Complex direct comb spectroscopy with a virtually imaged phased array

LetterAbstract not availableSarah K. Scholten, James D. Anstie, Nicolas Bourbeau Hébert, Richard T. White, Jérôme Genest, and Andre N. Luite

Dichroic two-photon rubidium frequency standard

We demonstrate an optical frequency standard based on the 5S1/2→5D5/2 two-photon transition of rubidium. The transition is interrogated in a Doppler-free arrangement by two lasers at 780 and 776 nm, with the sum frequency of the two lasers locked to the two-photon transition. We measure the fractional frequency stability of the frequency standard to be 1.5×10−13 at 1 s, reaching 4.9×10−14 at approximately 100s, by comparison with an optical frequency comb. Performance limitations are presented and a clear pathway to an order-of-magnitude improvement is discussed. This platform has the potential to deliver a compact, robust standard for commercial and industrial applications.C. Perrella, P.S. Light, J.D. Anstie, F.N. Baynes, R.T. White and A.N. Luite

Exciting traveling waves in high Q structures using microstrip

International audienc

Whispering modes in anisotropic and isotropic dielectric spherical resonators

International audienc

High-Q frequency temperature compensated solid nitrogen cooled resonator oscillators: first results

International audienc

High-Q frequency temperature compensated solid nitrogen cooled resonator oscillators: first results.

International audienc

Handheld probe for quantitative micro-elastography

16 pags., 7 figs., 1 tab.Optical coherence elastography (OCE) has been proposed for a range of clinical applications. However, the majority of these studies have been performed using bulky, lab-based imaging systems. A compact, handheld imaging probe would accelerate clinical translation, however, to date, this had been inhibited by the slow scan rates of compact devices and the motion artifact induced by the user’s hand. In this paper, we present a proof-of-concept, handheld quantitative micro-elastography (QME) probe capable of scanning a 6 × 6 × 1 mm volume of tissue in 3.4 seconds. This handheld probe is enabled by a novel QME acquisition protocol that incorporates a custom bidirectional scan pattern driving a microelectromechanical system (MEMS) scanner, synchronized with the sample deformation induced by an annular PZT actuator. The custom scan pattern reduces the total acquisition time and the time difference between B-scans used to generate displacement maps, minimizing the impact of motion artifact. We test the feasibility of the handheld QME probe on a tissue-mimicking silicone phantom, demonstrating comparable image quality to a bench-mounted setup. In addition, we present the first handheld QME scans performed on human breast tissue specimens. For each specimen, quantitative micro-elastograms are co-registered with, and validated by, histology, demonstrating the ability to distinguish stiff cancerous tissue from surrounding soft benign tissue.Australian Research Council (ARC); Department of Health, Western Australia; Cancer Council, Western Australia; OncoRes Medical