Optimized Damping

Broadband Damping
The most important feature of an optical table or breadboard is its resonant frequency. Since resonant frequency and vibration amplitude are inversely related, the resonant frequency should be as high as possible to minimize vibration intensity. Nexus tables and breadboards are broadband damped over a specific range of frequencies. For improved performance, the damping is optimized for each size of table and breadboard offered.

We have performed extensive testing to optimize the thickness/size ratio of our breadboards. Larger sized breadboards over 5' (1.2 m) long are offered with a standard 110 mm thickness. Smaller sizes are available in both 2.4" (60 mm) and 4.3" (110 mm) thicknesses.

Compliance

The most widely used transfer function for the vibrational response of an optical table is compliance. In the case of a constant (static) force, compliance is defined as the ratio of the linear or angular displacement to the magnitude of the applied force. In the case of a dynamically varying force (vibration), compliance is defined as the ratio of the excited vibrational amplitude (angular or linear displacement) to the amplitude of the force causing the vibration. Any deflection of the tabletop is evident by the change in relative position of the components mounted on the table surface. Therefore, by definition, the lower the compliance value is, the closer the optical table is to meeting the primary goal of optical table design: minimized deflection. Compliance is frequency dependant and is measured in units of displacement per unit force (meters per Newton).

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Compliance Test Schematic

See the Vibration Isolation Tutorial for more information on compliance.

Compliance Measurement Procedure
An impulse hammer is used to apply a measured force to the top surface of the table or breadboard, and transducers attached to the surface detect the resultant vibrations (see diagram to the right). The signals from the transducers are interpreted by the analyzer and used to produce a frequency response spectrum (i.e., a compliance curve). During the development phase of an optical table, compliance curves are recorded at many points on the tabletop; however, the compliance is always greatest at the corners. The compliance curves and data published by Thorlabs are taken with the sensor located approximately 6" (150 mm) from the corner of the tabletop (closer to the edge for small breadboards), with the point of impact just inboard of the sensor. This test location represents the worst case data.

Unique Test Data Certificate
Each individual Nexus product is tested and shipped with a unique test data certificate and compliance curve. This provides more accurate data compared to the industry standard of using a single size-specific compliance curve to represent the entire product line. The compliance curves and data published by Thorlabs are from sensors located on the corner of the table and therefore represent the worst case data.

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Nexus Table Compliance Testing

Test Results

60 mm Thick Breadboards

Item #	Breadboard Size (W x L x H)	Compliance Curve (Click to View)a
B1212F / B1212T	12" x 12" x 60 mm
B1218F / B1218T	12" x 18" x 60 mm
B1224F / B1224T	12" x 24" x 60 mm
B1236F / B1236T	12" x 36" x 60 mm
B1818F / B1818T	18" x 18" x 60 mm
B1824F / B1824T	18" x 24" x 60 mm
B2424F / B2424T	24" x 24" x 60 mm
B2436F / B2436T / B2436FN	24" x 36" x 60 mm
B2448F / B2448T	24" x 48" x 60 mm
B3030F / B3030T	30" x 30" x 60 mm
B3036F / B3036T / B3036FN	30" x 36" x 60 mm
B3036Y	30" x 36" x 60 mm (No Holes)
B3048F / B3048T / B3048FN	30" x 48" x 60 mm
B3048Y	30" x 48" x 60 mm (No Holes)
B3636F / B3636T	36" x 36" x 60 mm
B3648F / B3648T / B3648FN	36" x 48" x 60 mm
B3648Y	36" x 48" x 60 mm (No Holes)
B3030A / B3030L	30 cm x 30 cm x 60 mm
B3045A / B3045L	30 cm x 45 cm x 60 mm
B3060A / B3060L	30 cm x 60 cm x 60 mm
B3090A / B3090L	30 cm x 90 cm x 60 mm
B4545A / B4545L	45 cm x 45 cm x 60 mm
B4560A / B4560L	45 cm x 60 cm x 60 mm
B6060A / B6060L	60 cm x 60 cm x 60 mm
B6090A / B6090L / B6090AN / B6090Z	60 cm x 90 cm x 60 mm
B60120A / B60120L	60 cm x 120 cm x 60 mm
B7575A / B7575L	75 cm x 75 cm x 60 mm
B7590A / B7590L / B7590AN / B7590Z	75 cm x 90 cm x 60 mm
B75120A / B75120L / B75120AN / B75120Z	75 cm x 120 cm x 60 mm
B9090A / B9090L	90 cm x 90 cm x 60 mm
B90120A / B90120L / B90120AN / B90120Z	90 cm x 120 cm x 60 mm

