Optical Tables Tutorial
The Need for Optical Tables
In research and application laboratories, it is often necessary to conduct experiments or take measurements in a vibration-free environment. However, sources of vibration such as air conditioners, heat pumps, and road and rail transportation systems contribute to a largely unavoidable vibrational background noise that is coupled to the surrounding environment. Optical systems comprised from multiple components that must be individually mounted and aligned in a precise and rigid fashion are particularly vulnerable to vibration-induced performance degradation.
Many types of experiments are severely hampered, or even made impossible, by small vibrations. For example, many laser applications require a beam waist of a few microns; if the position of this spot is critical to system performance (e.g., using an ion laser to pump a jet stream dye laser), then vibrations with amplitudes in the micron range will inevitably cause experimental failure. Since visible light has sub-micron wavelengths, interferometry-based experiments (including holography) may also be impossible to perform in the presence of vibrations, even if they are sub-micron in amplitude. Optical and/or mechanical machining or probing of semiconductor wafers requires similar stability. Finally, if an experiment utilizes mechanical elements that move or vibrate, it is often necessary to vibrationally isolate these components from all other critically aligned optical elements.
