Building a two-photon microscope is easy

One time, years ago, I was asked (by a very nice person and an accomplished scientist) to write a book chapter. I didn’t want to. But I was working with a brilliant postdoc who might enjoy the project and we could do it together, and so I asked him. He said sure, so I agreed to do it. Then that postdoc moved on and the book chapter didn’t get written. It wasn’t even drafted. But the deadline was still approaching. I explained the situation, but my very kind colleague still encouraged me to write it. So the challenge was this: How can I get this job done as quickly as possible while still adding something of value?

I decided to write a very compact description of what it is to build a two-photon laser scanning microscope. It is basically a confocal microscope with no pinhole. The laser is really doing the heavy lifting. The optics can be optimized, but even mediocre optics can provide some decent performance. There’s no need to reinvent the wheel, and there’s no need to get too picky about it. The optics work we’ve done in the lab, and we continue to do both in the lab and the company, is quite finicky and detailed and time-consuming. But if you just need to get oriented and get the basics, there’s no reason to get lost in the weeds. Anyone can do this. This is 1980s era DIY. This is early punk. Let’s distill this craft to its essence. (But still, I don’t have all damn day, so I need to get this off my desk.)

The result was this (PDF link). I was just looking over it, prepared to be embarrassed, and I actually quite like parts of it. Maybe it merits mentioning it here. If you have someone new to two-photon imaging, it might not be a bad place to start. After this, there are a bunch of papers that get into the nitty gritty of building a system, a few of which can include this book chapter, this other book chapter, this article, and these two more recent articles.