✅ Product Description

High density slot metal grating sheet for high-resolution applications.

Etched with precise control for consistent slot distribution.

Improves signal accuracy and detection sensitivity.

Durable metal structure with stable performance.

Supports customization of slot density and dimensions.

✅ Applications

High-resolution encoder systems

Precision positioning and motion control

Optical sensing and detection devices

Semiconductor inspection equipment

Industrial automation systems

Round, Square, or Slit? Aperture Shape Design for Optical Gratings

When engineering optical systems, the geometry of the aperture is just as critical as the material itself. The shape of the opening dictates how light passes through, how it diffracts, and ultimately, the quality of the signal received by the sensor.

At our factory, we specialize in manufacturing High Density Slot Metal Sheets with a wide variety of aperture geometries. Whether you need a simple linear slit or a complex array of micro-holes, understanding the optical implications of shape is key to optimizing your design.

The Physics of Shape: Diffraction and Light Throughput

Different aperture shapes interact with light in unique ways. Choosing the right shape involves balancing light throughput (how much light gets through) with diffraction effects (how the light spreads).

1. The Slit (Rectangular Aperture)
This is the most common shape for linear encoders and spectrometers.

• Optical Effect: A slit creates a one-dimensional diffraction pattern. The light spreads out perpendicular to the long axis of the slit.
• Application: Ideal for defining a line of light or for scanning applications. In a High Density Slot Metal Sheet, the aspect ratio (length vs. width) determines the resolution. A narrower slit provides higher resolution but reduces light intensity.

2. The Round Hole (Circular Aperture)

• Optical Effect: A circular aperture produces a radially symmetric diffraction pattern, known as an Airy disk (a central bright spot surrounded by concentric rings).
• Application: Best for point-source measurements or when the light needs to be focused onto a circular photodiode. It provides uniform resolution in all directions (X and Y axis).

3. The Square Aperture

• Optical Effect: Square holes produce a diffraction pattern that spreads out in a cross shape (perpendicular to the sides).
• Application: These are often used in pixel arrays or when maximizing the "fill factor" (packing density) is necessary. A square grid allows for more open area compared to a circular grid on the same pitch.

Manufacturing Capabilities: Beyond Standard Shapes

While traditional machining limits designers to simple lines or circles, our chemical etching process allows for complete geometric freedom. We can manufacture High Density Slot Metal Sheets with virtually any shape you can draw.

Complex and Hybrid Geometries:

• Trapezoidal Slots: Used for specific optical coding requirements.
• Fiducial Crosses: Integrated alignment markers etched directly into the sheet.
• Gradients: Slots that gradually change width or shape across the plate to modulate light transmission.

Precision Micro-Features:
Our process allows us to etch features with high accuracy. Whether you need a precision grating with 50-micron slots or a large aperture plate with complex mounting holes, we can achieve it without the burrs or stress associated with mechanical punching.

Comparison of Aperture Shapes

To help you decide which geometry suits your application, we have compared the characteristics of the three primary shapes:

Material and Surface Considerations

The shape is only one part of the equation. The material and surface finish of your High Density Slot Metal Sheet also play a vital role in optical performance.

• Stainless Steel (SUS304/316): The standard choice for durability and corrosion resistance.
• Nickel & Invar: Used for applications requiring low thermal expansion to maintain shape stability under temperature changes.
• Black Oxide Coating: We can apply blackening treatments to the metal surface to absorb stray light, preventing reflections from the "land" areas (the metal between the slots) from interfering with the signal.

Conclusion

From simple linear slits to complex arrays of round or square holes, the geometry of your aperture defines the performance of your optical system. Our factory combines the flexibility of digital tooling with the precision of chemical etching to produce High Density Slot Metal Sheets that meet exact optical specifications. Whether you need to minimize diffraction or maximize light throughput, we can manufacture the perfect shape for your application.

Contact Us for Optical Solutions
Need a custom aperture shape? Let us help you design and manufacture the perfect grating.
Contact: Luna
WhatsApp: 12132219094

Frequently Asked Questions (FAQ)

Q1: Can you mix different shapes on a single grating?

A: Yes. Because we use digital photoplots, we can easily combine slits, round holes, and fiducial markers on a single High Density Slot Metal Sheet without additional tooling costs.

Q2: What is the minimum size for a round hole or square aperture?

A: Generally, the minimum diameter or width should be equal to the material thickness to ensure clean etching. For thinner materials, we can achieve features as small as 0.05mm.

Q3: How does the shape affect the signal in an encoder?

A: Slits are preferred for linear encoders because they create a sharp light/dark transition in one direction. Round holes are better for rotary encoders or point sensors where radial symmetry is required.

Q4: Do you offer custom shapes for specific optical masks?

A: Absolutely. We can manufacture precision gratings and masks in any custom geometry, including triangles, hexagons, or irregular polygons, based on your CAD files.

Q5: Can you etch shapes on curved surfaces?

A: Our standard process is for flat sheets. However, we can perform light forming operations after etching if your design requires a slight bend or curve.