Frequency Comb Assisted Diode Laser Spectroscopy for Measurement of Microcavity Dispersion

While being invented for precision measurement of single atomic transitions, frequency combs have also become a versatile tool for broadband spectroscopy in the last years. In this paper we present a novel and simple approach for broadband spectroscopy, combining the accuracy of an optical fiber-laser-based frequency comb with the ease-of-use of a tunable external cavity diode laser. This scheme enables broadband and fast spectroscopy of microresonator modes and allows for precise measurements of their dispersion, which is an important precondition for broadband optical frequency comb generation that has recently been demonstrated in these devices. Moreover, we find excellent agreement of measured microresonator dispersion with predicted values from finite element simulations and we show that tailoring microresonator dispersion can be achieved by adjusting their geometrical properties

Health-Related Quality of Life, Subjective Health Complaints, Psychological Distress and Coping in Pakistani Immigrant Women With and Without the Metabolic Syndrome: The InnvaDiab-DEPLAN Study on Pakistani Immigrant Women Living in Oslo, Norway

The increasingly high number of immigrants from South-East Asia with The Metabolic Syndrome (MetS) is an important challenge for the public health sector. Impaired glucose is essential in MetS. The blood glucose concentration is not only governed by diet and physical activity, but also by psychological distress which could contribute to the development of MetS. The aim of this study is to describe health-related quality of life, subjective health complaints (SHC), psychological distress, and coping in Pakistani immigrant women, with and without MetS. As a part of an randomized controlled intervention study in Oslo, Norway, female Pakistani immigrants (n = 198) answered questionnaires regarding health related quality of life, SHC, psychological distress, and coping. Blood variables were determined and a standardized oral glucose tolerance test was performed. The participants had a high score on SHC and psychological distress. About 40% of the participants had MetS, and this group showed significantly lower general health, lower physical function, and more bodily pain, than those without MetS. Those with MetS also had more SHC, depressive symptoms, higher levels of somatisation, and scored significantly lower on the coping strategy of active problem solving. Pakistani immigrant women seem to have a high prevalence of SHC and psychological distress, especially those with MetS

Quantum cascade laser frequency stabilisation at the sub-Hz level

Quantum Cascade Lasers (QCL) are increasingly being used to probe the mid-infrared "molecular fingerprint" region. This prompted efforts towards improving their spectral performance, in order to reach ever-higher resolution and precision. Here, we report the stabilisation of a QCL onto an optical frequency comb. We demonstrate a relative stability and accuracy of 2x10-15 and 10-14, respectively. The comb is stabilised to a remote near-infrared ultra-stable laser referenced to frequency primary standards, whose signal is transferred via an optical fibre link. The stability and frequency traceability of our QCL exceed those demonstrated so far by two orders of magnitude. As a demonstration of its capability, we then use it to perform high-resolution molecular spectroscopy. We measure absorption frequencies with an 8x10-13 relative uncertainty. This confirms the potential of this setup for ultra-high precision measurements with molecules, such as our ongoing effort towards testing the parity symmetry by probing chiral species