in this research, thickness of two layers anti-reflection coating MRC) with refractive index na, of the end
facet of weakly-guiding semiconductor (compound ill-V), has been optimised to single Transverse Electro-
Magnetic (TEM) mode: in order that reflectance had less than 0, 0001. Reflection at the boundary is exactly
analogous to transmission-line models, with the result that continuity relation using dyadic admitance Y and
impedance Z operators at transverse plane, also by replacing the waveguide with homogeneous medium of
equivalent refractive index neg is equal to core refractive index nq 3 nm where wide of the wave guide can
be represented of active layer wideness w. Through the differential operator, backward electric field can be
form by matrix elements R, of reflection of interface, in such a way that reflectance at the plane z=0 is
obtained Double layers response frequencies at wavelength = 1, 55 tan operating, produced the thickness
/T/4 with n=1,46 (Si02) or 2,5870 (Si3N4 ZnSe). Difference of both refractive indexes (n,,,_;;=1'1,,,.1), minimum
reflectance is 0, 58 .1040 practically is zero) with optimum thickness Z/3 = 0,1938 um.
