In the kHz lab we generate THz pulses with the center frequency of 1.5 THz and a bandwidth of about 3 THz, via optical rectification of the Ti:sapphire pulses. In order to filter the pump field, in a first step, its intensity is reduced by diffuse scattering at a PTFE filter which is transparent for the THz field. In a second step, the residual pump field is filtered by absorption in a Si wafer. Both, PTFE filter and Si wafer, are installed at the Brewster angle for the THz radiation.