Beam splitter with constant 1% reflectance at 40-to-50-degrees incidence angle at 1070 nm laser for camera-type laser profilers

For the purpose of spatter reduced welding of aluminum or copper, laser profile deformation is studying, ring or center-ring profile using a double cores fiber laser or by a Tamron-produced axicon lens through a single core fiber laser. An affordable and simple profiler is desired for measuring the laser deformation profile. Camera-type laser profilers are inexpensive and use a plate-type beam splitter (BS) as an attenuator. The plate-type BS is placed at a 45-degrees angle, and one plate attenuates the beam by less than 1/100. In the laser manufacturing field, laser profilers measure a focused laser. A focused laser with NA 0.1 is incident on a plate-type BS, where the angle of incidence of the laser is not only 45-degrees but also 40-to-50-degrees. We designed and developed a new plate-type beam splitter coating that reflects 1% constantly at 40-to-50-degrees angle of incidence at 1070 nm. We made a ring profile laser with a Tamron axicon lens by using a single core fiber laser and measured the ring profile with this new BS. This new BS enables accurate, inexpensive, and easy measurement of deformed laser profiles, such as ring or center-ring profile.