Introduction - Optical Breadboard and Optical Tables Tutorial
When securing optical components in research, manufacturing, and field environments, optical tables and optical breadboards are critical components. Typically, tables and breadboards provide a rigid platform tapped with 1/4-20 or M6 holes on 1 inch or 25mm spacing. The first decision that must be made when purchasing an optical breadboard or table is what kind of rigidity or isolation from vibration is needed. In many cases, the incredibly versatile solid aluminum optical breadboard will do the job. In other cases, a larger more rigid structure such as a honeycomb optical table or breadboard is needed. Base Lab Tools offers both.
Honeycomb or Solid?
RULE OF THUMB - The thicker the breadboard, the more rigid (less deflection)
While the units in this graph are arbitrary and relate to only the particular setup, it's important to note the trend this information shows. The honeycomb deflects 1/3 as much as the same size 1/2 in. solid aluminum breadboard. The trend only improves when the thickness is increased to 4 inches, 8 inches, or more. Likewise, there is a rigidity gain when increasing from a 1/2 in. solid aluminum breadboard to a 3/4 in. solid aluminum breadboard.
Solid Aluminum Optical Breadboards
The Solid Aluminum Optical Breadboards (SAB-Series) is a nonmagnetic, general purpose mount surface used in a wide variety of applications. Other names for Solid Aluminum Optical Breadboards are Breadboard, Bench Plate, Optical Table, Tool Plate, Baseplate, Table Top, and Optical Platform. Solid aluminum optical breadboards come in a variety of standard, off the shelf shapes and are a convenient and cost-effective platform for prototyping optical assemblies, conducting experiments, mounting small subsystems, and stacking instrumentation. This type of breadboard is often used to increase available work space by allowing an optical setup to expand vertically over several levels.
Base Lab Tools offers standard solid aluminum optical breadboards made from precision-machined aluminum plates featuring a regular tapped hole-pattern and a low-reflective, matte black anodized finish. The hole pattern is tapped ¼-20 with 1 in. spacing or M6 with 25mm spacing to accommodate for easy mounting of components on the surface.
Base Lab Tools builds more sizes of standard aluminum breadboards than many other manufacturers, with stock sizes as large as 48 inches x 48 inches, but manufacturing even larger sizes upon request.
While the industry standard lead-time for custom work is 8 weeks or more, many labs prefer a custom solid aluminum breadboard rather than trying to build around a stock product. Base Lab Tools specializes in custom optical breadboards and tables, producing most custom products, fully anodized, in 2 weeks.
|Standard - 1/4-20 (M6) Tapped Holes - 1/2 in. (13mm) thick - Black Anodized - MADE IN USA|
|Thick - 1/4-20 (M6) Tapped Holes - 3/4 in. (20mm) thick - Black Anodized - MADE IN USA|
|Slim - 1/4-20 Tapped Holes - 1/4 in. (7mm) thick - Black Anodized - MADE IN USA|
|Double Density - Double 1/4-20 Hole Pattern - Black Anodized - MADE IN USA|
|Water Cooled - Plumbed for cooling - Black Anodized - MADE IN USA|
|Round - 1/4-20 Tapped Holes - 1 in. Centers - Black Anodized - MADE IN USA|
|Custom Solid Aluminum Breadboards - 2 Weeks - MADE IN USA|
6061-T6 is the preferred aluminum for solid aluminum breadboards in most applications. It is characterized by high tensile strength (42,000 psi (300 MPa)), high durability (HRB 60), and moderate difficulty of machining. It should be noted that the good mechanical properties of 6061-T6 have been achieved by tempering the aluminum in accordance with the T6 process of solution heat-treated and then artificially aging. For high temperature application other aluminum alloys should be considered e.g 2219. Additionally, in high temperature applications the choice of surface treatment should be reconsidered since the organic dye used in the anodize process will change color and typically fade away.
In vacuum application, not only the material and surface treatment should be considered, but also the cleanness and the total surface area of the solid aluminum optical breadboard. Therefore, we recommend a custom made breadboard to ensure that it fits your vacuum application. The breadboard requirements for 25C and 1E-3 torr and 400C and 1E-6 torr vacuum applications are quite different. Note that all breadboards need to go through a final cleaning on site before being put into a vacuum chamber/system.
Sizes, Is Bigger Better?
