Rapid real time detection of cold atoms with minimal destruction

Abstract

A minimally destructive detector which was used for the interferometric measurements of the column density of cold atoms with a passively stabilized separated beam path interferometer was discussed. It was observed that the detection method was based on a fast photodetector and allowed for the real-time measurements with high temporal resolution. The interferometer used in the detection measurements was based on photodiodes and suitable for the measurement of fast dynamics in Bose-Einstein condensates (BEC) and real-time feedback using atom lasers. Results show that the photodiode based detection methods for BEC are compatible with modulation methods which employs squeezed light as the probe beam for sub-shot-noise-limited measurements.