Gaussian-beam tracing in 3D

Type of contract
Traineeship contract for a period of 4 months within the EGO Optics laboratory, funded by the EGO Consortium.

Description
The Virgo interferometer is the most sensitive gravitational-wave detector in Europe. It was realized in partnership between the French and Italian institutes CNRS and INFN. It involves a wide collaboration of almost 200 scientists and engineers. After a deep modification of the interferometer, to give birth to a new generation detector called Advanced Virgo (AdV) that will use improved mirrors, higher laser power and signal recycling techniques in order to increase the sensitivity by one order of magnitude, the instrument is now being commissioned to become fully operative with the aim to join the LIGO detectors in the near future. The EGO consortium (European Gravitational Observatory), located in Cascina, near Pisa-Italy, hosts the Virgo detector and has been also deeply involved in the design and construction of Advanced Virgo. In particular, the EGO optics group is in charge of the input optics (INJ) and scattered light control (SLC) system for AdV. The responsibilities of the Optics Group have now increased with the commissioning phase, including the coordination of the whole laser and injection system, the sensing and control of the interferometer and a major role in the optical characterization of the interferometer. Due to the complexity of the AdV interferometer, the optical setup has to be accurately simulated and the laser beams have to be clearly traced in a drawing in order to ease the commissioning phase. Up to now, this task was accomplished by means of a 2D Gaussian-beam tracing software known as Optocad. This software, open-source and written in Fortran, has some limitations due to the fact that it only propagates the beam on a fixed plane in 2D. Actually, due to the presence of vertically oriented wedges in core optics of the AdV interferometer, 2D is no longer enough to get a clear picture of the beam path and a 3D tracing is now required. Within this frame, the EGO Optics Group would like to develop a new software tool to trace the AdV beam in 3D. Despite the existence of commercial tools such as Optics Studio and similar, no tool is currently able to propagate a Gaussian beam with assigned only the positions and shapes for the optical components but no indication on the order the beam will meet each of the components. During this internship, we propose to review existent open-source codes starting from Optocad, extend its capabilities to 3D Gaussian-beam tracing, possibly working in Python, and depict the results of the ray-tracing with a suitable package such as Blender or similar. Accurate check of the software predictions against well-assessed tools and/or experimental outcomes are a part of the proposed work. Participation to the possible publication of the results will be part of the internship work.

Requirements
Applicants should be in their last years of study in optics or physics. The work will be at a level of Bachelor thesis (equivalent to thesis for “laurea triennale” in Italian). English required. Good knowledge of at least one among Fortran, C, Python/Matlab required. Good attitude to programming and simulation work, along with knowledge of Gaussian optics is mandatory. Familiarity with work on optical benches will be an asset.

Place of work
EGO - European Gravitational Observatory - via E. Amaldi 56021 Loc. S.Stefano a Macerata - Cascina (Pisa) ITALY.
Considering the lack of public means of transport to reach the site, it is preferable having a car.

How to apply?
Interested candidates are invited to fill in the Traineeship Application form and send it, together with the CV, to jobs@ego-gw.it

Further information
For the whole duration of the traineeship, EGO will pay a gross monthly wage of 500,00 euro and offer the lunch service at its canteen during working days to the student. Interested candidates can have a look at all of the conditions of the contract here: Traineeship Agreement. : Traineeship Agreement

Closing date for applications
Until position is filled

Contact
Antonino Chiummo, Ph
Email: antonino.chiummo@ego-gw.it
Phone: + 39 050 75 2543, +39 050 752601



Scanning Fabry-Perot Imager

Type of contract
Traineeship contract for a period of 4-6 months within the EGO Optics laboratory, funded by the EGO Consortium.

Description
The Virgo interferometer is the most sensitive gravitational-wave detector in Europe. It was realized in partnership between the French and Italian institutes CNRS and INFN. It involves a wide collaboration of almost 200 scientists and engineers. After a deep modification of the interferometer, to give birth to a new generation detector called Advanced Virgo (AdV) that will use improved mirrors, higher laser power and signal recycling techniques in order to increase the sensitivity by one order of magnitude, the instrument is now being commissioned to become fully operative with the aim to join the LIGO detectors in the near future. The EGO consortium (European Gravitational Observatory), located in Cascina, near Pisa –Italy, hosts the Virgo detector and has been also deeply involved in the design and construction of Advanced Virgo. In particular, the EGO optics group is in charge of the input optics (INJ) and scattered light control (SLC) system for AdV. The responsibilities of the Optics Group have now increased with the commissioning phase, including the coordination of the whole laser and injection system, the sensing and control of the interferometer and a major role in the optical characterization of the interferometer. The laser beam is phase modulated in order to lock the interferometer cavities and control several degrees of freedom to achieve the sensitivity goals of the project. Not only the amplitude of the sidebands has to be monitored, but also their transversal field distribution carries information about the optical defects in the interferometer. In order to monitor both the parameters, we use two different devices: a Scanning Fabry-Perot cavity for the amplitudes, and a Phase Camera to monitor the transversal field distribution. Within this frame, the EGO Optics Group would like to develop an innovative spectrum analyzing cavity which could be mounted on AdV optical benches for characterizing the phase modulated fields, both in amplitude and in field distribution, by using a particular configuration known as “self-imaging cavity”. This will make this device unique since no equivalent scanning cavity can be found on the market. During this internship, we propose to review the design of this cavity, also by using optical simulations. A complete device will be assembled/characterized to verify its compliance with AdV requirements. This will include the measurement and optimization of cavity alignment and of the control electronics. Participation to the possible publication of the results will be part of the internship work.

Requirements
Applicants should be in their last years of study in optics or physics. The work will be at a level of Master thesis (equivalent to thesis for “laurea specialistica” in Italian). English required. Good attitude to experimental work is mandatory, familiarity with control systems and related hardware/software will be an asset.

Place of work
EGO - European Gravitational Observatory - via E. Amaldi 56021 Loc. S.Stefano a Macerata - Cascina (Pisa) ITALY.
Considering the lack of public means of transport to reach the site, it is preferable having a car.

How to apply?
Interested candidates are invited to fill in the Traineeship Application form and send it, together with the CV, to jobs@ego-gw.it

Further information
For the whole duration of the traineeship, EGO will pay a gross monthly wage of 500,00 euro and offer the lunch service at its canteen during working days to the student. Interested candidates can have a look at all of the conditions of the contract here: Traineeship Agreement. : Traineeship Agreement

Closing date for applications
Until position is filled

Contact
Antonino Chiummo, Ph
Email: antonino.chiummo@ego-gw.it
Phone: + 39 050 75 2543, +39 050 752601








[Last update: 6 December 2016]