Products and Services

RSS

Optical Coatings at LASER COMPONENTS

Dielectric coatings have been manufactured in house at LASER COMPONENTS since 1986. The term laser optics covers everything from mirrors, lenses, and output couplers to polarizers used in laser systems. Thanks to new technology and skillful process control, both existing products can be improved and new innovative products manufactured. This article describes this new technology and what the advantages are to you.

Our in-house optics production site has a wide variety of coating technologies at its disposal. The most common method is known as physical vapor deposition (PVD) or e-beam. In this method, dielectric materials are evaporated using an electron beam in a vacuum. These (inexpensive) coatings feature a very high damage threshold, particularly at laser pulses in the nanosecond range.

Designed for use with the highest laser power achievable, we have ion-assisted deposition (IAD) coatings available. The coating chamber here is additionally equipped with a powerful ion source. The condensed layers are exposed to a jet of low-energy ions. The forming layers are very compact and do not exhibit a thermal drift.

Online Measurement of Coating Thickness
The demands made on high-quality coatings in the laser industry are continuously on the rise. To meet some of these demands, such as extremely high production precision and batch reproducibility, a broadband monitoring system for the optical in situ measurement of layer thickness was recently installed in the IAD coater.

In contrast to conventional testing methods, with in situ monitoring, the thickness of the deposited layer is measured directly on a substrate inside the chamber. A major advantage is that the entire visible optical spectrum is used to monitor the layer thickness.

The combination of ion-assisted coatings with the broadband monitoring of layer thickness leads to advantages when implementing complex coatings. Coatings with improved specifications can be implemented just as easily as new products.

Click Here To Download:
•Datasheet: Coating Processes

New Products
One example is the enhancement of the thin film polarizer (TFP), which is used at the Brewster angle of approximately 56°. While the p-polarized portion of the incident light is transmitted and experiences only a slight beam displacement, the s-polarized portion is reflected and experiences a deflection of approximately 112°. The idea is to achieve a high transmission Tp of the p portion and the highest possible extinction ratio Tp/Ts.

TFPB Broadband Polarizers
New thin-film polarizers were developed with the help of broadband monitoring. The broadband polarizers known as TFPB not only have a better extinction ratio but are also adjustment free. This means that they achieve an extinction ratio of more than 300:1 across the entire angular range from 54° to 58°. Even in slightly divergent or focused beams TFPBs can be used without suffering any losses.

Product Variations
There are two different variations available for this product. One possibility is to choose a specific wavelength. The polarizer can then be applied adjustment free within a certain angular range. Or, alternatively, one can forego the extended angular range and instead retain a precise angle of incidence. With this second alternative, the broadband polarizer can then be used for a wavelength range around the central wavelength. At a central wavelength of 532 nm, the interval is approximately 20 nm.

Furthermore, this coating is now also available for an angle of incidence of 45°, which is particularly advantageous for the user during assembly.
Click here for more information on Adjustment-free High Power Thin Film Polarizers.

Polarization-independent Beam Splitters
Another example of a new product is the polarization-independent beam splitter, which has the same degree of reflection for s-pol and p-pol light. Normally the user achieves different degrees of reflection for each polarization direction; however, with this new technology, polarization-independent beam splitters are now available at basically any wavelength.
Click here for more Information on Polarization-independent Beam Splitters.

What to Expect in the Future
Even now we are able to offer bandpasses, optical filters, and transmission and reflection gradients according to customer specifications. The broadband monitoring system makes it possible to manufacture a multitude of other complex coating designs. For example, very steep edges in short and long-pass mirrors can be produced. In dichroic mirrors a transmission of far above 95% can be achieved. The reflection values are over 99%. LASER COMPONENTS manufactures a variety of coatings to meet your specifications.
Click here for more information.