Beam Splitter Optics
Custom Optical Beamsplitters
Custom Beamsplitter Supplier and Manufacturer
While beamsplitter is a term that includes many different functions and types of optics, at their core, beamsplitters divide a single beam into two different optical paths. This split can be based on intensity (partial reflectors), wavelength (color filters), or polarization (polarizers). Regardless of their function, they come in two basic geometries: plates and cubes. Each has its own advantage/disadvantage in a particular application. PFG produces custom beamsplitter plates and cubes in the UV, visible, and MWIR for a wide variety of different industries.
Optical Beamsplitter Selection
PFG offers different types of beam splitters such as an extensive variety of plate beamsplitters from UV to MWIR in a wide selection of sizes, glass types, surface quality, and a polarization state. We use optical beamsplitters with unpolarized light sources, such as polychromatic. A light beam splitter is commonly used in applications where polarization state is not important. Ranging from neutral density to dichroic beam splitter coating technologies to bandpass, including both polarizing and non-polarizing beamsplitter, we can customize them. These beamsplitters can be applied to right angle prisms, wedge, Penta, or rhomboids and may be optically cemented or chemically contacted for improved laser damage threshold.
Dichroic beamsplitters can split incident light by wavelength. These range from laser beam combiners we design for laser wavelengths to broadband cols and hot mirrors for splitting visible and infrared light.
Plate Beam Splitters
Cube Beam Splitter
Laser Line Beam Splitter
Partial reflectors are designed to split a beam into two paths with different intensity levels. These reflectors can come in any splitting ratio (R/T), such as 95/5, 90/10, 80/20, and 50/50. The equal 50/50 beamsplitter is often used to split a beam into two beams of equal intensity.
The higher split ratio beamsplitters find an application in beam sampling. PFG routinely designs custom partial reflectors with any splitting ratio for use at any angle of incidence. These beamsplitters also come in polarizing and non-polarizing options and can be designed as plate or cube beamsplitters.
Color filters, despite their name, are not limited to visible color filtering. More generally, these beamsplitters are designed to split a common beam into different paths with different wavelength bands. They accomplish this by reflecting, or blocking, one or more wavelength ranges while transmitting others.
Color filters come in many different versions, depending on which wavelength band is being transmitted. Short-wave-pass (SWP) beamsplitters transmit the shorter wavelength bands of interest while blocking the longer wavelength bands. Likewise, long-wave-pass (LWP) beamsplitters transmit the longer wavelength bands of interest. If an inner band needs to be transmitted, a bandpass filter is used. Inversely, if an inner band needs to be reflected, a notch filter (or minus filter) is used. Color filters can also be used in a reverse application as a color combiner, which combines different beams of different wavelength ranges into one. PFG has the capability to custom design and produce a color filter to meet most any need. Our color filters have found use in many applications in the semiconductor and defense sectors. These can be designed for use at any angle of incidence and polarization state. Color filters may be designed as either plate beamsplitters or cube beamsplitters, depending on the application and specifications.
A polarizer is a type of beamsplitter designed to split a randomly polarized light beam into its two polarization states. Most often, polarizers are designed to transmit p-polarized light and reflect s-polarized light. Polarizers must be designed to be used at angle, usually either 45 deg or 56 deg angle of incidence.
Single wavelength polarizers can be done as either a plate or cube beamsplitter. Broadband polarizers, however, almost always must be done as a cube beamsplitter. PFG has designed and produced polarizing beamsplitters for all major laser-line wavelengths in the UV, visible, and SWIR. We also produce broadband cube beamsplitters for LED applications.
Because the polarization effects of a coating are enhanced when immersed inside glass, cube beamsplitters are useful for creating polarizing beamsplitters. Polarizers and broadband beamsplitters are much simpler and more cost-effective when done as a cube beamsplitter.
Some customers also find the general shape of a cube beamsplitter makes them easier to mount and align in their system. Some color filters, however, can be more difficult as a cube beamsplitter, due to the enhanced polarization effects, if the pass and blocking bands are too close together. Also, the cement layer of a cube limits its laser-induced damage threshold.
Plate beamsplitters have an advantage over cube beamsplitters due to their reduced size, weight, and complexity. Plate beamsplitters require the light to traverse much less glass than cube beamsplitters and don’t require a cement layer, which influences the laser-induced damage threshold of the beamsplitter.
Plate beamsplitters also have fewer faces that require coatings. For these reasons, plate beamsplitters are often chosen for simplicity, cost, and/or high laser damage threshold applications. Where plate beamsplitters are not as advantageous are in broadband and polarizing applications.
CUSTOM BEAMSPLITTERSOur sales and engineering team will review your optical drawing or custom specifications and provide an estimate. Typically, we offer:
3 to 400mm
15Ǻ with the ability to provide below 5Ǻ if requested
60/40 standard down to 10/5 Laser Quality (scratch/dig)
±0.05mm down to ±0.010mm
Center Thickness (CT):
±0.1mm down to ±0.025mm
±0.05mm down to ±0.010mm
Clear Aperture (CA):
85% down to 0.5mm or more from edge of finished optic
0.01mm ETD or 1 arc-minute deviation; 0.003mm ETD or 10 arc-seconds deviation
Optical Thin Film Coating Department Capabilities
- Specialize in producing custom coatings to meet customer specifications
- Electron Beam (E-Beam) and Ion-Assisted (IAD) coating process technologies
- Laser Line Coatings, Anti-Reflection, Highly Reflective, V-Coats, Broadband, Metallic, Polarizing, Non-Polarizing, Beamsplitters, Long-Pass Filters, and Short-Pass Filters
- Ultra-broadband AR’s available – covering visible and infrared (ex. 400nm – 2µm)