Instrumentation Laboratory Project Page
Project: CCD Cold Atom Imaging
Primary Investigator: Dr. Samir Bali
Purpose: In our lab we study the dynamics of
atoms that have been cooled using laser beams to microKelvin
temperatures, and arranged into a regular periodic array known as an
optical lattice.The most direct method for imaging cold atom dynamics
is imaging via a fast (short exposure time) sensitive CCD camera. The
camera is used to either track changes in either the center of mass of
the cold atom cloud or in the width, as a time sequence of millisecond
exposures is recorded.
IL helped us build a cold atom imaging system with low dark current levels for imaging few million atoms. Importantly, IL created a LabVIEW interface that enables the sequence of precise timing events necessary for measuring cold atom dynamics. The imaging system they built for us offers significant improvements over previously reported systems in terms of timing jitter, pixel density, and resolution while offering comparable well-depth, quantum efficiency, read noise, and dark current. Our system cost is less than $5k, much less than the $45-50k price tag on comparable commercial systems. For all these reasons, our fast imaging system is of significant interest to the cold atom community.
IL Comment: Researcher required a system that
would allow for the creation of custom digital waveforms (on the
microsecond level) for triggering various experimental apparatus
(accepting TTL level signals) in their lab. Another function of the
system is to interface with a CCD camera to capture images of the cold
atom “clouds” as they are being formed\destroyed.
Given the precise timing requirements, we decided to a use a master\slave setup in LabVIEW through the use of a Windows system and Real-Time Operating System (RTOS). The RTOS is required to send out the digital TTL signals with microsecond precision. However, that is only one half of the system. For the exposures the researcher required from their camera, they selected a camera that is primarily used for astronomy applications, which have long exposure times. Since there were no pre-existing LabVIEW drivers available for this camera, the I\L had to create these from scratch in order to get camera exposures in the millisecond range. In the end, this system performs as requested for the researcher and has many of the features that commercialized systems provide while being at least 1/10 of the cost.
Cost to researcher: $716.32