of incidence
• polarization
• GDD value
• ...
Alternatively we can create
a totally new design for you.
