Rigorous diffraction of Hermite-Gaussian beams by a double slit: TM polarization case

A rigorous numerical analysis of the diffraction of finite-size Hermite-Gaussian beams by two slits is presented. The case of TM (Transversal Magnetic) polarization and oblique incidence is considered. We assume the double slit is ruled onto a metallic screen of non-zero thickness h, width ℓ and separation d. Far-field spectra and transmission coefficients are analyzed as a function of several opto-geometrical parameters, i.e. the wavelength λ, slit width ℓ and separation d. Particular emphasis is put on the description of the energy diffracted along the incident direction Ei because of its applications on optical-metrology. Finally, the validity of a well known scalar property Ei=2τ/λis studied within the vectorial regime.