Knight Optical – the leading global supplier of custom-made optical components – has met a universal increased requirement for high-precision ultraviolet (UV) optical components for high-performing automated (and manual) UVC disinfection systems.
Ultraviolet (UV) light – and, more specifically, UVC light between 200 and 280nm – has been used for germicidal irradiation for decades, primarily in laboratories, medical facilities, and water treatment. Since the novel coronavirus, COVID-19, became a worldwide pandemic and as each new variant brings fresh concerns, there has been an augmented demand to make this technology more accessible.
Specifically for automated UVC disinfection systems, employment within public sector buildings – such as hospitals and other medical clinics – is rife. Often, manual cleaning alone in healthcare environments such as these is not enough to kill pathogens; therefore, UVC sterilisation and disinfection has been a time-efficient method of decontamination for some time. However, following the rapid spread of the virus, more and more medical environments have sought this technology and additional premises within the public realm are continuing to turn to this solution.
Amidst this widespread wave in need for UVC disinfection in newer establishments, Knight Optical has been working with leading manufacturers of these systems more closely and frequently than ever before. The leading optics specialist has witnessed that the golden thread that runs through the most high-performing systems is on-spec, Metrology-tested optical components.
Building UVC Systems
To produce a typical system, a UVC light source needs to be used that works within this 200 to 280nm range. Ordinarily, this would be a mercury lamp transmitting at 254nm. Yet, this wavelength poses its own risks to humans, as it penetrates through skin and eyes and damages human cells alongside any bacteria and viruses. However, research has shown that far-UVC wavelengths between 207 and 222nm still inactivate pathogens but do not penetrate deep enough into active skin layers1 to damage human cells. This means that there has been a shift in developing far-UVC sterilisation systems in recent years as they can be functioned safely by humans (for manually operated systems) and used in high-traffic areas. KrBr and KrCl excimer lamps would be used, rather than a mercury lamp, with operating wavelengths of 207nm and 222nm, respectively.
Choosing The Right Components
Both automated and manual UVC Sterilisation and Disinfection systems require optical components that transmit or reflect within these UVC and far-UVC wavelengths.
Here at Knight Optical, our vast portfolio of UV optics is assembled to do just that. Whether it’s Windows, Lenses, Domes or Optical Filters, we have a wide range of stock optics in various specifications (thicknesses, focal lengths, diameters etc.) to meet a spectrum of robot assisted and manual UVC applications. What’s more, if our stock range doesn’t quite meet your exact requirements, we also offer a custom-made option, enabling you to specify everything from the component’s material and project-specific size down to optical coatings and more.
The substrate of these optical components is essential, and there are limited options with high transmission within the UVC region.
The most common materials for both automated and manual UV applications are:
- UV Fused Silica (UVFS):is frequently used as it is cost effective to produce and very durable
- Calcium Fluoride (CaF2):has a wide transmission band from 130nm and transmits over 90% within the UVC waveband
- Magnesium Fluoride (MgF2):has very similar transmission properties to CaF2, but it is more durable and resistant to water. It is often used in vacuum ultraviolet (VUV) and UV applications, where it is cut in such a way as to minimise the birefringence it can exhibit.
- Sapphire (Al2O3):is highly durable, being the second hardest mineral after diamond. Its transmission is lower than that of CaF2 and MgF2 but still has a transmission above 80% at 200nm onwards.
Optical Filters for UVC Sterilisation and Disinfection Systems
Optical Filters, such as Bandpass and Shortpass varieties, are also vital components within these disinfection systems. For example, a Bandpass Filter can be designed to have a centre wavelength within the far-UVC whilst blocking above 230nm and, therefore, ensuring that any harmful UV light does not exit the system.
At Knight Optical, one of our main priorities is to supply ready-to-order Bandpass Filters that cover these specific wavelengths. What’s more, our stock catalogue now includes mounted Interference Bandpass Filters in 25 and 35mm diameters with centre wavelengths (CWLs) between 214 and 320nm.
Why Choose Knight Optical for your Application?
We test each optical component against its specification within our on-site, state-of-the-art Metrology Laboratory. The facility is equipped with a wide range of instruments to measure the different parameters on an optic.
- Zygo Verifire XPZ interferometer:for measuring surface form, such as irregularity, flatness, and transmitted wavefront distortion. We also use the interferometer for radial measurements on optical lenses.
- Trioptics OptiSpheric and OptiCentric:for radius, focal length, and centring error measurements
- Agilent Cary 7000 spectrophotometer: for spectral measurements, with the ability to check coatings at multiple angles of incidence and different polarisation states
Discerning customers rely on Knight Optical not only for the premium quality of our output and in-house state-of-the-art Metrology Laboratory and QA Department’s capabilities but because – as well as a range of Stock Optics (available for next-day dispatch) – we also offer our optics as Custom-Made Components.
Last year, we celebrated 30 years in business. With over three decades’ experience under our belt and a whole host of long-standing world-renowned customers on our books, we are proud to have worked on some of the most ground-breaking innovations.
If you are looking for premium-quality, bespoke optical components for UVC systems, please do not hesitate to get in touch with a member of the Technical Sales Team today.