As one of radial horizontal drilling techniques, high pressure water jet drilling technology is capable of using mechanical or water jet apparatus to make a cavity at the selected coal seam.

This paper also introduces test results of spatial filter output and its action in laser focus system, by using a measuring apparatus for radial intensity distribution of laser beam.

This apparatus is enable to change the rotational speed of the pump in a wide range, to heat recirculating water and to load both axial and radial forces on the pump spindle.