The easy way to measure the important things about your laser
- by Ilan Haber
It is getting increasingly clear to people that if you are using a laser for some process, in order to keep that process consistent, the laser output also has to be consistent.
Until now, most people know you have to measure and control the laser power. People are used to having a laser power meter with or built into their system. However, the beam position and size can also have a critical effect on the laser performance. If the beam is not in position or has changed size, this can have a drastic effect on the work being performed by the laser.
Why do industrial users of lasers rarely measure beam position and profile? I think the reason is that it is expensive, complicated and difficult to implement. Beam profiling is a very sophisticated tool that gives you a whole lot of information about your beam. Figure 1 is a typical beam profile with dozens of pieces of information. It is very useful if you need it but is also very daunting if all you want is some basic control information such as has your beam moved or has it changed size.
Now at last, there is a device that looks like an ordinary power meter, is the same size, in the same price range but measures spatial beam characteristics also. That is the new BeamTrack series of laser power/position/size meters.
The BeamTrack sensor can now allow you the greater control you need to keep track of your laser beam. With a simple screen on your Vega or Nova II power meter that is easy to understand (See figure 2), you can keep tabs on your complete laser performance including spatial position and size. It is sensitive enough to tell you if anything significant has changed in your beam. You can measure the beam position to better than 0.1mm resolution and the beam size to similar resolution. And remember – it does all the other things an ordinary power/energy meter does.
For a demonstration of the BeamTrack in operation see: http://bit.ly/YPDdWK
-By Ephraim Greenfield, CTO, Ophir Photonics Group
You might also like to read: The new Ophir BeamTrack sensor- You won’t believe how useful it is!
also you can track your beam profile with the NSOM measurements.the resolution of such meeasurements is very high especially if you’re using the NSOM tips with a nanometric holes like 50,100,150nm.