Uploaded July 2022 | Updated September 2026, 2 hours ago
From previous literature on the LISA mission, it is known that the interferometer arms are the most stable reference available. Using the LISA arms, multiple schemes of laser stabilization have been proposed and analyzed. The goal of this research is to re-examine and demonstrate an arm-locking laser stabilization technique that is compatible with the planned LISA hardware.
This research (J.T. Valliyakalayil et al., PRD 105:062005) introduces a novel method for enhancing the laser stabilization in the mission by locking the primary laser to two references concurrently – the on-board optical cavity and the arms of the interferometer. The locking scheme can be implemented using digital controllers with minimal or no hardware changes to the LISA baseline design. The preliminary results indicate that the technique can lower the residual laser frequency noise in the LISA science band by over 3 orders of magnitude: from 30 Hz/√ Hz to as low as 7 mHz/√ Hz, potentially allowing the requirements on Time-Delay-Interferometry (TDI) to be relaxed - possibly to the extent where first generation TDI is sufficient to realize the sensitivity of LISA.
The main challenge with this dual sensor (cavity + arm) approach is the undesirable slow laser frequency pulling which couples into the control system due to imperfect knowledge of the Doppler shift of the light in the LISA arms. To maintain the laser lock on the cavity, we have outlined the requirements on the Doppler shift knowledge, specifically on the Doppler constant, Doppler rate and Doppler acceleration terms. This research also proposes potential measurement schemes to realize these Doppler requirements using on-board measurements – the inter-spacecraft ranging information using Pseudo Random Noise (PRN) codes and, the interferometer response with pre-stabilized laser. Using these techniques, we can obtain the Doppler precision within a timescale of less than 2 hours.
Authors: Jobin Valliyakalayil, Andrew Sutton, Robert Spero, Daniel Shaddock, Kirk McKenzie
Presenters: Jobin Valliyakalayil, Andrew Sutton, Robert Spero, Daniel Shaddock, Kirk McKenzie
From previous literature on the LISA mission, it is known that the interferometer arms are the most stable reference available. Using the LISA arms, multiple schemes of laser stabilization have been proposed and analyzed. The goal of this research is to re-examine and demonstrate an arm-locking laser stabilization technique that is compatible with the planned LISA hardware.
This research (J.T. Valliyakalayil et al., PRD 105:062005) introduces a novel method for enhancing the laser stabilization in the mission by locking the primary laser to two references concurrently – the on-board optical cavity and the arms of the interferometer. The locking scheme can be implemented using digital controllers with minimal or no hardware changes to the LISA baseline design. The preliminary results indicate that the technique can lower the residual laser frequency noise in the LISA science band by over 3 orders of magnitude: from 30 Hz/√ Hz to as low as 7 mHz/√ Hz, potentially allowing the requirements on Time-Delay-Interferometry (TDI) to be relaxed - possibly to the extent where first generation TDI is sufficient to realize the sensitivity of LISA.
The main challenge with this dual sensor (cavity + arm) approach is the undesirable slow laser frequency pulling which couples into the control system due to imperfect knowledge of the Doppler shift of the light in the LISA arms. To maintain the laser lock on the cavity, we have outlined the requirements on the Doppler shift knowledge, specifically on the Doppler constant, Doppler rate and Doppler acceleration terms. This research also proposes potential measurement schemes to realize these Doppler requirements using on-board measurements – the inter-spacecraft ranging information using Pseudo Random Noise (PRN) codes and, the interferometer response with pre-stabilized laser. Using these techniques, we can obtain the Doppler precision within a timescale of less than 2 hours.
Authors: Jobin Valliyakalayil, Andrew Sutton, Robert Spero, Daniel Shaddock, Kirk McKenzie
Presenters: Jobin Valliyakalayil, Andrew Sutton, Robert Spero, Daniel Shaddock, Kirk McKenzie
