The BP100 beam profiler series instruments released by Thorlabs GmbH analyze the power distribution of laser beams with diameters ranging from 10 µm to 9 mm and with a dynamic range of 72 dB. The profilers, which cover the spectral range from 400 to 1800 nm, are available with Si and Ge sensors. They scan the beam by narrow slits in the X- and Y-directions and analyze it without the use of attenuators or lenses. Beam parameters, including diameter, ellipticity, location, centroid, 3-D profile and power, are calculated from the resulting power distributions. A Gaussian fit of the scanned profiles is displayed, along with the 2- and 3-D plots. A variable average function provides adjustable noise reduction and increases measurement accuracy. The instruments feature an RS232 and a graphical user interface and a driver set.