Arm Locking is a clever method of pre-stabilizing the Nd-YAG lasers used for LISA interferometry measurements which exploits the long-term, low-frequency stability of the LISA arm-length as a reference against which the laser frequency is stabilized. This stabilization method requires no additional hardware and may be performed completely using digital software filters to track the laser frequency and control the laser frequency actuator. Thus, this locking scheme may be performed independently or in conjuction with the well-understood ULE-cavity Pound, Drever, Hall stabilization.

The UF-LISA interferometry simulator is in an excellent position to experimentally test these stabilization methods with a hardware-in-the-loop simulation using UF's laser benchtop, digital feedback controlers, and phasemeter readouts. The electronic phase delay (EPD) unit replicates the inter-SC laser-light travel delay, frequency Doppler shifts, and noise coupling characteristics of the LISA mission and provide the ability to generate arm-locking control signals in on the ground. The many publications associated with these tests and their results are outlined below.