Optical thin-film coatings are found in a myriad of end applications, from spectacles to fighter aircraft, and are one of the key enabling technologies of photonics, which in turn is a critical technological base for medicine, defence, telecommunications, space applications and future advanced computing.  Optical thin film coatings are considered as one of the major enabling technologies for innovation throughout science and engineering.  

Optical coatings rely on the optical interference effects from thin layers of dielectric materials and create colour and angle-sensitive effects.  Similar interference effects can be seen in everyday life, for example in the colourful reflections seen from soap bubbles or oil films on water.  The advent of vacuum coating techniques has meant that thin films can be deposited repeatably with accurate thickness tolerances onto a variety of substrate materials.  By making the individual layers comparable to the wavelength of incident light, thin films can be designed to create very specific optical effects, a routine example of which is to reduce the natural reflection from the glass used in spectacles. 

Helia Photonics has extensive experience in design and fabrication of precision optical coatings for a number of applications.  One specific area of expertise is the coating of semiconductor optoelectronic devices used in the spectral regions ranging from visible to mid-infrared. We specialize in high performance antireflection coatings for telecoms and datacoms devices either in mounted device form, individual bar, or jigs of many tens of bars and also high efficiency dielectric mirrors / couplers designed to meet individual requirements. The optical coating facilities are complemented by state-of-the-art scribe-and-break, pick-and-place and laser bar testing facilities.  Optical coatings at Helia are deposited by electron beam (EB) and thermal vapour (TV) with densification provided by ion assisted deposition (IAD).  The engineering of specialist coating jigs are provided locally by our sister company, Ritchie Precision, who have years of experience of dealing with precision vacuum-compatible tooling. 

Helia Photonics Ltd. offer innovative coating solutions across all aspects of the photonics industry. The company was established by industry experts in 2002 and is situated in purpose-built 8,000 ft² facility in the central belt of Scotland. Helia's engineering team has tackled a range of prototype and production challenges including:

• High damage threshold coatings for high power semiconductor pump lasers and arrays
• Ultra-low anti-reflection coatings for semiconductor laser facets
• Coatings for delicate optical crystals
• Ultra-low reflectivity coatings (less than 0.01%) on a variety of substrates
• Range of bandpass and dichroic filters in the ultra-violet, visible and infrared - suitable for biophotonics applications
• Cold plasma deposition on plastics
• Optical metallic coatings (Al, Ag, Rh, Cr, etc.)

The coating facility is located in a class 10K cleanroom fitted with HEPA laminar flow hoods and housed within a custom designed air conditioned building. All the supporting metrology exists within the cleanroom including digital inspection microscopes, spectrophotometers and physical and chemical test apparatus. A few steps away is the characterisation cleanroom, where the back-end processing of optoelectronic devices takes place..

Our current production designs run from a simple single layer AR to more complicated multi-layer bandpass filters - the result of our thin-film design expertise. All designs are currently tested to military specifications. with plans to include Telcordia specifications in the near future.