TECH FOCUS: OPTICAL FILTERS


Filters in focus


A look at the commercial offerings of the main players in optical filter technology and equipment


O


ptical filters are used to selectively transmit or reject light of different


wavelengths. They can usually pass long wavelengths only (longpass), short wavelengths only (shortpass), or a band of wavelengths, blocking both longer and shorter wavelengths (bandpass). Types of optical filters include absorptive, interference and dichroic filters. They are used in applications such as optical imaging, photography, test and measurement, lighting and illumination, astronomy, as well as fluorescence applications such as fluorescence microscopy and fluorescence spectroscopy. Absorptive filters are simpler


filters that are generally used to absorb specific wavelengths of light. The more complex interference or dichroic filters, on the other hand, can comprise


multiple optical coatings with precise thicknesses designed to transmit the desired wavelength range and reflect unwanted wavelengths. The latter can be high-pass, low-pass, bandpass, or band-rejection filters. Advances in optical coatings


over the years have generated explicit applications, which, according to Verified Market Research’s latest report, are leading to an upward trend in the market. The company says the global optical filters market size was valued at $1.46bn in 2021 and is projected to reach $3.32bn by 2030, growing at a compound annual growth rate of 7.81% from 2022 to 2030. In particular, according to the


Global Optical Filters Market Size By Product (Coloured Optical Filter, Bandpass Optical Filter), By Application (Medical Equipment, Household Electronics), By Geographic Scope And Forecast report, the


Knight Optical FEATURED PRODUCT


Knight Optical offers a wide range of optical filters, each tailored to meet specific needs. Filters are crafted to transmit select wavelengths while blocking others through reflection or absorption. The effective- ness of transmission and attenuation varies with the filter type. Here are the filter types Knight Optical can provide:


Interference bandpass, Dichroic, Colour Glass, Wratten 2/Polyester, Neutral Density, Heat Control, IR Cut Here are its typical filter capabilities:


Types available: Interference, Dichroic, Polyester, Wratten 2, Colour Glass, Neutral Density, Dimensions, Interference: 12.5mm to 100mm diameter, Dichroic: 3mm to 400mm diameter, Wratten 2/ Polyester: 100mm x 300mm, Colour Glass: 3mm to 100mm diameter, Neutral Density: 5mm to 300mm+, Wavelengths*:175 to 3200nm+, Bandwidth*: 3nm to 100nm+ , Peak Transmission*: > 85%, Blocking*: < OD4, Surface Quality*: < 60/40, Mounting Options: Mounted or unmounted Its filter capabilities are continually growing. Contact its UK and US teams and experience true precision, quality and innovation.


Further information: www.knightoptical.com/custom/filters


Asia-Pacific market is expected to expand at a significant growth rate. It is likely that large construction projects to improve infrastructure, especially in


Indonesia, Vietnam and India, will boost demand for the optical filter in the construction industry market, which is currently predicted to become the most significant market for optical filters during the projected period.


Optical filters are used to selectively transmit or reject light of different wavelengths 32 Electro Optics March 2024


Commercial products Vendors that offer optical filters include Alluxa, an ISO 9001:2015 certified manufacturer of high- performance optical filters and thin-film coatings. Its Ultra Series of optical filters and thin-film coatings are rigorously tested to ensure the highest possible performance and quality for each filter type, and all are designed and specified to exceed the performance of any comparable optical filters on the market. The company’s series of ultra-narrow bandpass filters achieve greater than 90% transmission, along with sub-


www.electrooptics.com


Vladimir_Dresvyannikov/Shutterstock.com


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44