Technology

Overview
The FemtoSmart Galvo is a galvanometric scanner-based two-photon microscope which enables in vivo and in vitro functional imaging to be focused on the region of interest (ROI). The scanner consists of two galvanometer-based motor-driven mirrors, meaning that the focal spot can be positioned where required. The high accuracy and this positioning freedom support flexible approaches for ROI creation. In contrast to sampling all pixels in images, ROI scanning (e.g. along a predefined line) restricts scanning to the regions which are relevant for the scientist, resulting in faster recording, and elimination of background noise. This helps to reveal cellular signaling and action potentials.

Advanced 2D scanning methods
The advantages of the galvo scanner combined with the intelligent, user-friendly control software enables the user to use many scanning patterns covering the ROIs distributed across the field of view. These patterns have been developed based on the most frequent requests by neuroscientists. For example, multiple frame scanning focuses on cell bodies, multiple line scanning enables us to follow action potentials along dendrites, and random-access point scanning allows measurement or photo stimulation of subcellular components of the highest temporal resolution. Many features of the software, such as real-time display, analysis functions, ∆F/F calculations and integrated parallel data acquisition of electrical recordings promote greater understanding of the physiological processes under the focus of your research.

Multiple line scanning
Multiple line scanning has been developed for researchers who want to resolve dendritic and even spine activity of neurons approaching near real-time measurement mode. During this scanning mode, the X and Y mirrors direct the laser beam flexible along straight lines or complex curves. The scanner spends most of its time collecting signals from these lines, while the intermediate sections between the lines are skipped. In this way, the scanning speed and the signal-to-noise ratio (SNR) of the signals sampled from the multi-site ROIs increases 3- to 4-fold compared to frame scanning.

High signal-to-noise ratio
Scanning only the relevant part of the field-of-view, and skipping the background, result in a very high signal-to-noise ratio.
Photon collection efficiency is enhanced thanks to the shortest possible optical path realized by our patented travelling detector system
The most sensitive GaAsP photomultipliers (quantum efficiency less than 40%) collect scattered photons.

Folded frame scanning
This patented method enables imaging of a confined area along a line, where the shape of the selected regions can be straight or curved. This advanced scanning method is useful for imaging single cell bodies in different regions of the specimen, or following events along winding dendrites with their protrusions, even while the tissue is moving.

Photostimulus patterns
Uncaging, optogenetics, and other photo stimulation techniques are also supported by our unique scanning patterns and their combinations. Random-access point scanning can be used for stimulation in femtoliter volumes near dendritic spines where the duration of the stimulation, can be set from microseconds to seconds precisely to the experiment. The evoked signals can be followed along the dendrite by line scanning near simultaneously with the photo stimulation. The microsecond-scale switching time between the stimulation and imaging is achieved by using of a Pockels cell and gated detectors.

FemtoSmart Galvo. Focus on the details.