110 mm Thick Breadboards

Item #	Breadboard Size (W x L x H)	Compliance Curve (Click to View)a
B2436G / B2436U	24" x 36" x 110 mm
B2448G / B2436U	24" x 48" x 110 mm
B2460G / B2460U	24" x 60" x 110 mm
B3036G / B3036U	30" x 36" x 110 mm
B3048G / B3048U	30" x 48" x 110 mm
B3060G / B3060U	30" x 60" x 110 mm
B3636G / B3636U	36" x 36" x 110 mm
B3648G / B3648U	36" x 48" x 110 mm
B3660G / B3660U	36" x 60" x 110 mm
B3672G / B3672U	36" x 72" x 110 mm
B4860G / B4860U	48" x 60" x 110 mm
B4872G / B4872U	48" x 72" x 110 mm
B6090B / B6090N	600 mm x 900 mm x 110 mm
B60120B / B60120N	600 mm x 1200 mm x 110 mm
B60150B / B60150N	600 mm x 1500 mm x 110 mm
B7590B / B7590N	750 mm x 900 mm x 110 mm
B75120B / B75120N	750 mm x 1200 mm x 110 mm
B75150B / B75150N	750 mm x 1500 mm x 110 mm
B9090B / B9090N	900 mm x 900 mm x 110 mm
B90120B / B90120N	900 mm x 1200 mm x 110 mm
B90150B / B90150N	900 mm x 1500 mm x 110 mm
B90180BT / B90180N	900 mm x 1800 mm x 110 mm
B120150B / B120150N	1200 mm x 1500 mm x 110 mm
B120180B / B120180N	1200 mm x 1800 mm x 110 mm

• The compliance curves here are typical, and slight variations may occur between individual tables. Each table is individually tested before shipment and includes a certificate with the individual test data and compliance curve (see Unique Test Data Certificate section, above).

Note: Compliance data will be available soon for models with a greyed out plot icon. Compliance data is measured for each breadboard, and thus will be included with these models upon purchase.

Nexus^® Optical Tables and Breadboard Manufacturing

• Experienced In-House Design Engineers Create Models and Production Drawings
• Dedicated Tables Manufacturing Facilities for Repeatable and Consistent Production
• In-House Vibration Transmissibility and Compliance Testing 
• In-House Welding and Fabrication
• Custom Design Capabilities for Unique Optical Table and Breadboard Solutions
• Lean Manufacturing:
• Cross-Training Allows Staff to Meet Production Demands
• Use of Current Technology Leads to Increased Quality
• Efficient Organization Leads to Time Savings for Customers

Our team has over 25 years of experience designing optical tables, breadboards, and related accessories. We leverage this experience to ensure that our Nexus^® honeycomb optical tables and breadboards always meet two basic design goals: the natural resonances of the table should be as high as possible (well above the frequency of ambient environmental vibrations) and the table should be well damped (to quickly damp vibrations caused by equipment on the surface). To meet these goals, our engineers use a variety of tools to refine their designs, such as finite element analysis (FEA) and SolidWorks. FEA allows our engineers to evaluate various materials and to identify possible unwanted material stresses. SolidWorks is employed to build 3D models of every design.

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Nexus Table / Breadboard Cross Section, showing the (1) Top Skin, (2) Bottom Skin, (3) Side Panels, (4) Side Rails, and (5) Honeycomb Core

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Honeycomb Core of a Nexus Table During Manufacturing

Every Nexus optical table and breadboard is designed to be isotropic and symetrical in X, Y, and Z. For optimal thermal stability, only steel components are used in construction; no wood or plastic is used. Each table includes precision machined top and bottom mounting skins, an uninterrupted honeycomb core, and four side panels with finishing trim. See the animation to the right for a simplified illustration of how our tables are assembled. For more details on each step in the process, read below.

