The unprecedented accuracy and stability of frequency references created by optical atomic clocks could form the backbone of next-generation quantum-limited optical-frequency positioning, navigation and timing networks. However, this requires correspondingly stable techniques for transmitting optical reference signals over atmospheric channels between locations of interest. Transmission of these optical signals comes with significant challenges, including: disruption by atmospheric turbulence; high Doppler shifts; and extreme power losses over long distances. Our research team has pioneered a technique that relies on the transmission of a continuous-wave optical carrier with active phase compensation to transfer the frequency reference in a stable manner.
PhD topics include:
- Weak light phase tracking through atmospheric turbulence: Free-space optical frequency transfer is always limited by the link-losses associated with atmospheric propagation. This project will look into the fundamental limits of frequency transfer at the quantum limit in the presence of significant scintillation.
- High-precision frequency transfer over highly dynamic atmospheric links: Doppler frequency shifts over atmospheric links, particularly within ground-to-space contexts, significantly exacerbate the difficulties associated with optical frequency transfer.
We are looking for a dedicated and enthusiastic student willing to learn from and collaborate with a team of optical researchers and physicists in the Astrophotonics Group (www.icrar.org/astrophotonics). The student will be given the opportunity to work in a world-class optical laboratory and to develop skills relevant to optical engineering, experimental physics and the budding Australian space industry. Additionally, this work will be conducted in collaboration with research groups from across Australia and around the world.