Plate Beamsplitters for Laser and Imaging Systems

Did You Know?

Beam splitters find applications for interferometers, auto correlators, cameras, projectors and laser systems. There are plate, cube, pellicle and polka dot Beam splitters. The beam splitter adds to the growing catalog of devices being created for future photonic computing. A beam splitter that consists of a glass plate with a reflective dielectric coating on one side gives a phase shift of 0 or π, depending on the side from which it is incident. Transmitted waves have no phase shift. Reflected waves entering from the reflective side are phase-shifted by π, whereas reflected waves entering from the glass side have no phase shift. Standard beam splitters are designed to split incident light at a specific Reflection/Transmission (R/T) ratio that is independent of polarization state.
Read more in our Blog

Related Resources

Frequently Asked Questions

A plate beamsplitter is a flat, typically thin optical substrate with a partially reflective coating on one surface that divides an incident beam into reflected and transmitted components. Unlike cube beamsplitters, which use two right-angle prisms cemented together, plate beamsplitters introduce a slight physical offset between reflected and transmitted beams and can produce secondary reflections from the back surface unless that surface is wedged or AR-coated.

What Are Plate Beamsplitters?

Plate Beamsplitters are flat optical substrates with a partially reflective coating on one surface, designed to divide an incident beam into reflected and transmitted components. Unlike cube designs, Plate Beamsplitters minimize optical path length and absorption, making them suitable for compact setups and broadband operation. They are commonly used in interferometers, beam sampling, laser monitoring, imaging paths, and optical metrology.

Typical Specifications of Plate Beamsplitters

On FindLight you will find Plate Beamsplitters specified by substrate material (BK7, UV fused silica, float glass, IR materials), clear aperture, dimensions, and surface quality (e.g., 20-10 to 60-40 scratch-dig). Coating parameters include nominal split ratio (50:50, 30:70, 10:90, non-polarizing), wavelength range (UV, visible, NIR, MIR), and angle of incidence, typically 45° or 0°.

Additional data often provided are flatness (λ/10 to λ/2 at 632.8 nm), parallelism, reflectance and transmittance tolerances, and damage thresholds for CW and pulsed lasers. Many Plate Beamsplitters also specify polarization dependence, AR coating performance on the second surface, and spectral uniformity across the specified band.

Use Cases and Application Considerations

Plate Beamsplitters are used in laser alignment, Michelson and Mach-Zehnder interferometers, optical path sampling for power stabilization, fluorescence and imaging beam routing, and general lab beam diagnostics. For high-power lasers, buyers should consider substrates with high damage thresholds, low absorption coatings, and appropriate thermal properties. For broadband or ultrafast systems, low group delay dispersion and spectrally flat splitting are important.

Buyer Guidance on FindLight

When selecting Plate Beamsplitters on FindLight, compare the spectral range and split ratio against your source wavelengths and required power distribution. Verify angle of incidence, polarization sensitivity, and AR coating on the rear surface to control ghost reflections and fringe effects. Check surface quality, flatness, and substrate material to maintain wavefront quality and compatibility with your mounting scheme.

Use the platform to compare detailed specifications across multiple suppliers and to request quotes for custom Plate Beamsplitters or volume orders. All quote requests can be sent directly to vendors without registration, enabling fast evaluation of options for your optical system design or laboratory setup.