Electric field enhancement computation for integrated detector of THz range

One of most promising detectors for THz range is the hot electron bolometer on basis of semiconductor compound HgCdTe [1] .Experimental sensitivity is greater than theoretical prediction for such device. The most credible hypothesis is that metallic contacts to the detector play the role of antenna, which is greatly increasing an electric field in the active element. The main probable evidence of this is a strong frequency dependence of the system response similar with those for simple dipole antenna. The Method of Momentum (MOM) [2] was used for the numerical computation of the self-consistent electric field distribution in the system. Sometimes this method is called BEM as well (Boundary Element Method). It is one of a number of widely spread methods of computational electrodynamics. This method was used because all other methods have significant restriction for the evaluation flat but very thin conductor structures. MOM greatly works for such kind of structures. Main advance of MOM is necessity of the discretization only of the structure surface, not the volume. It is grounded on the integral formulation of electrodynamics. The solution is written in the form of linear combination of basis functions. Linear system is solved than. In the case of existing the dielectric region the Surface Equivalence Principle (SEP) were used. For complicated dielectric systems FEM (Finite Element Method) is better, but it requires great computation power. A computed electric field enhancement is very high, it achieves a few hundreds. Detectors sensibility depends on electric field energy in active element, so it is proportional to square of electric field. Maximum antenna energy enhancement is approximately -70000. The frequency dependence for bowtie and dipole antenna is similar. For bowtie antenna exist two maximums and electric field enhancement is stronger.