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The linewidth of a gallium antimonide-based laterally-coupled 2.05 µm DFB laser emitting 40 mW of power at 9 C is measured. The measured linewidth is 1.7 MHz for 500 ms and 1.4 MHz for 10 ms observation time, respectively. The combination of high power and low frequency jitter makes this laser useful for detecting CO2 in air in both in-situ and remote sensing applications. The linewidth measurement is also discussed. [ABSTRACT FROM AUTHOR]

Ridge waveguide type-I quantum-well GaSb-based diode lasers operating at room temperatures in the spectral region near 3.15 µm have been designed and fabricated. The laser active region comprises three InGaAsSb quantum-wells embedded into quinary AlInGaAsSb barrier material to promote carrier confinement. Lasers generate 9 mW of continuous-wave output power at 3.16 µm in a diffraction limited beam at 20°C. Devices operate in continuous-wave regime up to 40°C producing above 1 mW of power at wavelength above 3.2 µm. [ABSTRACT FROM AUTHOR]

The article focuses on the development of high power fibre-coupled distributed feedback (DFB) laser sources for atmospheric sensing lidar transmitters. Noted is the ability of seed laser emission wavelength to be locked to reference gas cell minimising wavelength drift and jitter. It is expected that prototype lasers will be integrated into the airborne lidar carbon dioxide profiling campaigns.

The interband cascade laser (ICL) is an ideal candidate for low-power mid-infrared frequency comb spectroscopy. In this work, we demonstrate that its intracavity second-order optical nonlinearity induces a coherent up-conversion of the generated mid-infrared light to the near-infrared through second-harmonic and sum-frequency generation. At 1.8 µm, 10 mW of light at 3.6 µm convert into sub-nanowatt levels of optical power, spread across 30 nm of spectral coverage. The observed linear-to-nonlinear conversion efficiency exceeds ${3\;{\unicode{x00B5} {\rm W/W}}^2}$3µW/W 2 in continuous wave operation. We use a dual-band ICL frequency comb source to characterize water vapor absorption in both spectral bands.

Two semiconductor optical frequency combs, consuming less than 1 W of electrical power, are used to demonstrate high-sensitivity mid-infrared dual-comb spectroscopy in the important 3-4 μm spectral region. The devices are 4 mm long by 4 μm wide, and each emits 8 mW of average optical power. The spectroscopic sensing performance is demonstrated by measurements of methane and hydrogen chloride with optical multi-pass cell sensitivity enhancement. The system provides a spectral coverage of 33  cm -1 (1 THz), 0.32  cm -1 (9.7 GHz) frequency sampling interval, and peak signal-to-noise ratio of ∼100 at 100 μs integration time. The monolithic design, low drive power, and direct generation of mid-infrared radiation are highly attractive for portable broadband spectroscopic instrumentation in future terrestrial and space applications.

While whispering gallery mode resonators are well known for their low acceleration sensitivity, there has not been much published experimental research on the subject. We performed environmental sensitivity tests of a 2 μm semiconductor distributed feedback (DFB) laser, self-injection locked to a high-Q crystalline whispering gallery mode resonator. Measured acceleration sensitivity of the laser is below 5×10 -11   g -1 in the 1-200 Hz frequency bandwidth and thermal sensitivity does not exceed 12  MHz/°C. The laser's frequency noise is below 50  Hz/Hz 1/2 at 10 Hz, reaching 0.4  Hz/Hz 1/2 at 400 kHz. The instantaneous linewidth of the laser is improved by nearly 4 orders of magnitude compared to the free-running DFB laser and is measured to be 50 Hz at 0.1 ms measurement time. The Allan deviation of the laser frequency is on the order of 10 -9 from 1 to 1000 s. All these features make the laser attractive for metrology applications involving low-noise 2 μm seed lasers.

Background: In 2013 the Chilean regulatory sanitary agency issued a warning concerning dose adjustment and use restriction to avoid severe adverse effects of metoclopramide such tardive dyskinesia., Aim: To study dyskinesia type adverse effects in a population using metoclopramide., Material and Methods: A cross sectional observational study was conducted among patients pertaining to palliative care and diabetes mellitus programs and consuming 10 mg/day or more of metoclopramide. Patients were interrogated looking for extrapiramidal signs and symptoms using a questionnaire validated by two neurologists., Results: In 40% of diabetic patients with gastroparesia and 35% of palliative care patients, extrapyramidal adverse reactions to metoclopramide were suspected. Palliative Care patients suffered the largest number of adverse events. The period of use and individual doses of the drug were largely above Chilean regulatory agency recommendations in all cases., Conclusions: A significant number of patients using metoclopramide could experience extrapyramidal adverse reactions.

Since their inception, optical frequency combs have transformed a broad range of technical and scientific disciplines, spanning time keeping to navigation. Recently, dual comb spectroscopy has emerged as an attractive alternative to traditional Fourier transform spectroscopy, since it offers higher measurement sensitivity in a fraction of the time. Midwave infrared (mid-IR) frequency combs are especially promising as an effective means for probing the strong fundamental absorption lines of numerous chemical and biological agents. Mid-IR combs have been realized via frequency down-conversion of a near-IR comb, by optical pumping of a micro-resonator, and beyond 7 μm by four-wave mixing in a quantum cascade laser. In this work, we demonstrate an electrically-driven frequency comb source that spans more than 1 THz of bandwidth centered near 3.6 μm. This is achieved by passively mode-locking an interband cascade laser (ICL) with gain and saturable absorber sections monolithically integrated on the same chip. The new source will significantly enhance the capabilities of mid-IR multi-heterodyne frequency comb spectroscopy systems.

Working memory (WM) deficits are often reported in patients with Bipolar Disorder (BD). However, it is not clear about the nature of these WM deficits (update or serial order processes) and their association with each BD states (euthymic, mania, and depressive). This review investigated the association between BD patient's states and the functioning of WM components. For this purpose, we carried out a systematic review fulfilling a search in the databases Medline, Scopus, SciELO, and Web of Science using specific terms in the abstracts of the articles that generated 212 outcomes in the restricted period from 2005 to 2016. Twenty-three papers were selected, completely read, and analyzed using PICOS strategy. The mood episodes predicted deficits in different components of WM in BD patients (the phonological loop or visuospatial sketchpad) and were associated with different WM processes (updating and serial recall). Lower cognitive scores persist even in remission of symptoms. This result suggests that WM deficit apparently is stage-independent in BD patients. Furthermore, findings suggest that the neutral point on Hedonic Detector component of WM could be maladjusted by BD.

We report on the stabilization of a high-power distributed feedback (DFB) semiconductor laser operating at 2.05 μm wavelength, using a crystalline whispering gallery mode microresonator. The laser's frequency noise is measured to be below 100  Hz/Hz 1/2 at Fourier frequencies ranging from 10 Hz to 1 MHz. The instantaneous linewidth of the laser is improved by four orders of magnitude compared with the free-running DFB laser, and is measured to be 15 Hz at 0.1 ms measurement time. The integral linewidth approaches 100 Hz. The stabilized DFB laser is integrated with a polarization maintaining output fiber and an integrated optical isolator.