Microsemi Chip Scale Atomic Clock (CSAC) technical status, applications, and future plans

Microsemi's CSAC was developed from 2001 to 2011 and represented revolutionary technology for atomic clocks. The use of Coherent Population Trapping, pioneered at NIST, enabled a significant reduction in size, weight, and power compared to conventional gas cell clocks. Last year, Microsemi released an updated version of CSAC that improved the operating temperature range and reliability. Development of the technology continues at Microsemi to meet the current and future applications. This paper provides some historical background, design description, a detailed technical status of CSAC including performance data from production testing. Also, the paper will contain a description of both the original and future applications. Finally, a description of the future development plans with the goals of increased performance, further reliability improvements, and wider environmental tolerances. The improvements include wider temperature range from −40°C to 80 °C, improved drift and temperature stability, radiation tolerance and RoHS 6/6 compliance.