The coupling between beam tilt and longitudinal path length readout in a setup representing a LISA test mass interferometer was reduced to below 2 µm/rad using a two lens imaging system. This was achieved by the use of a homodyne equal arm-length Mach-Zehnder interferometer and suppression of the dominating effects of higher order Gaussian modes and longitudinal actuator movement. The latter wa...

Linewidth measurements of a distributed feedback (DFB) fibre laser are made using delayed self heterodyne interferometry (DHSI) with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are w(L) (MZI) = (1.6 ± 0.2) kHz and w(L) (MI) = (1.4 ± ...

This paper deals with the analysis of the pressure wave signals generated in an aluminium-stepped sample. The ultrasonic signals are generated using pulsed Nd-YAG laser and detected using a He-Ne Heterodyne interferometer. The pressure wave signals at constant laser power are recorded at various directions with respect to source laser direction and the intensity of various frequency components ...

We report on interferometric range transceiver technology demonstration. The goal of this work is to reduce risk for a follow-on gravity mission to the Gravity Recovery and Climate Experiment (GRACE) by demonstrating performance of a heterodyne interferometric laser ranging instrument appropriate for a follow-on gravity mission to GRACE at the NASA Technology Readiness Level (TRL) 6. In order t...

A single chord two-color CO2/HeNe (10.6/0.633 μm) heterodyne laser interferometer has been designed to measure the line integral electron density along the mid-plane of the MAST Upgrade tokamak, with a typical error of 1 × 10(18) m(-3) (∼2° phase error) at 4 MHz temporal resolution. To ensure this diagnostic system can be restored from any failures without stopping MAST Upgrade operations, it h...