Epoxy-free bonding made simple

Precision Photonics CADB Epoxy Free Bonding

Micro-optic systems, consisting of prisms, beamsplitters and other optical components, are bonded together. The quality of these bonds is judged on their precision, mechanical strength, optical properties (eg scattering, absorption, index mismatch and power handling), thermal properties and chemical properties, as well as the simplicity of the process itself.

One of the commonest ways of bonding two pieces of optical glass is epoxy bonding. This is a reliable method, but, because it leaves a thick film, it is inappropriate for applications requiring precision thickness control. Other problems encountered include scattering, loss, movement and poor heat and UV resistance. So, there has long been interest in epoxy-free bonding. Traditional epoxy-free methods have included optical contacting, frit bonding and diffusion bonding.

CADB supplied by Acal BFi

Precision Photonics, one of the leading manufacturers who Acal BFi work closely with, have devised an epoxy-free system called CADB (chemically activated direct bonding). CADB is a gentler process than diffusion bonding, operating at much lower temperatures. It is also much more durable than optical contacting, resulting in robust, stable components that can be further polished or coated, even after assembly.

CADB is strong. It offers bond strengths often equal to the strength of the bulk materials being bonded. It is especially useful in high-power solid state laser assemblies used in:

  • medical instrumentation
  • materials processing, and
  • LIDAR (light detection and ranging).

CADB results in epoxy-free optical paths that are 100% optically transparent with negligible scattering and absorptive losses at the interfaces. It offers bonding that is exceptionally durable, reliable and resistant to temperature and humidity.

It can be used to produce high-energy laser optics and solid state laser components such as polarising beamsplitter cubes, microchip lasers and wave plates. In CADB, the parts are polished and physical and chemical contaminants removed.

CADB has been used in composite bonding of dissimilar materials. It can bond crystal, glass and ceramic materials and can be used over large areas (up to 200mm x 50mm) for high-volume applications, even on ion-beam-sputtered and ion-assisted dielectric thin films.

Custom shapes and sizes, limited only by the engineer’s imagination

Micrometals and Acal BFi. Micrometals are one of the world leaders in the production of high quality, low-cost iron-powder cores - offering an unrivalled customisation service.

read more

Finding the solution to challenging high-frequency requirements with established materials

Discover how your magnetic component designs and applications can benefit from carbonyl iron powder - Using a tried-and-tested material from a different sector.

read more

We put the power in your industrial application

Our portfolio covers every possible power supply scenario. From creating your own bespoke power supply with SynQor bricks, to flexible, user-configurable modular products from Excelsys, internal open-frame designs from SL Power to cost-effective, plug-and-play external supplies from Cincon, we put the power in your industrial application.

read more