Figure 1

The microwave Inerferometer as a precision phase detector. The system consists of the microwave ($\mu \mathrm{W}$) pump source, the interferometer, and the phase sensitive readout of the DP. The BP is used to drive the mixer LO input, and a variable attenuator ($\alpha$) and phase shifter ($\varphi$) are used to balance the interferometer.Reuse & Permissions

Figure 2

Phase noise spectra of the interferometric measurement systems. The noise spectrum of the conventional interferometer (see Fig. 1) was measured at Fourier frequencies $f<1\mathrm{Hz}$. The solid line gives the fit to the noise of stationary experiment. Rotation adds bright lines at the harmonics of the rotation frequency plus some excess broad band noise above 0.1 Hz (highlighted by the dashed box). The noise spectrum of a power recycled interferometer is displayed at $f>1\mathrm{Hz}$. No rotation was applied. The interferometer was based on low-loss waveguide components to enhance the efficiency of power recycling and boost its phase sensitivity (see description below). The accompanying solid line is the phase noise model of $1.7\times {10}^{-8}/f+2\times {10}^{-11}\mathrm{rad}/\sqrt{\mathrm{Hz}}$.Reuse & Permissions

Figure 3

Amplitude and standard error for the September 2007 data set as a function of offset frequency from the rotation frequency ${\omega }_R/2\pi$ in units of ${\omega }_{\oplus }/2\pi$.Reuse & Permissions

Figure 4

The value of ${\kappa }_{\mathrm{tr}}$ from 11 data sets of various lengths from Modified Julian Day 54 356 to 54 634. The value is extracted from fits to data using demodulated least squares at ${\omega }_R\pm {\omega }_{\oplus }$. The error bars represent the standard error, and the lengths represent the duration of the data set. In general the longer the duration the smaller the standard error. By taking the weighted average over the multiple data sets the value of $-0.3\pm 3\times {10}^{-7}$ is obtained, which is shown to the right of the figure.Reuse & Permissions

Figure 5

Left. The time trace of the mixer output voltage over a 12.5-day period of continuous operation while the experiment was stationary. Intermittent noisy periods are apparent. The phase noise spectral density of the quiet period shown between the dashed lines is shown in Fig. 2. Right. The time trace of the mixer output voltage over a 5.8-day period of continuous operation while the experiment was rotating. Intermitent noisy periods are apparent (dark regions), which were vetoed in the final analysis. The phase noise spectral density of the quiet period shown between the dashed lines is shown in Fig. 2.Reuse & Permissions