Two simple external cavity diode laser designs using fibre pigtailed gain chips are tested and their properties compared with a high end DBR fibre laser. These ECDLs demonstrate a FWHM linewidth as low as 5.2kHz with a fitted Lorentzian FWHM linewidth as low as 1.6kHz. Tuning ranges of 200nm covering 1420nm to 1620nm were demonstrated. To the best of our knowledge these are the narrowest linewidth and most broadly tunable external cavity diode lasers reported to date. The improvement in linewidth is attributed to greatly enhanced acoustic isolation allowed by using fiber coupled gain chips and by replacing kinematic mounts with a pair of rotatable wedges for cavity alignment which eliminates acoustic resonances. A detailed description and discussion of techniques used to characterize the frequency noise and linewidths of these lasers is provided.
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http://dx.doi.org/10.1364/OE.22.010642 | DOI Listing |
Nature
January 2025
Department of Chemistry, The University of Hong Kong, Hong Kong SAR, China.
Mimicking the superstructures and properties of spherical biological encapsulants such as viral capsids and ferritin offers viable pathways to understand their chiral assemblies and functional roles in living systems. However, stereospecific assembly of artificial polyhedra with mechanical properties and guest-binding attributes akin to biological encapsulants remains a formidable challenge. Here we report the stereospecific assembly of dynamic supramolecular snub cubes from 12 helical macrocycles, which are held together by 144 weak C-H hydrogen bonds.
View Article and Find Full Text PDFJ Acoust Soc Am
January 2025
Department of Mechanical Engineering, Binghamton University, Binghamton, New York 13902, USA.
A study is presented of a method for creating an acoustic flow sensor that is generally compatible with current silicon microfabrication processes. An aim of this effort is to obtain a design consisting of a minimal departure from the existing designs employed in mass-produced silicon microphones. Because the primary component in all of these microphones is the cavity behind the pressure-sensing diaphragm, we begin with a study of the acoustic particle velocity within a cavity in a planar surface.
View Article and Find Full Text PDFBiomedicines
November 2024
Department of Neurosurgery, King's College Hospital NHS Foundation Trust, London SE5 9RS, UK.
Background/objectives: 5-aminulevulinic acid (5-ALA)-guided surgery for high-grade gliomas remains a challenge in neuro-oncological surgery. Inconsistent fluorescence visualisation, subjective quantification and false negatives due to blood, haemostatic agents or optical impediments from the external light source are some of the limitations of the present technology.
Methods: The preliminary results from this single-centre retrospective study are presented from the first 35 patients operated upon with the novel Nico Myriad Spectra System©.
Adv Sci (Weinh)
January 2025
School of Fashion and Textiles, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, China.
Acting as the interface between the human body and its environment, clothing is indispensable in human thermoregulation and even survival under extreme environmental conditions. Development of clothing textiles with prolonged passive temperature-adaptive thermoregulation without external energy consumption is much needed for protection from thermal stress and energy saving, but very challenging. Here, a temperature-adaptive thermoregulation filament (TATF) consisting of thermoresponsive vacuum cavities formed by the temperature-responsive volume change of the material confined in the cellular cores of the filament is proposed.
View Article and Find Full Text PDFPlant Dis
January 2025
University of Florida Tropical Research and Education Center, Plant Pathology, 1615 SE 23rd Way, Homestead, Florida, United States, 33031-3314;
The commercial production of passion fruit is geographically limited (California, Florida, and Hawaii), but the development of cold-tolerant varieties could expand it beyond warm-climate states (Stafne et.al. 2023).
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