The LISA benchtop simulator at the University of Florida

Abstract

At the University of Florida, we are developing an experimental Laser Interferometer Space Antenna (LISA) simulator. The foundation for the simulator is a pair of cavity-stabilized lasers that provide realistic, LISA-like phase noise. The light travel time over the five million kilometres between spacecraft is recreated in the lab by use of an electronic phase delay technique. Initial tests will focus on phasemeter implementation, time delay interferometry (TDI) and arm-locking. In this paper we present the frequency stabilization results, results from an electronic arm-locking experiment, software phasemeter performance and results from a first optical experiment to test the TDI concept. In the future, the benchtop simulator will be extended to test several other aspects of LISA interferometry such as clock noise and Doppler shifts of the signals. The eventual long-term use of the LISA simulator will be to provide realistic data streams, including all the noise components, into which model gravitational wave signals can be injected. This will make the simulator a useful testbed for data analysis research groups.

Heterodyne laser frequency stabilization for long baseline optical interferometry in space-based gravitational wave detectors

“…for the given spacer and mirror specifications, which provides sufficient reference channel phase noise suppression according to (19) in either cavity. An issue that arises is the masking of reference channel phase noise induced frequency fluctuations in a differential measurement.…”

“…PM development at the University of Florida was initially focussed on supplying a processing unit for the University of Florida LISA Interferometry Simulator (UFLIS) [19] with a PM that meets the mission µcycle requirement. UFLIS was used successfully to demonstrate experimentally the use of TDI [20,21], armlocking [22,23], and GHz-sideband clock synchronization [24] on an optical test bench with real-time electronic phase delays of up to 32 seconds, which is the round-trip time in a 5 million km long interferometer arm.…”

A comprehensive simulation of weak-light phase-locking for space-borne gravitational wave antenna

“…(3), the free-running laser frequency noise is 0.17 Hz m Hz f  , which is several orders of magnitude greater than the requirement of LISA. Therefore, a series of approaches are proposed to suppress the frequency noise: pre-stabilization, arm-locking and a post-processing method called time-delay interferometry (TDI) [1,26]. By pound-drever-hall (PDH) pre-stabilization, the frequency stability can be achieved 4 30 Hz Hz 1 (2.8 mHz ) f   , which means the frequency noise can be suppressed to 4 4 5 10 m Hz 1 (2.8 mHz ) f     [27,28].…”

Breadboard model of the LISA phasemeter

“…This includes the generation of four analog signals for controlling up to two slave lasers and the implementation of control algorithms in the FPGAs. This can either be the digital equivalent to an analog frequency offset phase-lock (Diekmann et al (2009); Cruz et al (2006)), or the implementation of more complex algorithms, like arm-locking (Yu et al (2011)).…”