•
•
•
4.3
where T = 1/ν is the period, measured in seconds. The wave number k z has the unit of an
inverse length. It is related to the wavelength λ via
We note that ν and ω are independent of n, while k and λ change when the wave travels to
media with different n.
Electromagnetic waves have some extraordinary properties that are derived in detail
in Appendix A.3:
The electric and magnetic field vectors are perpendicular to each other and also
perpendicular to the propagation vector,
The electric and magnetic fields are perpendicular to the propagation direction,
hence electromagnetic waves are transverse waves.
The electric and magnetic vectors have a constant, material-dependent ratio. If
the electric field is along the x-direction and the magnetic field is along the ydirection, this ratio is given by
where
is the impedance of free space.
Optics of flat interfaces
In this section we repeat the major relations that describe an electromagnetic wave
traversing an interface between a medium 1 and medium 2, as illustrated in Figure 4.1. We
assume the two media to be non-absorptive. Therefore, only the real parts of the refractive
indices are present. We denote them by n 1 and n 2 .
A part of the incident light is reflected, where the angle of the scattered light θ r is
equal to the incident angle θ i ,
The other part enters medium 2, where the angle of the refracted light θ t is related to θ i via
•
•
4.3
where T = 1/ν is the period, measured in seconds. The wave number k z has the unit of an
inverse length. It is related to the wavelength λ via
We note that ν and ω are independent of n, while k and λ change when the wave travels to
media with different n.
Electromagnetic waves have some extraordinary properties that are derived in detail
in Appendix A.3:
The electric and magnetic field vectors are perpendicular to each other and also
perpendicular to the propagation vector,
The electric and magnetic fields are perpendicular to the propagation direction,
hence electromagnetic waves are transverse waves.
The electric and magnetic vectors have a constant, material-dependent ratio. If
the electric field is along the x-direction and the magnetic field is along the ydirection, this ratio is given by
where
is the impedance of free space.
Optics of flat interfaces
In this section we repeat the major relations that describe an electromagnetic wave
traversing an interface between a medium 1 and medium 2, as illustrated in Figure 4.1. We
assume the two media to be non-absorptive. Therefore, only the real parts of the refractive
indices are present. We denote them by n 1 and n 2 .
A part of the incident light is reflected, where the angle of the scattered light θ r is
equal to the incident angle θ i ,
The other part enters medium 2, where the angle of the refracted light θ t is related to θ i via