Exploiting extreme performance optical coatings developed within the UK gravitational wave community

Thin film coatings are core components within the majority of the technology that surrounds us, typically providing optical, electronic and/or protective/decorative functionality. Thin films are a key enabling technology within numerous vital sectors, including optical devices, telecommunications, energy and energy storage, functional/durable materials, biomedical, etc. Many commercial applications have helped drive the development of thin film coatings. For example, ion beam deposition (IBD) was originally developed for fabricating multilayer reflectors for laser ring gyroscopes, and then later exploited within the telecoms industry. The precision and uniformity of these coatings enabled the telecoms industry in the 1970s to fabricate DWDM (dense wavelength division multiplexing) filters, allowing transmission (and subsequent separation) of multiple optical signals at nearby wavelengths. Although IBD has typically remained the method of choice for the most demanding optical applications, the cost associated with the technology means that UK companies have to source from overseas companies. We note that the UK has a large number of companies that procure high-performance IBD coatings, within sectors such as defence, biomedical, laser engineering, and quantum technology. We also note that the UK plays a leading role in a number of large European and international science projects, which require enhanced performance IBD coating technology, including ELI (Extreme Light Infrastructure) and in gravitational wave detection (LIGO and the Einstein Telescope). The University of Strathclyde has pioneered electron cyclotron resonance (ECR) ion beam deposition, which can surpass the performance of current state-of-the-art ion beam deposition. This technology also has the ability to reduce associated costs, due to having core components which are maintenance-free (unlike current RF ion beam deposition). This project seeks to transfer this technology to a leading international supplier of photonic and optoelectronic devices, to enable the UK to be the international go-to-supplier of extreme performance optical coatings for next generation optical and quantum technologies.