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Pellicle Beamsplitter, 74.9 mm, 51.6 mm Clear, 375-2400 nm, Coated
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In Stock


  • Diameter
    74.9 mm
  • Antireflection Coating
    375-2400 nm
  • Material
    Polymer film membrane
  • Surface Quality
    40-20 scratch-dig
  • Angle of Incidence
    45 °
  • Durability
    Hygroscopic film, keep from high humidity
  • Clear Aperture
    51.6 mm
  • Damage Threshold
    2 W/cm2 CW, 1 J/cm2 with 10 nsec pulses, typical
  • Thickness
    5 µm
  • Thickness Tolerance
    ±0.06 fringes/mm
  • Operating Temperature Range
    -40 to 70 °C


Wide Wavelength Range

Model PBS-2 is uncoated for beam sampling applications. Model PBS-2C is coated for beam splitting applications.

Newport's Pellicle beamsplitters are coated and uncoated to be used across an extremely wide wavelength range from 375-2400nm. Average transmittance and reflectance across a range of wavelengths and incidence angles is shown. For any specific incidence angle, a ±5% sinusoidal oscillation is superimposed on the transmission and reflection graphs.

Eliminate Ghosts From Multiple Surface Reflections

Pellicle beamsplitters are ultra-lightweight components that virtually eliminate multiple reflections commonly associated with thicker glass beamsplitters. Pellicles are manufactured by stretching a 5 µm thick polymer membrane over a flat metal frame. The extreme thinness eliminates secondary reflections by making them coincident with the original beam. Multiple wavelength versatility is an added benefit of an ultra-thin reflective membrane.

Vibration Effects

The extreme thinness of pellicles provides many advantages in reducing losses and ghost images. However, the polymer membrane can resonate due to vibrations in the environment. Stiff posts or riser blocks should be used in mounting pellicles to an optical table. Applications subject to air currents or acoustical noise should use glass beamsplitters.

Interference Effects

Interference effects due to thin membranes should be considered when using pellicles, which act as low finesse interferometers. While the thin membranes are ideal for eliminating ghost images in incoherent white light applications, in monochromatic applications interference between the front and back surfaces can introduce unwanted fringes into a transmitted or reflected beam. Over any wavelength range and for a fixed incidence angle, a ±5% sinusoidal oscillation is superimposed on the spectral transmission and reflection graphs. The oscillation vary rapidly with small changes in incidence angle. When using pellicles to split beams spanning a range of angles, the oscillations will average out.