About us

About us

Since more than 25 years quality directly from the specialist

The bk Interferenzoptik Elektronik GmbH was founded in 1991 for the production of  thin films, especially interference filters.
Ever since our products have been produced by  most modern, computer controlled high vacuum coating- and sputter plants.

The strategic orientation on innovative products is the basis for the success of our business.

We aren't only offering standard products, you also can get custom-made products, especially made for your requirements. We produce large series as well as small series (1 piece up).


Due to many years of experience in research, development and production of high quality optical filters we are constantly improving  our products.

Therefore our  company is worldwide acknowledged for its standard- and special coatings. Especially advantageous for our business proved the cooperation with Professor Dr. Stefan Sotier, which has been existing since the foundation of the company.

Constant high quality

"Quality is the totality of all characteristics of a product or service, which make it suitable to meet the requirements of the customers."

A crew of most qualified specialists as well as progressive ways of  production and efficient business organization guarantee constant quality standards (as required by DIN EN ISO 9001, MIL STD 810 E).

Short delivery terms

Short delivery terms even for large quantities (for standard filters as well as custom-made production).

In short – Why to choose us:

  • For us quality and safety always come first
  • Decades of experience
  • We put our customers' requirements into practice as partners
  • Our products and services are in accordance with made agreements
  • For environmental protection we focus on recycling and environmental-friendly usage of resources
  • The realization of our goals is based on our quality-manual, which is constantly being further developed to attend special requirements of our customers and our zero-defects-philosophy.