Stacks of dielectric layers whose reflections interfere destructively at the design wavelength. An uncoated glass surface reflects about 4 percent; a V-coat for one wavelength brings that below 0.25 percent and often below 0.1, while broadband coatings average under 0.5 percent over a range. AR coatings raise throughput, prevent ghosts and etalon fringes and protect lasers from feedback, but they are usually the weakest point for laser damage.
Order the lenses with the 1064 V-coat, the broadband AR is 0.8 percent at our line and that's ghosts everywhere.
Also heard as
- antireflection coating
- AR
Related terms
Ghost
A weak stray beam from a back-surface reflection that travels off in an unexpected direction or focuses somewhere it should not.
Damage threshold
The maximum fluence or power density an optic can take before it is permanently damaged.
Etalon
A pair of parallel reflecting surfaces that transmits a comb of sharp frequency peaks, used to select or measure wavelengths.
Pickoff
An optic, usually an uncoated wedge, that samples a small fraction of a beam and sends it to a diagnostic.