Laserquellen für präzise Schwingungsmessungen

Commercial HeNe lasers are relatively small devices with cavity lengths usually between 15 and 50 cm, but sometimes up to about 1 meter to achieve the highest powers, and optical output powers between 0.5 and 50 mW. The exact wavelength of red He-Ne lasers in vacuum is 632.991 nm and is refracted to about 632.816 nm in air.

The beam emitted by HeNe lasers is visible to the human eye and can be aligned without any aids. Its comparatively short wavelength makes it possible to focus the laser beam precisely on a very small measuring point, which makes the HeNe laser particularly suitable for measuring microstructures and fine details. 

Vibrometers with HeNe lasers are regularly used if a sufficient signal is scattered back from the measurement object, the measurement surface has sufficient reflectivity or measurements are to be taken through water, as light with a wavelength of 633 nm penetrates water almost unhindered.

Nowadays, besides some applications where the unique properties of HeNe lasers are required, SWIR lasers are the optimal choice for Laser Doppler vibrometry and Optomet takes the leading role in SWIR vibrometry. Due to a combination of higher output power and more sensitive photodetectors, SWIR vibrometers offer a higher SNR and are therefore particularly suitable for demanding measurement tasks where vibrometers with conventional laser sources reach their limits. 

Measuring even on dark, rough, curved or other surfaces with low reflectivity, infrared vibrometers eliminate the need to treat the surface. Vibration measurements over long distances are also the undisputed domain of SWIR LDVs, as well as measurements on glowing hot surfaces and on biological tissue. High temperature stability and a long service life offer additional advantages. All these characteristics also apply to the new SMART series from Optomet.