Pinhole arrays, spatial filters

Pinhole arrays and spatial filters are used for spatial filtering and act as virtual point light sources in many optical systems. In this case, a pinhole (pinhole aperture) limits the NA (divergence) and blocks larger angles. In laser applications, for example, adjusting the aperture diameter will hide (spatially filter) higher laser modes in order to improve the beam properties such as the focus.

In addition to elements to determine the wave front (Hartmann test), they are used in multi-emitter applications (e.g. VCSEL arrays) in order to separate the individual channels or as Nipkow discs (spinning discs) in confocal microscopy. Further applications include maskless lithography and endoscopy.

Substrate: Fused silica, B270, Borofloat, D263, other materials on request
Thickness: 0.3 mm–10 mm
Coating material: Chrome, IMTBC
Pinhole diameter: > 2 µm
Pinhole diameter tolerance: ±0.5 µm
Position accuracy: < ±0.5 µm
Optical density of the metal structure: > 3