The rule of thumb is to use as small a breadboard as possible for maximum rigidity assuming fixed thickness for all sizes. Base Lab Tools offers ½ inch thick breadboards in sizes ranging from 6 in. x 6 in. to 48 in. x 48 inches in both rectangular and square shapes. If more space is required than initially anticipated it is easy to stack and join the optical breadboards from Base Lab Tools since the threaded mounting holes have an offset of ½ inch from the edge, allowing for a continuation of the hole pattern to the additional breadboard.
Solid aluminum optical breadboards are designed to mount on tables or other platforms. Base Lab Tools offers 5 counter-bore clearance holes on ALL breadboards for easy mounting and to enable single post mounting. Single post mounting prevents the transferring torsion to the breadboard from the mounting surface. The single post (one post) mounting is recommended for smaller, lower weight set ups. On larger setups, the use of all 5 mounting holes is highly recommended to increase stability and to minimize the deformation of the breadboard due to the load. A distinguishing characteristic of Base Lab Tools breadboards is the 5th mounting hole. Most of our competitors neglect to add the fifth hole on smaller breadboards where it is actually most convenient to have it.
Breadboard holes are threaded completely through allowing components can be mounted on both sides at once. To elevate the breadboard off the work surface a set of standoff posts are used to mount at various heights above the surface of a table (or breadboard) for a multi-level set-up. When choosing posts, make sure the plane that the posts are forming is flat to avoid bending the Breadboard during the mounting procedure.
The standard hole pattern of these breadboards make them easy to adopt and retrofit into existing work station environments.
Solid aluminum breadboards typically have four mounting holes located at each corner of the surface. This geometry has a significant drawback when the load on the breadboard is uneven leaving it susceptible to bowing and deformation. To mitigate the problem with bowing Base Lab Tools has added a fifth mounting hole in the center on ALL optical breadboards. The fifth mounting hole also allows for single post mounting. To efficiently mount an optical breadboard, counterbored mounting holes should be used, allowing the user to place components over the full surface without interference for the head of the mounting screws. To further improve the usability, offset mounting holes in combination with the first row of holes is less than ½ in. (or 12.5mm) offset from the edge, allowing for joining of two breadboards while maintaining a full, uninterrupted, threaded hole matrix.
Metric optical breadboards are normally tapped M6 with a 25mm hole spacing while US/Imperial versions are tapped ¼-20 with a 1 inch spacing as shown in this article.
The mounting holes may be used to attach the breadboards to optical tables, other breadboards, mounting posts, brackets, and a variety of other mounts.
Solid Aluminum Optical Breadboard has no built in vibration damping besides the material properties of the aluminum plate. Therefore external vibration damping may be needed, e.g. by using vibration damping mounting feet. Note that the choice of damping feet heavily depends on the load thus you will need to estimate the load prior to building your set up. By mounting the breadboard on a vibration damped optical table additional damping may not be necessary.
Note that there is no single vibration damping system that is best for all applications.
Solid aluminum optical breadboards are nonmagnetic general purpose mounting surfaces used in a wide variety of applications. Solid aluminum breadboards come in a variety of standard, off the shelf shapes and are a convenient and cost-effective platform for assembling prototype optical assemblies, conducting experiments, mounting small subsystems, and stacking instrumentation.
The key mechanical property besides material properties is the flatness of the optical breadboard. The flatness requirement depends on the mounting technique and the size of the mounting surface. In general, the flatter the surface, the better and easier it is to use.
Flatness of a good solid aluminum optical breadboard is typically better than ±0.005"/ft
The optical properties of solid aluminum breadboards are normally not important. Still, the solid aluminum optical breadboards have a matte black finish to minimize unwanted reflection in the visible spectrum. Note however, parts that look black in the visible spectrum do not automatically appear “black” in the UV or the Infrared. Also, the angle of incidence of the light will have an effect on the reflectivity. It is not recommended to use breadboards as beam dumps even though they look black to the eye.
Exposure to UV-light may change the color of solid aluminum breadboards but does not generally change the performance.
Solid aluminum optical breadboards are compatible with a large set of accessories that includes
Enclosures, light and/or dust tight
Lab jacks for height adjustment
Base Lab Tools provides custom configurations and accessories to meet special application needs including custom shape, custom hole patterns e.g. double-hole density and alternative materials e.g. Steel.