Macs and French keyboards

Look at this - a blog post in the morning!  Shouldn't I be at work?

Today the Ecole Polytechnique is hosting a talk about the master's and PhD programs that they offer, so I'm all the way out at Paliseau waiting in Linda's and Drew's office.  It's about an hour commute, and the campus is vast, so I knew I wouldn't be able to locate the talk on my own and tagged along with them this morning.

While I wait, I can fill in the details of my work yesterday.  Iryna needed the optics room in the morning for some last-minute data collection, so I chugged through the spectra I took yesterday, searching for lasing thresholds.  It was an Igor adventure.  I plotted each spectrum in turn and zoomed in on a particular peak to check its amplitude.  While I was looking at the reference cavity, a true Fabry-Perot, I could fit the peaks to nice Gaussians, but the spectrum goes all weird and jaggedy as the tilt angle increases, so fitting to an analytic function was out of the question.  Instead I just recorded the maximum intensity of the test peak as the pump energy decreased.  It occurs to me now to check whether there's a significant diference between the Gaussian-fitting method and the maximum-amplitude method, using the true FP.  I doubt that there is, but it would be good to make sure.

Anyway, I generated three plots of amplitude vs pump energy, and it looks like the threshold increases with the tilt angle, though I still want more data.  I always want more data - perhaps this isn't necessarily a good thing.  I've certainly noticed while taking the data that the energy needed to begin seeing a spectrum at all, even if it's a fluorescence and not a lasing spectrum, increases with tilt.

I did get the chance to take threshold data for a new cavity right before I left work yesterday, so I can add that to my plot.  This afternoon I hope I can finish up with my little threshold investigation for the time being, and tomorrow maybe move on to the pump position questions.

In the evening, I met my friend Eric, who has been traveling around Europe for the past month as a celebration of free time before beginning grad school in the fall.  He's in Paris this week.  We wandered Le Marais for a while and found a pretty good restaurant, where I was entirely boring and ordered a chicken sandwich.  It was a tasty chicken sandwich, at least.  Then more walking and talking.  We ended up by the Pantheon, having heard some very good street musicians and eaten delicious Berthillon ice cream along the way. Quite a pleasant evening.

Today is Wednesday, so several of us are planning on visiting the Louvre. Stay tuned to (hopefully) hear about some more incredible works of art!