Lasers are widely used in scientific research,
medicine and industry. In many application lasers are
desired to have high beam quality. Therefore it is quite a
crucial that, scientist and engineer need to work together
to ensure the laser output having reliable performance.
The poor beam quality or unmonitored beam may cause
unsatisfactory production as well as undesired treatment.
There are many ways and a variety of instruments
have been developed to measure the propagation factor
M2. There are four main methods of beam–measurement;
camera-based system, knife-edge method, slit scanning
method, and variable pinhole method. Each has specific
advantages and disadvantages. Camera based profiler for
example, is instantly record and display the entire optical
pattern that impinges on the camera surface. But it has
limitation cannot measure width greater than ~ 60 m
and is limited spectral range . Furthermore, it is very
sensitive to brightness and high potential of damage if
expose with high power laser. Base on these weaknesses,
other alternative method need to be considered.