08-Optical Tables.pdf - Qioptiq Q-Shop

Microbench Nanobench Tube System C Positioners Rail Systems Mounts and Posts Mirror Mounts
Strong Internal Damping
Table tops exhibit strong internal
damping that both minimizes their
response to external shocks and vibrations
and dissipates the energies of any
activated vibrational modes of their top
plates. The internal dam-ping characteristics
of Table Tops are particularly critical
in cases where they are supported on
vibration-isolation systems.
Many manufacturers use viscoelastic
adhesives to attach top and bottom
plates to honeycomb cores, a practice
that substantially reduces the stiffnesses
of final Table Top structures. All epoxy
resins used by TMC are hard-setting and
supplemented by dam ping masses. This
approach eliminates both aging effect
and outgassing. The damping characteristics
of our Table Tops are individually
tuned to their structural resonan ces.
TMC‘s firm adherence to these design
prin ci ples in manufacturing its Optical
Table Tops results in superior-quality
Table Tops exhibiting stiffness that has
yet to be equalled. Their low compliances,
the recipro cals of their dynamic
rigidities, are readily evident from their
corner-compliance curves.
TMC offers three levels of damping:
Maximum damping:
For holography, interferometry, spectroskopy,
also recommended in particularly
noisy vibration and for puldes lasers.
Dry Damping
The damping of the Optical Table Tops is
based on a system of broadband dry
damping, which damps all existing
resonances. Dry damping is preferable to
oil-based dampers. Oil‘s characteristics
can change over time and hidden oil
reservoirs are always in danger of being
pierced by an end-user customizing his
system.
An Optical Top‘s resonant frequency will
vary based on load, distribution of load,
temperature, and even the presence of
the dampers themselves. Therefore, in
practice, it is difficult to tune the
dampers to the top‘s resonance. The
broadband damping technique is
therefore the most effective way to
damp an Optical Top.
Standard damping:
For less sensitive applications. This
broadband damping level provides a top
with performance characteristics that
exceed the majority of other manufacturers‘
highest performance levels.
Nominal damping:
For general lab work when the main
consideration is a rigid, flat mounting
surface.
Frequency (Hz) Frequency (Hz) Frequency (Hz)
We present below the corner-compliance curves for the three damping levels. In this example a table with the dimensions 1200x2400x300 mm is used. To convert from in/lb
to mm/N multiply by a factor of 5.7. Example: 10 -6 in/lb x 5.7 = 5.7 x 10 -6 mm/N.
276 Phone numbers: US +1 585 223 2370 UK +44 2380 744 500 Singapore +65 6499 7766