Sumários
Dual resonant MI
18 Maio 2026, 14:00 • José Manuel Rebordão
Operational point of cavities, enabling maximum
phase sensitivity.
Common and differential signals, dark fringe
configuration
Intracavity and reflected fields from a FP cavity.
Resonance and anti-resonance conditions. Cavity gain.
Analysis of a single non-resonant MI: the
reflectance of a non-resonant MI from the SYM port. Optical Gain enhancement.
Science signal coupling to the cavities. GW signal
emerging from cavities.
Analysis of the different components of the cavity
transfer function. Poles.
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GW signal at the ASY port. Power recycling.
nalysis of the F-P cavity with the scattering matrix
15 Maio 2026, 09:00 • José Manuel Rebordão
Layered
media – matrix methods, Transfer M and Scattering S matrices. Lossless and
reciprocal systems. Examples.
Analysis
of MI and Fabry-Perot cavities with matrix methods. Reflectivity,
transmissivity and surtention coefficients. Resonances, anti-resonances.
Finesse. Pole of a cavity. Behaviour of phase around resonances.
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CLASS
Analysis
of the dual resonant MI
Michelson interferometry (class 1 of 3)
13 Maio 2026, 17:00 • Bachar Wehbe
Setup
of a Michelson Interferometer (MI), using amplitude splitting, and analysis of
the generated interferograms in several configurations.
Usage of cube beam splitters and polarisation optics to control laser beam
polarization.
Assessment
of how the MI can be used to measure relative displacements of one of the
mirrors, using a piezo electric stage actuator to move one of the mirrors.
Analysis
of several polarization optical elements (polarizers, polarizing beam splitters
and wave plates) using a polarimeter (an instruments that measure the
polarisation state of light).
Acquisition of interferograms using a CMOS 2D camera for post processing.
Wavefront metrology (class 1 of 3)
13 Maio 2026, 15:00 • Alexandre Pereira Cabral
A Shack-Hartmann wavefront sensor was built based on an array of lenses that divide / sample the incoming wavefront into small sub-apertures, focusing independently the light from each lens in a 2D sensor that captures the focal plane pattern. This pattern was processed to obtain the position of each focus point from each individual lens.
An incident plane wave was created using a spatial filter and a collimated lens to produce a grid of equidistant focal points, the reference position, while several distorted waves (corresponding to a point source from an optical fibre in controlled positions) result in an uneven distribution of points that were referenced to the ideal plan wave situation in order to determine with the sensor the position of the fibre tip, using the Shack-Hartman sensor to measure an unknown wavefront based of the focus shifts from the calibration.Main architectural elements and subsystems
11 Maio 2026, 14:00 • José Manuel Rebordão
Optical
architecture. Detection architecture. Beams architecture. Examples form several
GWO’s.
Some
thermal and optical properties of Silicon (target material for Voyager LIGO).
Main
subsystems: Housing (HAM and BSC’s). Pre-stabilized laser system and its components.
Input Optics functions and elements. Core Optical Components overview.
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CLASS
Layered
media. Fabry-Perot cavity. PDH method.