High-Performance Fluorescence Filters for PoC Quick Covid-19 Testing

Delta’s filters are designed for the latest of PoC instruments and are used in clinical applications in the biotech, biomedical, and drug discovery sectors.

Point of Care (PoC) instruments have various uses in medical diagnostics, including the detection of infectious diseases such as Covid-19. These types of tests only require a single drop of blood, saliva, or urine and can be performed by a General Practitioner within minutes. Many tests require absorbance or fluorescence detection methods, which all demand optical filters. The optical filter is one of the most important components of a PoC instrument. It is used to attenuate unwanted light and allow wanted light to pass through, so the choice of the correct optical filters helps to optimize the device performance.


Smaller PoC instruments are required in order to make the equipment easier to transport and could potentially open the door to wearable diagnostics in the future. The newer, smaller PoC instruments still must match, if not surpass, the quality of existing, larger instruments, and effective optical filters help to achieve this. PoC instruments require small optical filters, and these small filters previously presented a challenge of attaining this level of quality. However, technological development is now starting to realize the quality required for successful optical filters. The development of all-dielectric ultra-hard coatings for optical bandpass filters was hugely beneficial as the coatings are stable for over 20 years. These coatings also provide the highest level of spectral discrimination.


Delta Optical Thin Film A/S can supply small custom optical filters for PoC instruments, which come with specialized designs to reduce the effects of large angles found in PoC instruments and polarization splitting. Our ultra-hard coated filters are suitable for applications in varied environments, as they do not alter in performance over time or in different conditions. Using latest dicing equipment, the filters can be as small as 1.5x1.5 mm² with edge chips well below 50 µm. The filters are typically delivered diced to the final size on adhesive tape or in Gel-Paks that can be handled by pick-and-place machines. Our optical filters are all designed for the next generation of PoC instruments and they have been used in clinical applications in the biotech, biomedical, and drug discovery sectors.

More information


Delta Optical Thin Film A/S

Fremtidsvej 1
2970 Hørsholm

+45 70 70 71 46