5 páginas, 3 figuras, 2 tablas.-- Trabajo presentado al 1st International Congress on Instrumentation and Applied Sciences celebrado en Cancún (México) del 26 al 29 de Octubre de 2010.The theoretical concepts are necessary to obtain the optical constants of several materials in
InGaAs Photodiode and are possible to obtain from experimental dates of reflectance and
transmittance and several optical coverings can be designed. In this work we will show how to
calculate the reflectance of photodiode for all the wavelengths (each 50 nm, according to the data
of refractive index), as well as changing to the angle of incidence and polarization s and p, besides
the calculation of the transmittance of a multi-layer ones of InGaAs. A multi-layer is constituted by a
series of piled up laminae some on others and in this work we will suppose that they are
homogenous, isotropic and plane-parallel, the structure is in the first case we have a transparent
layer of NSi, late second layer of InP (Zn), soon a third layer of InGaAs and finally a later of InP (S).
These multilayers are destined for optical applications, in our case will be case of study in the case
of the photodiodes, the thicknesses of the layers will be of the order of the wavelength of incident
radiation, which in the case of radiation IR/NIR is translated in thicknesses of approximately
between 1y 100 nm. For the determination of optical constants they are possible to be done of
different ways in our case we will concentrate in 1) Measured of reflectance in normal incidence.
These measures only provide the value of n in the case of means transparents.2) Measured of
reflectance in two angles of incidence. It allows to the use of natural light or polarized.3) Two
measures of R p R s in two angles of incidence outside the normal one. 4) Rs and Rp in a single
angle of incidence outside the normal one.Peer reviewe
