Demystifying Optical Filtering- How does it Really Work?

Optical filters have been around for a really long time now, it seems. The truth of the matter is that they are a relatively new technology but the rate at which they are advancing makes it possible to think that they have been in use for ages. The quality and types of optical filters that are available in the market today is just incredibly good. This is especially when you compare to the ‘ancestors’ of optical filters. There are many more manufacturers than before with the likes of Alluxa making great strides to develop the next generation of optical filters that there is today.

What is an optical filter?

It is interesting how there is a lot of talk about these things but only a handful of people know exactly what they are and what they do. Well, you would be excused if you do not know because it is not something that is used on a daily basis in homes. Basically, an optical filter is meant for the selective transmission or rejection of different wavelengths. There are some which are being developed such that they are able to reject a range of wavelengths.

These tools are very common in spectroscopy, fluorescence microscopy, machine vision inspections and clinical chemistry. They are also ideal for life science and imaging. Alluxa has made it their business to create premium-quality optical filters that are durable enough to withstand high optical densities while still performing at their best. It is hard to buy such quality of filters in the market. It is even harder if you are working with a very tight budget.

Categories of optical filters

There is a wide array of filters out there in the market including custom-made ones such as those offered by Alluxa. The choice that you select to work with is totally dependent on your personal preferences and needs. When you are looking for an optical filter though, you will find them broken down into two main categories. These are the absorptive filters and the dichroic. The difference between these two is not really in what they are able or not able to filter but rather how they do the filtering.

1. Absorptive filters

An absorptive filter blocks light on the foundation of the absorption properties of the glass substrate that is used. In simpler words, light that is blocked is not reflected off the filter but rather absorbed and contained within it. This is a fantastic option to work with in a situation where noise from unwanted light is an issue. Moreover, absorptive filters are not extremely angle-sensitive. It is able to maintain its absorption and transmission properties with a wide variety of incident angles.

2. Dichroic filters

These ones work in the opposite way. They reflect unwanted wavelengths and transmit the desired portion. Unlike the absorptive counterparts, these ones are extremely angle-sensitive. Still they are excellent in their work, you simply need to get the best quality.

Bottom line

Alluxa has ensured that its clients are able to receive the best of optical filters including custom ones. The best part of it all is that these filters are offered at extremely affordable rates. You will not have to break the bank in order to purchase an optical filter for whatever projects you are conducting. Get in touch with their experts to find out more about this technology and how it can help you.

Ultra Series Thin Films is the author of this article on Ultra Narrow Bandpass. Find more information, about Optical Filters here


Tags: , , , , ,