We present the first results from a rotating Michelson-Morley experiment that uses two orthogonally orientated cryogenic sapphire resonator oscillators operating in whispering gallery modes near 10 GHz. The experiment is used to test for violations of Lorentz invariance in the framework of the photon sector of the standard model extension (SME), as well as the isotropy term of the Robertson-Mansouri-Sexl (RMS) framework. In the SME we set a new bound on the previously unmeasured kappa(ZZ)(e-) component of 2.1(5.7) x 10(-14), and set more stringent bounds by up to a factor of 7 on seven other components. In the RMS a more stringent bound of -0.9(2.0) x 10(-10) on the isotropy parameter, P(MM) = delta-beta + 1 / 2 is set, which is more than a factor of 7 improvement.

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We review the techniques used in the design and construction of cryogenic sapphire oscillators at the University of Western Australia over the 18 year history of the project. We describe the project from its beginnings when sapphire oscillators were first developed as low-noise transducers for gravitational wave detection. Specifically, we describe the techniques that were applied to the construction of an interrogation oscillator for the PHARAO Cs atomic clock in CNES, in Toulouse France, and to the 2006 construction of four high performance oscillators for use at NMIJ and NICT, in Japan, as well as a permanent secondary frequency standard for the laboratory at UWA. Fractional-frequency fluctuations below 6 x 10(-16) at integration times between 10 and 200 s have been repeatedly achieved.

We present new results from our test of Lorentz invariance, which compares two orthogonal cryogenic sapphire microwave oscillators rotating in the lab. We have now acquired over 1 year of data, allowing us to avoid the short data set approximation (less than 1 year) that assumes no cancellation occurs between the eÿ and o parameters from the photon sector of the standard model extension. Thus, we are able to place independent limits on all eight eÿ and o parameters. Our result represents up to a factor of 10 improvement over previous nonrotating measurements (which independently constrained seven parameters) and is a slight improvement (except for ZZ eÿ ) over results from previous rotating experiments that assumed the short data set approximation. Also, an analysis in the Robertson-Mansouri-Sexl framework allows us to place a new limit on the isotropy parameter P MM ÿ 1 2 of 9:48:1 10 ÿ11 , an improvement of a factor of 2.

We report on the development of a sapphire cryogenic microwave resonator oscillator with long-term fractional frequency stability of 2 × 10 -17 √τ for integration times τ >10 3 s and a negative drift of about 2.2 × 10 -15 /day. The short-term frequency instability of the oscillator is highly reproducible and also state-of-the-art: 5.6 ×10 -16 for an integration time of τ ≈ 20 s.