What's the difference between a dichroic filter and a beamsplitter?

Difference Between a Dichroic Filter and a Beamsplitter

Function: Designed to selectively pass light of a small range of colors while reflecting other colors.
Usage: Commonly used in fluorescence microscopy, projectors, and lighting systems.
Construction: Made by depositing many thin layers of dielectric material on a glass substrate. The specific layer structure determines the wavelengths that are reflected and transmitted.
Directionality: Has a specific orientation; the coated side must face the source of light for optimal performance.
Transmission and Reflection: Transmits light of certain wavelengths while reflecting others, based on the design.

Function: Designed to split incoming light into two separate beams, which can be equal or unequal in intensity.
Usage: Widely used in optical experiments, laser systems, and imaging applications.
Construction: Can be made of glass or other transparent materials, with a coating that partially reflects and transmits light.
Directionality: Generally non-directional, meaning it can be used in any orientation.
Transmission and Reflection: Splits incoming light into two paths, typically at a specific ratio like 50/50, but other ratios are also possible.

Feature	Dichroic Filter	Beamsplitter
Function	Selectively passes or reflects wavelengths	Splits light into two beams
Usage	Fluorescence microscopy, projectors	Optical experiments, laser systems
Construction	Dielectric layers on glass	Coated glass or transparent material
Directionality	Directional	Non-directional
Transmission/Reflection	Wavelength-specific	Ratio-specific (e.g., 50/50)