Glass-supported slit openings for spectrometer entrance fields, light shaping and optical alignment.
A chrome-on-glass optical slit is a narrow transparent opening in an opaque film supported by glass. It defines a strip of admitted light for spectrometers, illumination shaping and optical alignment.
Choose a glass-supported slit when the optical system can accept the substrate in the beam path and needs a stable, precisely positioned opening. Select substrate transmission for the actual wavelength.
The transparent slit passes light through intact glass. A metal foil slit has a physical opening with no glass beneath it. Their spectral transmission, reflections, mounting and handling requirements differ.
Slit width, length, number, spacing and orientation define the transmitted field. Film opacity, edge geometry and substrate thickness affect the light delivered to the instrument.
A patterned glass slit component. The spectrometer housing, slit adjustment mechanism and detector are separate parts of the instrument assembly.
| Slit geometry | Clear width, useful length and edge conditions |
|---|---|
| Placement | Centre, angle and mounting reference |
| Array relationships | Spacing and crossings where applicable |
Check width at defined positions along the slit, edge straightness, length and placement. Evaluate clear-window contamination and unwanted film pinholes separately.
| Configuration | Useful for | Selection detail |
|---|---|---|
| Single slit | One admitted strip of light | Specify width and length separately |
| Multiple slits | Repeated channels or geometric references | Control pitch and relative orientation |
| Metal through-slit | A physically open beam path | Different substrate, support and spectral behaviour |
In a spectrometer, narrowing the entrance slit can reduce the slit image width but also reduces admitted light. Spectral resolution still depends on dispersion, imaging aberrations, diffraction and detector sampling. A slit width alone cannot specify a wavelength resolution.
Slit length sets the accepted extent perpendicular to its width. Longer openings may admit more spatial information or light, but also expose off-axis aberrations and illumination non-uniformity. Match the length to the useful optical field.
Glass introduces wavelength-dependent transmission and surface reflections. Placing it in a converging beam can also alter the focus. Film-side location determines where the aperture plane lies relative to the mounting face.
| 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 | Check width at defined positions along the slit, edge straightness, length and placement. Evaluate clear-window contamination and unwanted film pinholes separately. |
| Drawing and revision | Provide a 1:1 DWG with declared units, clear and opaque layers, viewing direction, active area and the approved revision. |
Narrow transmitted-light regions on a glass support.
No. This product uses a transparent opening in the coating while retaining the glass support. A physical through-slot is a different construction.
Only until other optical and sampling limits dominate. Reduced light can worsen noise or require longer integration.
Both clear-region transmission and blocked-region leakage depend on wavelength. Visible appearance does not establish UV or infrared performance.
Chrome-on-glass optical slits leave a narrow transmitting region in an opaque film to select an optical field or form a line of light.
Define slit width, length and location independently of glass thickness. Set the film face and mounting datums for the optical path.
Slit width and length, straightness or position requirements, substrate, thickness, polarity and datums.
Slit width is the transparent width in the film plane. Substrate thickness is a separate glass dimension.