Development and testing of a Spatial Light Modulator as a phase screen generator for the high-order adaptive optics testbench GHOST

Background on the topic:

The Phasing and diagnostic station is the tool/instrument that will optically phase and align the primary mirror of ESO’s ELT.


Its calibration unit provides diffraction limited and seeing limited sources from visible to IR wavelengths. It provides a point source used in most cases. It includes also a turbulence generator using a spatial light modulator (SLM), used for specific tests and system verifications.

We are looking for an enthusiastic master's student for a 5-month internship to work with the turbulence generator of the calibration unit.

The aim of the project/successful candidate is to:

  • Produce a user interface to the SLM using MATLAB or Python (Python is preferred). A similar interface has been developed a high-order adaptive optics testbench in operation (GHOST) and will be used as a starting point and adapted as needed.
  • Characterize the SLM used in our system. This includes a verification and update of its look-up table (linearizing the response of the SLM).
  • Using the OOPAO simulation package (Python-based AO simulation tool), create suitable scripts which generate and save atmospheric model, and adaptive optics residuals. Similar tools exist for the GHOST and will be used as a starting point and adapted to the needs of MAICAL.
  • Build a simple optical setup to evaluate the optical performance of the SLM. The setup should allow the quality of the PSF to be assessed and compared to expected PSFs for the given turbulence/phase screens applied to the SLM.
  • Document your progress such that the tools developed are usable by others.


The successful candidate should have the following traits:

  • Background in physics or engineering and comfortable analysing complex systems.
  • Proficient with Python, (MATLAB also an option).
  • Experience with laboratory experimentation and optical setup (a plus if you can design optical systems too)
  • Good teamwork and communication.

Supervisor:  B. Engler