About me


My name is Tim van Werkhoven, I’m currently working at ASML where I work on strategic analyses. Before this, I did my PhD research in the instrumentation group of Leiden Observatory under supervision of prof. dr. Christoph Keller and prof. dr. Hans Gerritsen.

During my PhD I worked on an STW project called Smart Microscopy, which is part of a larger Smart Optics Systems programme. Since this collaboration includes the Molecular Biophysics Group (MBF) in Utrecht, I work both in Leiden and Utrecht.

Besides the above, I’ve worked on analysis of transiting exoplanets with colleagues in Leiden, more specifically on the Kepler object KIC 1255b and an object obeserved by SuperWASP J1407. Both these systems are peculiar in their own way, the former appears to be disintegrating while the latter shows signs of a ring-system like Saturn’s.

Before my PhD, I worked on wide-field wavefront sensing for the European Solar Telescope at the Institute for Solar Physics in Stockholm for a year and did my master's in 2007–2008 on adaptive optics in Utrecht which I finished in August 2008.


 

Code

Since I started my master’s research in 2006, I’ve grown interest in adaptive optics systems and related topics such as wavefront sensing, coronagraphy, etc.. I am currently working in Christoph Keller’s research group at Leiden Observatory in the instrumentation group, with a collaboration with Hans Gerritsen’s Molecular Biophysics group. These are some of the things I have worked with or am still working on.

 

Smart Microscopy with NAOMi

My PhD research concerns Smart Microscopy, as part of the Smart Optics Systems STW programme. Smart, in this context, is not related to mental activity, but to active control of the optics. For my project, this will encompass implementing an adaptive optics system to a so-called two-photon excitation microscope

 

Transiting Expolanets

After I came to Leiden, I have been working on transitinig exoplanets observed with the Kepler satellite and the ground-based SuperWASP observatory. Analysis of one transiting exoplanet, KIC 1255b, revealed it to be disintegrating under the infuelnce of its host star. The light curve of J1407 observed with SuperWASP shows evidence for an extended ring structure.

 

Wide-field Shack-Hartmann wavefront sensing

During 2008 to 2009 I worked on site-characterisation for the European Solar Telescope (EST). The goal of this project is to understand where atmospheric distortions originate from through wide-field wavefront sensing. Better knowledge of how images are deformed by the atmosphere will allow us to build tailored correction systems to counter these deformations.

 

FOAM: Modular Adaptive Optics Framework

For my master’s thesis I designed and wrote a new framework for adaptive optics software, FOAM. The aim of this software is to provide a general framework for adaptive optics systems that can easily be implemented on a wide variety of platforms. The end product of this can be read in my master's thesis.

 

ExPo Adaptive Optics

Laurens Homs built an adaptive optics system for the Extreme Polarimeter (ExPo) during his master’s thesis together with other ExPo people. I contributed to this by implementing specific hardware in FOAM and get the setup running in the lab and at the William Herschel Telescope.


 

Code

Over the years I’ve written various pieces of code — for work or for fun — which are listed below. Hopefully somebody else can also use this, which is why you are free to copy, remix or adapt (not not sell) these in whatever way you see fit. You can also browse my github account or the gists I wrote to see if there is anything useful.


 

Type

When I have some spare time on my hands I sometimes make some doodles in XeTeX/LaTeX and Adobe Illustrator. Below are some doodles that resulted in something more or less finished.

 

Dutch railway map


An unfinished geometric railway map of the Netherlands with Futura.

 

Binas table 31

Binas is a high school reference textbook for the natural sciences. As an exercise I rendered table 31 (4th edition) in LaTeX.

 

XeTeX cheatsheet

A XeTeX document where I keep all the tricks and hacks I come across during writing. Includes stuff like \defaultfontfeatures, \textsuperscript, \@makechapterhead, \marginpar, \textbackslash, Ligatures, polyglossia, siunitsx, SmallCaps, UppercaseSmallCaps, SlashedZero, Swash contextuals, TitlingCaps, OldStyle numbers, \arraystretch etc. A snapshot rendering is included here, the newest version is available in the gist.


 

Publications

These are various things I’ve published somewhere in some way, categorised by medium.
 

Dissertation

On June 26th at 10:00, I successfully defended my doctoral dissertation titled“Lasers, lenses and light curves: adaptive optics microscopy and peculiar transiting exoplanets”. You can download a digital copy at the Leiden University repository. The XeLaTeX template I developed and used for this is available at github, feel free to use it!

 

Thesis

During 2007–2008 I did my master’s research on adaptive optics software. The result of this are FOAM, and the thesis itself. I wrote my thesis in the LaTeX markup language, and the source files are available for those interested. There is also a cleaned up version of the LaTeX files available which you can use as a starting point to typeset your own document.

You can download the following versions of my thesis:

Papers

You can find my publications in ADS or on Google Scholar.

 

Talks & posters

You can find some talks and posters in this directory, including the ones below.

Talks

  • AOIM9, South Africa, September 2013
  • NAC 68, Netherlands, May 2013
  • Focus on Microscopy, Netherlands, March 2013
  • FOM Biophysics, Netherlands, October 2012
  • AO Tomography session, Netherlands, July 2012
  • Adaptive Optics Microscopy, United States, February 2012
  • STW SOS programme meeting, Netherlands, February 2010
  • PhD introductory talk, Netherlands, November 2009

Posters

  • SPIE AS12, Netherlands, June 2012
  • NAC, Netherlands, May 2011
  • EAST-ATST workshop, Germany, October 2009

 

Teaching

Both during my undergraduate and my graduate studies I taught various courses at Utrecht University. Besides this I’m also a frequent helpdesk for colleagues which is why I’ve put together a small Python introduction as well as a LaTeX lecture.

 

LaTeX

Since LaTeX is an integral part of reporting results to the outside world, knowing how to typeset properly in LaTeX can be very useful indeed.

In my LaTeX lecture I briefly explain the parameter space of typesetting, and then go into some less-known detail of (La)TeX. This presentation assumes knowledge of LaTeX already.

Download:

 

Python

Besides teaching regular courses, I also wrote a two-part introduction to the Python programming language. The presentation consists of two parts, one introductory and one more advanced. These presentations are available under the Creative Commons BY-NC-SA license, which basically means you can do almost anything with it that you want.

All files are available on Dropbox or on GitHub.

 

Python 101

This presentation is an introduction to the Python language and treats the language syntax, treating objects, datatypes, flow control, functions and slicing along the way. The intended audience are people with little programming experience. If you are already familiar with a language this is probably not for you.

Python 102

Together with this presentation there are some exercises that aim to increase understanding of the language.

The second presentation goes more in the daily use of Python for numerical data anlysis with the packages numpy, scipy, matplotlib and pyfits. This is intended for people who already know some Python or programming in general, and are curious how Python can be used for data processing.

There are also some exercises for this presentation.