The course week
The preliminary course programme: each day is a combination of theory and practice in successions. As a carrier, you will design an optical delay line.
Monday: The Big Picture and Systems Engineering
These type of instruments are always co-existing with other equipment.So before you can start designing you need to know the essence of what you are doing.What is critical and where and what are the margins.How to approach such a project and how to gain insight the background of requirements.
Contributions from: Prof.R. Munnig Schmidt from the Delft University of Technology
The case starts with an introduction to the optical design and their use in optical aperture synthesis applications. (Interferometry for imaging, nulling applications).Next, in teams, several delay line designs will be compared so a choice of the best design can be made with respect to the optical requirements. After this you need to find an effective optical design that can be used to measure the optical path differences.Workshop, using Zemax to analyse the optics in the delay line with a focus on tolerancing. Further you will work with wave front analysis and pupil imaging while moving the delay line. Also the accuracy of the alignment is part of the assignment.
Contributions from: S.Baumer from Philips; E.van Brug from TNO
Based on the functional requirements of the optical delay line, the challenges for control are discussed. These include actuation for a high dynamic range, servo behaviour, vibration rejection, sensor noise, closed-loop stability and others. An introduction of suitable control design methods is presented to achieve nano-meter positioning accuracy.
Hosted by P. Nuij from the University of Technology Eindhoven, N. Doelman from TNO
Thursday: Opto-Mechanical Design
Mechanics plays a dominant role in the design of a delay line. Apart from putting things together high quality mechanics will guarantee best performance in terms of optical quality/stability and control performance. Lightweight and stiff structures are therefore crucial in achieving this goal. The design of the existing ESO delay line will be used to explain the requirements for such a structure. Emphasis will be put on the interactions with the other key technologies needed (optics, control and electronics) and on the mechanical design itself.
During the second part of the day the participants will be challenged to participate by designing a specific part of the cat’s eye (optical section of the delay line) using their own experience and the information provided earlier during the day. This will be done in teams of approximately five.
Contributions from: J.Nijenhuis from TNO and Prof.R.Munnig Schmidt from the Delft University of Technology
Friday: Actuation, Sensing and Dynamics
For the last day some still missing elements will be presented that are necessary to realize high performance active positioning and control systems for optics. First of all an overview is given on electromagnetic and piezoelectric actuators, optical position measurement systems and capacitive sensors. Further also attention will be given to the performance determining mechanical system dynamics and vibration isolation. The new fi eld of adaptive optics will also shortly be touched upon.
Contributions from: Prof.R. Munnig Schmidt from the Delft University of Technology, A. Rankers from The High Tech Institute