Lasers for PIV Applications from Litron.
Litron offers an extensive range of flashlamp pumped and diode pumped PIV laser systems with output energies of up to 1 J per pulse and repetition rates of up to 200 Hz.
All of Litrons PIV laser systems are twin head devices, meaning that the PIV laser head contains two totally independent lasers.
The range of PIV systems is based around both the ultra-compact Nano series and the larger invar stabilised LPY series. The overriding factor that sets Litron’s products apart is quality. This is evidenced not only in the design and construction of the product, but also in its performance. In any imaging application the beam quality is of paramount importance as this completely determines the light sheet quality.
By choosing a suitable resonator configuration the output beam quality can be controlled to give a very smooth spatial profile which remains homogeneous as it propagates right into the far field. Such resonators are almost always of a stable or stable-telescopic configuration. Unstable Gaussian-coupled resonators are not in general ideal for visualisation applications. Such resonators yield output beams that contain very high spatial frequencies in the near field, and as they propagate a hole appears in the centre of the beam (a ‘donut’ beam profile).
This is typical of any such resonator and is a result of the physics of the system. It is therefore quite clear that if the beam is to be used in the near or intermediate fields(within 10 metres of the laser output) the light sheet formed is unlikely to be uniform, as the laser beam is not.
It is our philosophy to provide a laser system that suits an application. A ‘one system fits all’ approach, as offered by most manufacturers, does not allow the customer to optimise their process. For applications such as PIV Litron has developed resonators that will yield extremely uniform lightsheets whose pulse to pulse structure remains extremely constant. These are all based around our stable or stable- telescopic resonators.
Interesting 2016 paper about the use of Litron double pulse PIV lasers in Photoacoustic Doppler Velocimetry – A new method for blood flow measurement.