Choose zinc selenide (ZnSe) when the optic sits in a CO2 laser beam or has to transmit past about 14 µm. Choose zinc sulfide (ZnS) when the optic faces weather, sand, or rain, or when visible light and thermal infrared have to share one aperture.…

ZnSe is a standard transmissive material for CO2 laser lenses, windows and output couplers at 10.6 µm because its bulk absorption there is very low. Published data gives ZnSe a 0.6–21 µm transmission range, so one part can pass a red alignment beam and long-wave…

Two narrowband filters may both be described as “850 nm bandpass filters” or “1064 nm narrowband filters,” yet their manufacturing cost can differ substantially. The reason is that center wavelength alone does not define the difficulty of a narrowband filter. A filter becomes more demanding…

What is a beamsplitter and how does it work? A beamsplitter is an optical component that divides incident light into two main optical paths: one reflected and one transmitted. In many designs, this is achieved with a partially reflective optical coating deposited on a transparent…

Choose a Raman edge filter when you only need Stokes signal and you want to measure as close to the laser line as physically possible. Choose a notch filter when you need Stokes and anti-Stokes in the same acquisition, or when your excitation wavelength moves…

The choice between a metallic mirror and a dielectric mirror comes down to one trade: bandwidth versus reflectance. A metallic mirror reflects moderately well (roughly 90% to 98%) across an extremely wide spectral range and barely cares about angle of incidence. A dielectric mirror reflects…

Choosing a medical device optical filter manufacturer is not simply a matter of finding a filter with the correct nominal wavelength. The finished component must work with the device’s light source, detector, optical geometry, operating environment and mechanical assembly. Its performance must also be defined…

A LiDAR filter manufacturer should be evaluated on more than whether it can supply a filter centered near the laser wavelength. The filter must work with the actual source spectrum, receiver field of view, detector response, angle of incidence, environmental conditions and mechanical package. For…

When an optical system needs to transmit one wavelength range and suppress another, both interference filters and colored glass filters may appear to solve the same problem. They do not, however, control light in the same way. A colored glass filter primarily relies on wavelength-dependent…

The difference between IBS vs IAD optical coating comes down to how much kinetic energy the film-forming atoms carry when they land, and what that energy buys you. Ion beam sputtering (IBS) delivers sputtered atoms with several to tens of electronvolts, producing amorphous, essentially fully…

To specify the OD blocking range for a bandpass filter you need two independent numbers, not one: the depth of rejection, given as optical density (OD), and the wavelength interval over which that rejection is guaranteed. The interval is set by your system rather than…