Transparent openings in an opaque chromium film define optical apertures without a hole through the glass. Specify aperture dimensions, spacing and transmission requirements.
Aperture-patterned glass uses transparent openings in an opaque film to define a transmitted field. The glass supports the openings without being pierced. Slits, circular apertures and arrays suit different beam, field and imaging tasks.
Choose a film-patterned aperture when the optical path can include a glass support and the instrument needs precisely located transparent windows within an opaque field.
These are transparent openings in a film on intact glass. A drilled aperture removes the glass as well. Slits select an elongated region, circular windows select a bounded area and small-hole arrays provide repeated bright features.
Opening size and shape, centre coordinates, spacing, field coverage and surrounding opaque area can be combined with mounting references.
A patterned glass component with the agreed coating geometry, substrate outline and inspection records.
| Opening geometry | Slit, circular aperture or aperture array |
|---|---|
| Clear and opaque regions | Coating openings with an intact glass support |
| Placement reference | Opening coordinates relative to mounting datums |
Inspect opening size, edge condition and position relative to the mounting datum. Define permitted leakage or defects in the opaque field at the operating wavelength.
The coating boundary defines the opening. It can restrict a viewing region or create a transmitted line or point pattern, depending on its location in the optical system. Aperture diameter and substrate diameter are separate dimensions.
Glass introduces wavelength-dependent transmission and surface reflections. In a converging beam, a plate can also change focus and aberration. Confirm thickness, orientation and any antireflection requirement with the optical design rather than treating a coated window as empty space.
A fluid path, unobstructed material passage or an optical system that cannot tolerate a substrate needs a different structure. Specify a mechanical through-hole separately. For small optical apertures, include diffraction in the system assessment as well as geometric diameter.
Choose the functional geometry first, then define its size, orientation and mounting relationship.
Glass-supported slit openings for spectrometer entrance fields, light shaping and optical alignment.
Repeated transparent circular openings for multi-point illumination, image registration and optical channel checks.
Circular clear windows in an opaque film for defining the transmitted beam and optical reference position.
| Control item | Information to confirm |
|---|---|
| Geometry and position |
|
| Substrate and optical path | Specify glass grade, thickness, wavelength and illumination side. Review transmission and reflections in the actual optical arrangement. |
| Inspection and acceptance | Inspect opening size, edge condition and position relative to the mounting datum. Define permitted leakage or defects in the opaque field at the operating wavelength. |
| Drawing and revision | Provide a 1:1 DWG with declared units, clear and opaque layers, viewing direction, active area and the approved revision. |
Compare slits, circular windows and point arrays.
No. The transparent openings are in the coating and the glass remains intact. A physical through-hole requires a separate machining specification.
Provide a DWG with units, film-side view, clear and opaque regions, opening dimensions, placement datums and the useful optical area.
Aperture-patterned glass forms transparent windows in an opaque film to control beam shape and optical field.
Specify aperture size and position relative to the optical and mounting axes, including the observation side and film plane.
Aperture geometry, coordinates, clear area, polarity, substrate, thickness and datums.
A film aperture transmits through the transparent glass underneath. A physical through-hole is a separate machining requirement.