Forward and backward waves

[abaset]

Hi all;
In a reflection and transmission problem of light off a dielectric slab or Fabry-Perot resonator, is it necessary to describe the wave in the slab as a sum of forward and backward wave or just a forward wave propagate in the relevant direction is enough. ?
knowing that in the above medium, the wave in the medium of incidence is Ei +Er with Er = rEi and the field medium of transmittance is Et = tEi

In this case, is there any difference between oblique and normal incidence.

any insight is very much appreciated

 

[Valerie Park]

.Yes, it is necessary to describe the wave in the slab as a sum of forward and backward waves. This is because, for oblique incidence, the forward and backward waves may have different amplitudes and phase shifts which must be taken into account for accurate analysis. For normal incidence, the forward and backward waves have the same amplitude and phase shift, so a single forward wave description is sufficient.

 

[charng]

.

Hello,

In the study of light propagation in a dielectric medium, it is important to consider both forward and backward waves. This is because when light interacts with a dielectric slab or Fabry-Perot resonator, it can undergo both reflection and transmission. The reflected wave (Er) and transmitted wave (Et) are both components of the total incident wave (Ei). Therefore, it is necessary to describe the wave in the slab as a sum of both forward and backward waves.

In terms of normal and oblique incidence, there may be some differences in the way the waves propagate and interact with the medium. For example, at normal incidence, the reflected and transmitted waves will have the same polarization state as the incident wave. However, at oblique incidence, the polarization state may change due to the different refractive indices of the medium. Additionally, the amplitude and phase of the reflected and transmitted waves may also vary with angle of incidence.

I hope this helps to clarify the importance of considering both forward and backward waves in the study of light propagation in dielectric media. Thank you for your question.