The UF-LISA Phasemeter

LISA Image

The UF-LISA data aquisition and processing capabilities have been developed using radio-frequency (MHz) embedded electronics obtained from Pentek, Inc. The system's field programmable gate arrays (FPGAs) are programmed with digital filters to perform the essential functions of the LISA interferometry data tracking and aquisition system. Real-time data processing can be used to simulate the LISA inter-SC laser link or generate control signals for LISA tracking systems. Meanwhile, measured LISA-like laser beatnote observables can be stored for "on the ground" data-processing and gravitational wave extraction.

The UF-LISA phasemeter tracks and measure the phase of the pre-stabilized laser beatnote observables using a digital offset phase-lock loop (PLL). The PLL's feedback information represents the phase of the laser beatnote and can be accurately recorded with a 0.1 ucycle/rt(Hz) precision at Fourier frequencies of 0.1 mHz to 100 kHz. The precision of the phasemeter readout is critical to the capabilities of the LISA interferometry measurement system.

Further applications of the real-time digital simulator, including advanced arm-locking controllers and delay-lock-loops for pseudo-random noise code tracking, are also being developed and tested.

For more information refer to...

Publications:
James Ira Thorpe et al, "Electronic phase delay; a first step towards a bench-top model of LISA"
  2005 Class. Quantum Grav. 22 S227 doi:10.1088/0264-9381/22/10/014
James Ira Thorpe et al "Experimental verification of arm-locking for LISA using electronic phase delay"
  2005 Physics Letters A, Vol. 342, Issue 3, pp. 199, ISSN 0375-9601, doi:10.1016/j.physleta.2005.05.053
Rachel J Cruz et al, "The LISA benchtop simulator at the University of Florida"
  2006 Class. Quantum Grav. 23 S751 doi:10.1088/0264-9381/23/19/S14

Dissertations:
James Ira Thorpe LABORATORY STUDIES OF ARM-LOCKING USING THE LASER INTERFEROMETRY SPACE ANTENNA SIMULATOR AT THE UNIVERSITY OF FLORIDA
Shawn Mitryk LASER NOISE MITIGATION THROUGH TIME DELAY INTERFEROMETRY FOR SPACE-BASED GRAVITATIONAL WAVE INTERFEROMETERS USING THE UF LASER INTERFEROMETRY SIMULATOR