Precision Steel Construction for Thermal Stability

Thorlabs' Nexus tables and breadboards feature all-steel construction, including 5 mm thick top and bottom skins and a 0.26 mm thick precision formed and welded steel honeycomb core. The core is geometrically formed using accurate pressing tools, and geometric pitch is retained by using welded flat shims. The honeycomb core in our Nexus tables and breadboards extends from the top skin to the bottom skin without intermediate layers, leading to a stiffer, more thermally stable product.

The key aspect of the thermally stable Nexus design is symmetrical isotropic steel construction in all axes. Steel components expand and contract similarly, maintaining flatness during changes in temperature. The steel core extends from top to bottom skin without intermediate plastic or aluminum spill management structures that reduce the overall stiffness of the product and introduce a higher coefficient of thermal expansion. Steel side panels are used rather than wood, which can introduce environmental instability due to susceptibility to moisture.

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Heat-Shrink Packaging Being Applied Over a
Nexus Optical Table Prior to Shipment

Machined Finish with Minimized Contamination Packaging

Automated Finishing Process
Our Nexus tables and breadboards feature an automated orbital machined matte finish that is significantly smoother and flatter than our previous product line. The improved surface finish achieves ±0.1 mm (±0.004") flatness over any 600 mm x 600 mm area. Large radius corners are incorporated into the design, resulting in less pointed edges for lab safety.

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Diagram showing the location of the honeycomb core and side panels, which do not intersect with any screw holes.

Sealed Edges with Anti-Static Packaging
All optical tables ship with a heat-shrink film that protects the table from most contaminants, such as dust, from entering the product during shipment. For additional protection, we offer an optional finishing and packaging service that is suitable for customers that want to minimize the presence of airborne contaminants on the interior and exterior surfaces of the table or breadboard. This includes anti-static packaging, which has a metallic foil inner layer protected by a heat shrink film outer cover, and gap-free edge panel construction to reduce static charge and prevent dust from entering the product.

Mounting Hole Options and Pattern

Individually Tapped, Countersunk Mounting Holes
Prior to bonding the components of the table, each mounting hole in the top surface is tapped and slightly countersunk to ensure that components mounted to the table sit flat. The mounting holes are then cleaned and sealed on the bottom with vinyl film discs (non-sealed models) or sealing cups (sealed hole models, see Sealed Mounting Holes below). The vinyl film is easily punctured when using a hole for the first time. Cap screws can be finger tightened into the mounting holes of all Nexus tables and breadboards.

Reduced Hole Pattern Border
Our top surface hole patterns extend to the edge of the table or breadboard with only a 12.5 mm (0.5”) border, equal to half of a hole-to-hole spacing. This increases the usable area of the table and improves mounting option flexibility.

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Nylon Sealing Cups Installation During Manufacturing

Increased Screw Depth and Optional Sealed Holes
Our custom-designed core maker produces precision formed and welded honeycomb core strips. The core is shaped and installed so that it does not intersect with any screw holes (see photo to the right), allowing screws to be inserted far into the table, all the way to the bottom skin (for non-sealed-hole models). See the Specs tab for specific screw depth specifications, including outer border holes.

Sealed Mounting Holes
Tables and breadboards can be manufactured with nylon sealing cups glued to the underside of the top skin (see photo to the left) for liquid spill management. Sealed hole tables are available in all sizes and thicknesses, and the maximum screw depth is 1" (25.4 mm).

Mounting Holes on the Bottom Skin
Our breadboards feature at least four mounting holes in the base skin, permitting the secure attachment of standard or vibration isolating feet and allowing more flexibility for integrating breadboards onto tables or into setups in addition to using breadboard stands.

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Optical tables and breadboards are tapped using a high-speed
drilling machine.

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The surfaces of our tables and breadboards are sanded in our finishing machine.

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Tables and breadboards are bonded under pressure in our hot press.