Winning pictures of last year (2020)

Dissertation: Entwicklung von Drahtgitterpolarisatoren für Anwendungen im ultravioletten bis in den vakuumultravioletten Spektralbereich

Beschreibung

The topic of my work was the investigation of nano-optical elements, which allow the control of the polarization of light (wire grid polarizer) for short wavelength (in the vacuum ultra violet). For that, I investigated a variety of materials and the influence of fabrication techniques. The content of the work and several personal key experiences presented on this hat in a much interwoven manor.

Stemming from a liking of mine for historical European marital arts, reenactment and forging the main themes are a castle, swords and a knight.  On the path of this knight, those experiences are represented. The knight is walking along its way by turning a crank.

This first action of every morning is brewing a cup of coffee. For that a fully function mill (the wind mill in the background) is used to grind the beans and to infuse the coffee (a little banner says “instant human just add coffee”) while the camp fire is used the boil the water (referring to an epic hiking tour after a SPIE event in California). The first waypoint is reached when I investigated iridium gratings as structures for VUV wire grid polarizers (the grating is reassembled by the portcullis, the inscription above the gate saying “Ir” consist of a piece of silicon on which the letters are etched into an iridium layer). As these grating elements are not able to fulfill the task, the portcullis cannot open enough for the knight to pass through. Hence, the errant knight hast to continue his journey. In the next passage (the green paper mechanisms open when the black parts are pulled) the wedding with my wonderful wife is represented. At this time, I proclaimed: “My thesis will be done before the birth of my first child!” Just to prove me utterly wrong, my second child was born before (shown as well by the mechanism).  

The next steps of my journey lend me to the PTB in Braunschweig. While working at the PTB I was puzzled by the amount bureaucracy. This is perfectly depicted by the 3D puzzle. During this time I passed along several other gates (resembling different materials) which do not open fully.  Another very important step in my life was the restoration of a historic timber frame house. This is depicted by a laser cut plywood model (the model is actually true-to-scale!), which I had to erect with hot glue during the hat presentation (it is a running gag that I recommend the use of hot glue). The final gate (the inscription says “LER”) shows the end of my PhD work were I took very fine deviations of the grating structure ( i.e. line edge roughness) into account.

Apparently I am whistling while walking down the hallways of the institute. By turning another crank the towers of the castle rise while the theme song of game of thrones is playing (all mechanically!).  

Carefully observed the knight is walking along a circle with several steps in it. One may believe that there is another hidden philosophic truth behind…

Since I always build the electronics for other hats mine has absolutely no electronics on it (this has always been a running gag) but still many features are actually functional. This is achieved by 18 individual 3D printed involute gears. These gears are nested into each other in order to drive two independent mechanism on a common center axis (much like a Swiss watch).  Further, the gearing includes a total of 14 ball and needle bearings of different types carefully designed such that the whole system is not statically indeterminate. Every day I see the hat I am just amazed by this. Constructions like this gearing are the reason why it is called the art of engineering! Unfortunately, a single image and short description cannot do justice to the sheer number and attention to detail of this features.

I am very grateful for this gorgeous hat made by a bunch of even awesome people!