Software

NüPixel allows the use of mROI with Nüvü Camēras’ HNü 128, 512, and 1024 EMCCD cameras.
Easily set up multiple areas of interest to enhance the acquisition frame rate, and record data only for specific regions of the sensor.

The mROI feature allows the selection of specific areas of the detector performing acquisitions according to the activity across the field of view. The result is faster acquisitions as only the pixels of interest are read. Furthermore, users can position up to 9 fully customizable ROIs on the detector all at once. Better, this new feature maintains Nüvü Camēras’ unparallelled sub-electron noise and supports simple photon-counting imaging at faster frame rates for ultimate sensitivity.

Nüvü Camēras is the only EMCCD manufacturer that allows the combination of TDI acquisition with EM gain. To do so, simply select an EM TDI readout mode, add an external trigger, and start acquiring TDI images.
This unprecedented combination permits the coupling of Photon Counting with a TDI acquisition.

Also available in conventional readout mode.

Please refer to this article for more information on the TDI mode fundamentals, and on the reasons why it is interesting to make this readout mode available for EMCCD sensors. Nüvü's FAQ on TDI mode provides further information about the Time-Delay Integration mode itself.

The TDI mode is not a default and is an option that must be ordered with the camera.

Easily set up an FKM acquisition in NüPixel. FKM enables bursts of acquisitions with EMCCD cameras, with exposure times down to tens of microseconds.

There are two distinct areas in an EMCCD sensor: the imaging area and the storage area. In a regular (non-FKM) acquisition, once an image is acquired in the imaging area, it is shifted to the storage area before being readout. Then another image can be acquired in the imaging area. For EMCCDs, the whole process takes at best tens of milliseconds.

With FKM, a specific region of the imaging area is illuminated, the rest staying hidden from light thanks to a physical optical mask. An image is acquired in this region, and then the image is shifted just enough to be out of the illuminated area. Another image can therefore be quickly captured on the sensor, which is also shifted down outside of the illuminated zone. The process repeats itself for as many images as the user asked for the FKM burst. Once all the required images are exposed, all images are read at once. This enables the acquisition of short bursts of images with microsecond exposure times.

Of course, the maximum number of images in a sequence is limited by the position of the sub-area illuminated, the height of the sub-area, and the number of pixel lines on the sensor (counting the imaging plus the storage area).

The FKM is not a default and is an option that must be ordered with the camera.

Pixel binning is reading the detector’s pixel rows or columns in groups of two or more. Doing so leads to greater readout rates, as fewer pixels are scanned, as well as decreased readout noise, especially in low-light conditions, because summing photoelectrons in multiple pixels increases the signal. However, binning is a trade-off that offers a higher frame at the cost of decreased spatial resolution.

Horizontal binning happens in the detector’s serial register. The camera reads and combines several pixel values into one, and then sends this value to the computer. Due to the EMCCD architecture, horizontal binning does not increase the camera speed at high readout rates (10, 20, and 30 MHz) in EM mode as the serial register speed is limited by the controller’s horizontal pixel rate.

Vertical binning groups contiguous pixels in the same column during the readout process. The camera then reads the summed pixels as one. Contrary to horizontal binning, high pixel rate EM operations benefit from vertical pixel binning. As a rule of thumb, the camera speed increases linearly with the number of grouped pixels.

Enable binning X and/or binning Y in one click in NüPixel thanks to the "Binning" section.

Cropped-sensor mode acquisition is available to boost even further the frame rate performance of the camera.

The Cropped-sensor mode shares many similarities with the ROI: the user performs acquisitions with only a fraction of the detector area. However, whereas ROI only defines these regions electronically, such that the detector still collects photoelectrons from across the sensor’s entire area, the cropped-sensor mode must instead be used with a physical optical mask, which shields the unwanted region from photons.

In other words, the EMCCD must detect no light in the masked area, which translates into no photoelectrons (in contrast to ROI mode, where the sensor’s entire area may remain illuminated). Thus, unexposed pixels distributed on either side of the region defined by the optical mask will have detected no photons: their value is null. As such, the camera does not need to read an entire row but can instead ignore the unexposed pixels entirely.

This results in the virtualization of a smaller sensor, one limited to only the exposed region. Doing so further increases the acquisition speed compared to the ROI mode. Note that mROI is currently not supported in cropped sensor mode.