New systems of coupling the FTIR spectrum signal amplification, mainly for self-assembling monolayers (SAMs) investigation, were developed. These systems based on hollow waveguide (HW) or half cylinder mirror, which have negligible attenuation in the mid infrared; enable to obtain high signal sensitivity of the samples absorption due to the very high signal to noise ratio. This has lead more detailed characterization of the SAMs molecular structure and its modifications. In addition, a linear dependence of the signal on the number of IR radiation rays incidents on length of HW, which has resulted in simple interpretation of results, was obtained.