• Nd-YAG-Laser-Plate-Beamsplitter

Nd: YAG Laser
Plate Beamsplitters

Beamsplitters are optical components used to split incident light at a designated ratio into two separate beams. Additionally beamsplitters can be used in reverse to combine two different beams into a single one. Standard beamsplitters are commonly used with unpolarized light sources such as natural or polychromatic, they split the beam by the percentage of intensity, such as 50% transmission and 50% reflection, or 30% transmission and 70% reflection. Non-polarizing beamsplitters are specifically controlled not to alter the S and P polarization states of the incoming light. Polarizing beamsplitters will transmit P polarization and reflect S polarization allowing the user to add polarized light into the optical system. Dichroic beamsplitters split incoming light by wavelength and are commonly used in fluorescence applications to separate the excitation and emission paths.

Beamsplitters are often classified according to their construction: cube or plate. Plate beamsplitters consist of a thin, flat glass plate that has been coated on the first surface of the substrate. Most plate beamsplitters feature an anti-reflection coating on the second surface to remove unwanted Fresnel reflections. Plate beamsplitters are often designed for a 45° AOI. Standard plate beamsplitters split incident light by a specified ratio that is independent of the light’s wavelength or polarization state, while polarizing plate beamsplitters are designed to treat S and P polarization states differently.

Paralight Optics offers plate beamsplitters with a coated front surface that determines the beam splitting ratio while the back surface is wedged and AR coated in order to minimize ghosting and interference effects. The Wedged plate Beamsplitters can be designed to make multiple attenuated copies of a single input beam. Our 50:50 Nd:YAG laser line plate beamsplitters provide splitting ratios of 50:50 at two wavelengths generated by Nd:YAG lasers, the 1064 nm and 532 nm.



Substrate Material:

RoHS Compliant, Exhibiting Virtually No Laser-Induced Fluorescence


Beamsplitter Coating on S1 (the front surface) for Nd:YAG Laser Wavelengths, Optimized for a 45° AOI; AR Coating Applied to S2 (the back surface)

Laser Damage Quantification Test:

High Damage Threshold

Custom Design:

Custom Design Available


Common Specifications:


Reference Drawing for

Nd:YAG Laser Plate Beamsplitter

Note: 30 arcmin wedged back surface on plate Beamsplitters Minimizes Ghosting.


Ranges & Tolerances

  • Substrate Material

    UV-Grade Fused Silica

  • Type

    Nd:YAG laser plate beamsplitter

  • Dimension Tolerance

    +0.00/-0.20 mm

  • Thickness Tolerance

    +/-0.20 mm

  • Surface Quality (Scratch-Dig)

    Typical: 60-40 | Precision: 40-20

  • Surface Flatness (Plano Side)

    < λ/4 @633 nm per 25mm

  • Overall Performance

    Tabs = 50% ± 5%, Rabs = 50% ± 5%, Tabs + Rabs > 99% (45° AOI)

  • Polarization Relationship

    |Ts - Tp| < 5% & |Rs - Rp| < 5% (45° AOI)

  • Wedge Angle Tolerance

    30 arcmin ± 10 arcmin

  • Chamfer

    Protected < 0.5mm X 45°

  • Split Ratio (R/T) Tolerance

    ±5% at specific polarization state

  • Clear Aperture

    > 90%

  • Coating (AOI=45°)

    S1: Partially reflective coating / S2: AR coating (Rabs < 0.5%)

  • Damage Threshold

    >5 J/cm2, 20ns, 20Hz, @1064nm



♦ Laser line plate beamsplitters especially for use with Nd:YAG wavelengths (1064 nm and 532 nm);
♦ The plots are the transmission curves for the 50:50 Nd:YAG plate beamsplitters showing that overall performance: Tabs = 50% ± 5% Rabs = 50% ± 5%, Tabs + Rabs > 99% for S- or P-pol. at 45° AOI.


50:50 P-Pol. Nd:YAG Laser Plate Beamsplitter @515-532nm at 45° AOI


50:50 S-Pol. Nd:YAG Laser Plate Beamsplitter @1028-1080nm at 45° AOI


50:50 P-Pol. Nd:YAG Laser Plate Beamsplitter @1028-1080nm at 45° AOI