Fotodíodos - Parte 2

30 Setembro 2019, 14:00 • David de Castro Alves

Demonstração do efeito da resistência de carga na linearidade das medidas

EM description of matter

24 Setembro 2019, 09:00 • José Manuel Rebordão

Phenomenology of dispersion, Abbe Number.

Relation P(E). How this relation is used with Maxwell equations; linear, non-dispersive, homogeneous and isotropic media. Causality principle. Formal relations for linear and uniform media and for anisotropic media. Linear and nonlinear optical regimes, the relevance of the electrical field of the H atom to gauge the linearity or non-linearity of the models.

Radiation from a dipole in the near and far regimes (https://youtu.be/QK5KrYakSIU, https://youtu.be/NB2AP7jvqvA). Brief reference to near-field optics.

Dielectrics, Lorentz model and explanation of dispersion. Formal impact of the complex nature of the susceptibility. Real and imaginary parts of the permittivity, wave number and refraction index. Modelling of attenuation / absorption, Beer-Lambert law. Effect of multiple resonances, normal and anomalous dispersion. Sellmeier equations.

Metals, Effective permittivity. How general equations for dielectrics can be used also for metals if permittivity is replaced by the effective permittivity; asymptotic behaviour of metals for very high frequency. Plasma frequency. Drude model. Characteristics of the propagation constant, index of refraction and attenuation as a function of frequency. Plasmonic and forbidden bands. Explanation of the visual appearance of metals (Cu, Au, Ag). Use of metals as reflectors for frequencies smaller than plasma frequency.

Data base RefractiveIndex.Info for the optical properties of materials.

NEXT CLASS

Fresnel equations. Polarization. Optics of non-isotropic materials.

BIBLIOGRAPHY

Saleh, Fundamentals of Photonics, Ch. 5.

http://refractiveindex.info

Fotodiodos - parte 1

23 Setembro 2019, 15:00 • David de Castro Alves

Introduction to PHOTONICS

17 Setembro 2019, 09:00 • José Manuel Rebordão

Overview and scope of Photonics

Photonics as an industry and several of its markets, worldwide.

Content of the course and Assessment: Monography - 35%, LabBook - 45% - Short presentations - 20%.

NOTE
Schedule: One student request to change the schedule to wednesdays, 13:30-15:30h. This is be assessed, relying on an Erasmus student and room availability.