The optics uses for rotating optical scanners can be primarily categorized in the four following groups. Waterloo Optics can assist in picking the right optic for your needs.
Prismatic Polygonal Scanning Mirrors (Regular Polygons)
Prismatic polygonal scanning mirrors are characterized by their regular, symmetrical design. Each mirror facet is at the same angle with respect to the rotating axis, and is parallel to the rotating axis. Each facet is the same distance from the axis, and as a result is the same size. This type of mirror is widely used due to its cost-effectiveness and ease of manufacturing.
Advantages:
- Cost-Effective: Manufacturing prismatic polygons is less expensive because multiple mirror facets can be processed simultaneously.
- Uniform Scanning: The symmetrical design ensures consistent performance across all faces, minimizing errors and distortions.
- High Speed: These mirrors are more easily balanced, and generally can be more precisely balanced, making them ideal for applications requiring rapid scanning.
Pyramidal Polygonal Scanning Mirrors
Pyramidal polygonal scanning mirrors feature facets inclined at a specific angle (typically 45°) to the rotational axis. Each facet is inclined at the same angle, and is at the same distance from the rotating axis. Given the uniformity, they can be made highly balanced for high speed operation, but due to the angle of the facets they are generally more expensive to manufacture than a regular polygon.
Monogons
Monogons are scan mirrors with a single optical face centered on the rotational axis. This design is not a true polygon but is an important subset of the scan mirror family. Monogons have the capability to scan in a full 360 degree circle, for example when incident light is aligned to the rotational axis and the monogon facet is at 45 degrees with respect to the axis.
Advantages:
- High Precision: With only one reflective surface, alignment issues are minimized, leading to highly precise scans.
- Cost-Effective: The simplicity of the design often results in lower production costs.
Irregular Polygonal Scanning Mirrors
Irregular polygonal scanning mirrors have facets at various angles, creating an asymmetric design. This irregularity can be advantageous in certain scenarios, offering unique scanning capabilities but also introducing challenges.
Advantages:
- Customizable Scanning Patterns: The irregular faces allow for tailored scanning patterns, optimized for specific applications.
- Versatility: These mirrors can be designed to meet unique scanning requirements that regular polygons cannot address.
- Specialized Applications: Suitable for applications where unique scanning patterns or specific angular reflections are required.
Irregular polygons are typically higher cost, given the complexity of the geometry.
Conclusion
The choice of optics in rotating scanners is crucial for achieving the desired performance and precision. Understanding the advantages and applications of prismatic polygonal scanning mirrors, pyramidal polygonal scanning mirrors, monogons, and irregular polygonal scanning mirrors can help in selecting the optimal solution for specific needs. Whether working on high-speed industrial scanning or cutting-edge research, these diverse optical options provide the flexibility and capability required to excel in various projects.
Let Waterloo Optics assist in taking your product to the next level by choosing the right optical element and the right scanning configuration for your application.