Sumários

Ressonant cavities and gaussian waves - a review

6 Março 2023, 10:00 • José Manuel Rebordão

Review of topics of direct relevance for LIGO:
Fabry-Perot interferometer. Different ways to model the phase difference as a function of the controlled parameters. Example: laser ressonant cavity with or without etalons.
Gaussian waves: description of the modulus and phase terms. Gouy phase. Higher order Hermite and Laguerre modes.
Gaussian waves as eigenmodes of a ressonant cavity.
Imaging gaussian waves using lenses.

BIBLIOGRAPHY
Saleh, Fundamentals of Photonics - section 2.5 (FP interferometer) & sections 3.1 -3.4 for gaussian waves and higher modes
NEXT CLASS
LIGO subsystems. Mode cleaning

Holography and wave optics (aula dada por Alexandre Cabral)

3 Março 2023, 12:00 • José Manuel Rebordão

[Aula dada por Alexandre Cabral. J. Rebordão encontrava-se num júri de agregação]

Light as a wave and the interference phenomena.

The principle of holography and the “how to make” an hologram.

The Denisyuk hologram as a single beam reflection Hologram.

Spatial Filtering, difraction and polarization optics

1 Março 2023, 11:00 • Alexandre Pereira Cabral

Alignment of a spatial filter in order to generate high spatial coherence waves.
Observation of interference and diffraction phenomena. 
Manipulation of light polarization with polarizers and waveplates.

LIGO

27 Fevereiro 2023, 10:00 • José Manuel Rebordão

Gravitational wave (GW) detectors: history, general architecture. Links with General relativity: GW was polarization, frequency and strain.

General subsystems and function of GW detectors.

Review of Fabry-Perot (FP) cavities: interference between may waves with losses; Finesse. Examples.

NEXT CLASS

FP physics. Phase.

Back to LIGO subsystems.

2D sampling

24 Fevereiro 2023, 12:00 • José Manuel Rebordão

2D Sampling. Main equations of Shannon theory. Artifacts in case of non-band-limited function or disrespect of Nyquist frequency.

Superposition of periodic patters. Analysis in direct and Fourier space.

Visual band: reference to the MTF and to the Contrast Sensitivity Function.

Emergence  of low frequencies from linear combinations of pattern-related frequencies.

Stables and unstable superpositions.

Applications: Hidden indicia, printing, security.

 

NEXT CLASS

Introduction to LIGO architecture.