high

	High Reflection Coating is that the coating to maximize the reflection on a broad range of wavelength or specific wavelength region. Many applications require that a surface reflect a very high proportion of the incident light, or reflect a fixed intermediate amount. In other instance it is desirable to have a high reflectance of one wavelength and a low reflectance for another wavelength. All these types of coatings rely on reflection enhanced, or high reflection coatings to achieve these results. SPO offers a wide range of these coatings to cover this range of applications. these coatings are used on mirrors, beamsplitters, dichhroic mirrors and rejection filters.
	Metal Coatings These are used primarily for mirrors and are not classified as thin films in the strictest sense. They do not rely on the principles of interference but rather on the optical properties of the coating material itself. However, metal coatings are often overcoated with dielectric coatings to increase the reflectance over a desired range if wavelengths or angles of incidence. In these cases the metal coating is said to be enhanced. Following is the illustration of typical metal coatings. For your specific application Contact SPO.
	Aluminum is normally used for applications requirung high ultraviolet reflection combined with reasonable ruggedness and relatively low cost. It is normally provided with a silicon oxide or magnesium fluoride overcoat. The over coating provides a surface rugged enough for normal handling and cleaning, and it provides an effective seal which reduces aging effects in the aluminum film. It meets the requirement of MIL-C-13508C, which means that a reflection of 86% is guaranteed.

	Silver is used as a coating material when high reflection is required or when a higher reflectance than Aluminum coatings can provide is needed. When used as an internal reflector, a protective over-coating is applied to preserve the high reflection. Silver coating is especially useful in the near infrared with over 99% reflection, where aluminum shows a relatively poor performance as a mirror. in oder to match the over coating, aa wavelength needs to be specified. This is commonly used for demanding broad band reflectance applications including instrument mirrors, metal mirrors for military application.

	Gold Coatings are used when a high reflection is required over a wide spectral range that covers infrared. Values of 97-98% in the near infrared to 99.4% in the far inrfrared make gold coatings one of the best thermal shields. Because of the softness of bare gold dust has to be removed, a low- pressure air blower can be used. This coating meets the environmental requirements of MIL-M-13508 on glass and metal substrates. This design is used in many laser diode applications including scanning, sensing, and fiberoptic device.

	Dielectric high reflection coating High reflectance dielectric layers work on the same principles as dielectric AR Coatings. Quarterwave thicknesses of various materials are applied to the substrate to form a dielectric multilayer.

Standard Laser Mirror
For relatively low powered lasers such as HeNe and Argon, this tandard laser
mirror coating produces excellent mirrors. On fused silica, Zerodur or Pyrex
substrates it shows a reflection of 99.7% at normal incidences, 99.9% for
S-polarization at 45^o incidence and over 99% or P-polarization at 45^o incidence.

Coating

Wavelength(nm)	Line
325.0	HeCd
337.1	N2
441.6	HeCd
488-514.5	Argon
632.8	HeNe
780.10	Diode
800.0	Diode
830.0	Diode

Dye Laser Mirror
A special group of coatings has been designed at SPO suitable for dye lasers.
They feature a relatively broad band area of high reflection(>99%) arount center
wavelengths that can be specified in increments of 50nm.The bandwidths for 0o
and 45^o incidence, when the reflection is over 99%, is show in the table below.

These coatings are available on our fused silicda flat or concave mirror substrates.
Due to the E-beam evaporation of these dielectric materials, the coatings meet
the adhesion and durability requirements of MIL-C-675C.

Coating

Wavelength		Bandwidth
(nm)	0o(nm)	45o S-pol.(nm)	45o P-pol.(nm)
400	60	80	30
450	70	90	35
500	80	100	40
550	90	110	45
600	100	120	50
650	110	130	55
700	120	140	60
750	130	150	65
800	140	160	70
850	150	170	75

High Power Laser Mirror
SPO provides a group of coatings especially designed to withstand high
power laser energy. Power levels of 500MW/cm² for 10 nanosec pulse
at 20pps are guaranteed not to damage these coatings.
These coatings are available on our fused silica flat. At 0^oincidence the
reflection is guaranteed to be >99.7% with extremely low scattering and
absorption losses. S-polarized light will be reflected >99.9% while the
P- component shows >99% reflection at 45^o incidence.
Inherent to the dielectric materials used, High power laser mirror coatings
meet adhesion and durability requirements of MIL-C-675C.

Coatings

Wavelength(nm)	Line
2940	Er.YAG
1.320	YAG
1.315	IODINE
1064	YAG(1)
694.3	RUBY(1)
532.0	YAG(2)
354.7	YAG(3)
347.2	RUBY(2)
266.0	YAG(4)

For specific application and wavelengths of these High reflection coatings, contact SPO.