Hi, Cornelia Hofmann (@coenneli) at the helm for this week 😃
No, I didn’t start on the #VendeeGlobe2020, I am a theoretical physicist in strong-field attosecond science, aka shooting atoms apart with very short laser pulses.
But I don’t have cool lab shots, so here we are 😉
Let me introduce myself and my background a bit, before we dive into all that jargon up there.
In February of this year, I started a new postdoc fellowship from @snsf_ch at @uclmaps. Before coming to London, I got my BSc, MSc and PhD all at @ETH_physics in Zurich,
and then had a postdoc position at @maxplanckpress Institute for the Physics of Complex Systems in Dresden. And yes, most of the time my “complex system” consisted of a helium atom and a laser field. #womeninSTEM
Besides doing research, I enjoy teaching on various levels, be that participating at outreach events demonstrating mind-boggling laser experiments, taking high-schoolers to an astronomy observatory, or teach and supervise students at the university level.
As hinted above, sailing is a dear hobby of mine, even if I can’t do it as often as I'd like. Additionally, music takes up a lot of my free time. I played in orchestras, conducted ensembles, sang in choirs, love to play the piano, and listen to a variety of artists and genres.
So, what am I going to talk about during my takeover? Here’s my current plan (I might adapt it, depending on your feedback and responses):
Later today I will give you an introduction to my field of research, scale you down from the world of nano down to atoms and electrons. ⚛️
On Tuesday and Wednesday, I intend to talk about some of my research projects, grouped by theme. Hopefully, this will lead seamlessly over to a discussion of the bigger picture, possible applications, and long term goals of this kind of research on Thursday.
Friday will be dedicated to more of my personal views and experiences so far on my academic path, and on the weekend we can hopefully come to a lighthearted conclusion.
I hope you will find some interesting tidbits over the course of the week. Most importantly, feel free to ask about anything, so I can freestyle and/or adapt my future threads 😁
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1. LASER = Light Amplification by Stimulated Emission of Radiation (a) 2. Electron 3. Excited state atom 4. A Photon (I don't think there is a lasing material capable of producing gamma range photons) 5. Diffuse 6. Population Inversion
7. 3 Levels (with just 2 levels, as one approaches population equality, stimulated emission and absorption would start balancing each other out, preventing population inversion and thus there is no amplification of the light) 8. b) The energy gap between excited and ground state
Happy Sunday everyone!
It has been an adventurous week (in many ways 😁).
I recently came across this fun little #laser quiz and thought that would be a nice conclusion to my week here. So take a guess and play along 🤗
1. What does LASER stand for?
a) Light Amplification by Stimulated Emission of Radiation
b) Light Absorption by Simulated Emission of Radiation
c) Latent Absorption of Specified Elliptical Radons
d) Latent Amplification of Stimulated and Elliptical Radons
2. What particle plays the major role in the process of lasing?
Hi everyone :-D
We have reached the weekend already. Over the last few days, I hope I managed to give you a small glimpse into my research field. But one promise I have not yet delivered on: Where will all of this lead? What's the point?
First of all, I don't think I have to convince you that the quantum tunnelling phenomenon is found in all kinds of fields. Recently I came across a paper discussing tunnelling times during a photosynthesis cycle in an organic molecule. doi.org/10.1007/s13538…
Many might be familiar with Scanning Tunnelling Microscope (STM) technique to investigate surface structures with (sub-)atomic spatial resolution (or make an atomic stop-motion movie 😄)
I have this itch to swing back to talking about physics after yesterdays more meta thread, much like a pendulum always striving towards the middle position, but constantly overshooting. BTW, pendulums are an excellent representation of how short laser pulses are created!
You have probably heard (or learned) that laser light has a very defined colour (one specific wavelength/frequency), and all photons are in phase with each other, all their waves are perfectly synchronised (coherent).
(Image source: miridiatech.com/news/2014/02/l…)
It is evening again, and I finally find a moment to check in here. How are you doing?
I feel like my apartment has turned into a bit of a "sauna for beginners": higher room temperature than I would usually keep in wintertime, and more humid than usual in general (despite having open windows)...
I'm going to switch my plan around a bit. The exciting opportunities for future scientific and technological developments derived from #attoscience (and if I find the time, a project using nano-objects to modify the spatial dependence of my laser fields) will come later.
Good evening! While my fan heater is doing its job, why don't we catch some electrons?
In yesterday's thread, the electrons which have been freed from their bound state by the laser mostly just oscillated around (steered by the electric field) and eventually flew off and away (until they hit a detector).
However, not all electrons are so lucky. For some of them, their trajectory ends up looking almost like that lasso up there. This is if their kinetic energy at the end of the laser pulse is not quite enough to escape from the Coulomb potential of the atom/ion.