Overview of the Characteristics of Micro- and Nano-Structured Surface Plasmon Resonance Sensors

The performance of bio-chemical sensing devices has been greatly improved by the development of surface plasmon resonance (SPR) based sensors. Advancements in micro- and nano-fabrication technologies have led to a variety of structures in SPR sensing systems being proposed. In this review, SPR sensors (from typical Kretschmann prism configurations to fiber sensor schemes) with micro- or nano-structures for local light field enhancement, extraordinary optical transmission, interference of surface plasmon waves, plasmonic cavities, etc. are discussed. We summarize and compare their performances and present guidelines for the design of SPR sensors

Experimental demonstration of enhancing pump absorption rate in cladding-pumped ytterbium-doped fiber lasers using pump-coupling long-period fiber gratings

A long-period fiber grating (LPFG) was inscribed in a single-mode fiber and was spliced with a ytterbium (Yb)-doped double-clad fiber in order to couple pump radiation of the inner cladding into the core in a cladding-pumped fiber laser. The use of an LPFG permits a partial core-pumping scheme in a cladding pumping fiber laser because a portion of the pump radiation can be coupled to the core by LPFG. The enhancement of the pump absorption of a Yb-doped cladding-pumped fiber laser as the result of pump coupling by LPFG was 35%, and the maximal output power increased by up to 55% when a 20W pump source is used

Liquid-crystal-cladding fiber Bragg gratings with electrically controllable polarization-dependent characteristics

An electrically controllable fiber Bragg grating (FBG) with polarization-dependent characteristics is described. The optic axis of a liquid crystal (LC) can be rearrangeable by means of external electric fields, which results in the change of an effective refractive index of an LC. The reflectivity and Bragg wavelength of an LC-cladding FBG can be controlled according to the refractive index of surrounding region of the fiber which is determined by the refractive index of the LC-cladding. The tuning ranges of the LC-cladding FBG were ~4.6 dB of the reflectivity and ~0.3 nm of Bragg wavelength based on unpolarized light, respectively, and polarization isolation of 1.5 dB was achieved at 100 V(p-p) based on polarized light

Guidelines for Mobile Laboratories for Molecular Diagnostic Testing of COVID-19

With the rapid spread of the coronavirus disease (COVID-19), the need for rapid testing and diagnosis and consequently, the demand for mobile laboratories have increased. Despite this need, there are no clear guidelines for the operation, maintenance, or quality control of mobile laboratories. We provide guidelines for the operation, management, and quality control of mobile laboratories, and specifically for the implementation and execution of COVID-19 molecular diagnostic testing. These practical guidelines are primarily based on expert opinions and a laboratory accreditation inspection checklist. The scope of these guidelines includes the facility, preoperative evaluation, PCR testing, internal and external quality control, sample handling, reporting, laboratory personnel, biosafety level, and laboratory safety management. These guidelines are useful for the maintenance and operation of mobile laboratories not only in normal circumstances but also during public health crises and emergencies.N