Bethel University's Atomic, Molecular and Optical lab used a Quarto in their experiment to lock a laser to a two photon transition of Rb-85 with the Quarto acting as both a Lock-In amplifier and tunable servo. The lab wrote up a very nice application note about the setup. Some highlights about the Quarto:
Overall, our lab has had a very positive experience using the qNimble Quarto. The Arduino code was easy to learn, and the ability to send serial commands to the Quarto provided a seamless interface with the experiment. The technical support offered by qNimble was invaluable, including answering emails with questions and tips and pointing us to helpful online forums. We are very grateful for their assistance and are benefitting from adding the Quarto to our laboratory apparatus.
The qNimble Quarto is a flexible data acquisition and experiment control device. Low latency & jitter, high-resolution A2Ds & D2As, a high sampling rate, and a facile user interface make the Quarto a high-performance tool for any laboratory.
You can read the full application note here.