I want to split a collimated laser with a round shape with diameter of 3.5 mm (CPS532-C2 beam, collimated) in 3 collimated lasers in which the third beamlet will still have at least 3 percent of the original power of the laser. My laser has a wavelength of 532nm(+-0.3nm) and with a normal etalon there will be a lot of loss. An anti-reflection coated window on the entrance is needed so that the transmission is very high. The distance in between the lasers need to be 5 mm(later on we would like to tune this distance). The distance in between the lasers is dependent on the angle of the incident light with the etalon, but so is the transmission. Therefore we would like to have a large bandwidth for the transmission peaks.
So summarizing we want to get an etalon that can split a laser in 3, sometimes called a beam multiplier. The distance in between the lasers need to be around 5 mm.
We looked at using diffractive optics to split the beam but in our setup diffractive optics can not be used. The distance in between the beams on the surface should be independent on the distance in between the optics and surface.
Do you think it is possible to make such an etalon?