Tag: two-photon

Guidance for designing an objective from scratch

Several people have reached out for guidance on designing and building an objective from scratch, when they have little-to-no background in custom optics. Here are some notes on the topic, in broad strokes, focused on the practicalities.



A 20 mm working distance objective for two-photon imaging

The working distance is marked as 22 mm in this image, which is measured on-axis, from the center of the last lens. Practically, the mechanical working distance will be 20 mm.

We have designed a 20 mm working distance…



Open, easy laser-scanning microscope software: LSMAQ

Years ago, Benjamin Judkewitz wanted to try some new techniques out with laser scanning two-photon microscopy. However, the software we were using was rather cumbersome to modify. So he wrote his own software from scratch…



Collection optics: How big is big enough?

 

To advance deep imaging in multiphoton microscopy, it is essential to attempt to collect each photon generated in the scattering…



Headplate designs

Multiphoton imaging with micron resolution in living animals can be challenging because they…



Mirrors and lenses for multiphoton microscopes

There’s been an interesting discussion on the Confocal listserv, and we’ll quote some of that discussion below. We’ve always used protected gold and silver mirrors for our multiphoton systems. That’s still what we recommend…



A resonant-galvo-galvo module from Vidrio/ScanImage

This could be handy for some of you. Resonant scanners are fast, but inflexible. You can’t tell them where to go. They just oscillate at a fixed frequency. All you can do is control the amplitude….



Laser power modulation: EOMs and AOMs

Fast laser power modulation in 2p systems is typically done with a Pockels cell. Conoptics sells one that is optimized for common Ti:Sapph systems, and that’s what many people end up using.

Pockels cells are a…



Real-time tracking and 2p imaging with sub-ms timing

In this work, the authors used fast optical motion tracking and 2p imaging to measure the activity of individual neurons in freely moving animals. No surgery. No optical window. No restraint. And all the benefits of…



PMT power supply

I was cleaning house a bit, and among my old files I found this, which might be worth sharing. Years ago I made a centralized power supply for a custom 2-photon imaging system I built. There were two…



Analysis algorithms: performance quantification and ground truth

We recently tweeted about a preprint from Eftychios A Pnevmatikakis and Andrea Giovannucci (code). The preprint is on motion correction for calcium imaging data. It is a nice quick read and discusses earlier work in the…



Tons of 2p spectra – twophotondyes.com

 

Daniel Fiole is curating a nice resource for 2p cross sections: twophotondyes.com

There’s a lot here. It’s not just dyes, he has links for fluorescent proteins as well, and there’s 3p…



Ripple noise on PMTs in 2-photon imaging – Part 2

The recent post on ripple noise generated some comments and additional discussion. Go check out the comments on that post. For example, Peter Rupprecht shared some snapshots an oscilloscope display showing the signal from the…



Ripple noise on PMTs in 2-photon imaging

Andrew Lim wrote in to discuss strategies on dealing with ripple noise in 2-photon imaging systems, particularly when using resonant scanners. He writes:

This isn’t so much a tip as a problem with resonant two-photon scopes that…



Postdoc position with Duguid in Edinburgh

A world-class in vivo patch clamp electrophysiologist, Ian Duguid, is recruiting to his lab. Ian provides excellent training, and his lab is in a tremendous setting: Edinburgh. Ian’s also one of the…