Autobiography Stefan Hell

By the time I had completed my doctoral thesis in the summet of 1990,1 was
convinced that thcre must be a way to improve resolution in a more fundamen-
tal way. With the two-lens approach I had at least found a beginning, albeit only
within the limits imposcd by diffraction. But the mindset that I had constructed
for myself picking textbooks apart told me that physical phenomena must exist
that should bc suitable to overcome the barrier radically. So much progress had
been made in physics in the 20th Century that there had to be at least a single phe-
nomenon that should enable lens-based optical microscopy with resolution at the
nanometer scale.
My stipend had run out, and I had asked Professor Hunklinger if I could stay
on another year to work on the resolution problem. But optics wasn,t his field.
It was clear that I would have to go my own way, which wasn’t easy, because at
that time there were no structures in Germany to give young researchers a start.
Usually, you needed a mentor for whom you had worked for several years while
working towards your habilitation, a postdoctoral degree required for having one,s
own students and to lecture. A mentor was out of the question, nor was applying
for a postdoctoral position in the USA an Option. First, I didn’t know anyone there;
second, my English was rather modest.
Fortunately my grandparents, who had meanwhile also emigrated, had saved
10,000 Deutschmarks, which they gave me as present when I was awarded my
doctorate. I sat for a couple of weeks thinking about how I could build a ‘double
confocal microscope’ with two juxtaposed lenses and used the money to pay an at-
torney to file a patent on it. Since I had worked in the milieu of a start-up Company,
I thought that I may be able to persuade Leica or perhaps another big Company to
support the development. But things worked out differently: Roelof Wijnaendts
van Resandt introduced me to his formet PhD Student Ernst Stelzer, who had
succeeded him as head of the microscopy group at EMBL. I indicated to Ernst
that I wanted to work on the resolution question, and he offered me a stipend for
a few months, on condition that I would apply for external stipends for the rest of
my stay. One has to appreciate that at the time there was a surplus of physicists in
Germany and the prospects of doing academic research were poor. However, I had
just learned the hard way that if s. a. mistake to seek economic security and that it’s
much better to do what you enjoy.
I therefore wrote up a small application for a stipend to the German Research
Foundation (DFG), the main fundingbody in Germany. Essentially, I described the
double-lens microscope and my view on the prospects of improving the resolution
in a lens-based light microscope. Although located in Heidelberg, the EMBL is le-
gally outside Germany, which meant that I couldn’t be funded by the DFG unless
my application was formally supported by a German university. Since I could no
longer appeal to Professor Hunklinger, I consulted the directory of physics pro-

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