Astronomy & Space Sciences
Title : | Design and development of miniaturized atomic frequency standard |
Area of research : | Astronomy & Space Sciences |
Focus area : | Optics, Atomic Physics, Micro Fabrication, Electronics |
Contact info : | jjohn@leos.gov.in |
Details
Executive Summary : | High accuracy frequency standards are the heart of many advanced space applications. Some typical examples include satellite navigation systems and precision clocks for high speed communication networks. In addition, many scientific missions also need high accuracy timing that is not possible to be achieved using conventional crystal oscillators. Present day atomic frequency standards for space applications are complex systems that comprise of gas filled cells and discharge lamps. These systems are bulky and power hungry and also seen leaking of the gas from the cells. They are based on ‘Optical Pumping’ technique that involve the use of a microwave cavity where the frequency of the microwave signal is locked to selected ground state hyperfine level via feedback through a resonant optical absorption. The atomic system is that of an alkali metal vaporform(Rb87 or CS133). These devices cannot be miniaturized beyond a limit due to the minimum size constraint of microwave cavity. In Coherent Population Trapping (CPT) based standards, there is no requirement of an external microwave field, the interrogation technique is all optical. With the availability of compact semiconductor laser that can be modulated, miniaturization of atomic frequency standards has become a practical reality. One of the key components of the frequency standards or clock is the vapor cell that holds the alkali vapor in a gaseous state. MEMS based technologies are now being used to develop miniaturized vapor cells. |
Co-PI: | Shri J. John, U R Rao Satellite Centre (URSC), Bengaluru |
Organizations involved