Journal of Lasers, Optics & Photonics

For an extended time, Fiber Bragg Grating (FBG) based sensors were intensively studied for application in engineering structure, like bridges, dams, etc. Recently, thanks to the benefits of small volume, light weight, anti-electromagnetic interference, anti-oil corrosion, and multiple measuring points in one glass fiber, FBG-based sensors have attracted many interests and been widely investigated by researchers and engineers in industrial filed. Our research focuses on dynamical monitoring and diagnoses of mechanical systems supported distributed fiber Bragg grating sensors.

Defect reduction is usually a crucial topic for the researches of epitaxy improvement. Commercial dome-shaped patterned-sapphire substrates (CDPSS) had been designed to tackle this problem during the epitaxy of gallium nitride (GaN), and that they did reduce the density of defect considerably. So as to reveal the veiled mechanism of defect reduction, we had executed Raman scattering and X-ray diffraction (XRD) measurements on various samples with different growth time to verify the behaviour of defects during epitaxy 1. The results of etch pits density (EPD) had been included, too.

Bright quantum states of sunshine are progressively a topic of intense research due to the very fact that these states can provide much stronger interactions with matter and with one another than the fait (microscopic) stets of sunshine. As they contain large numbers of photons, they resemble with classical systems. Thus it becomes essential to research to what extent such states exhibit “quantumness”. Microscopic Bell states, which are four modes squeezed vacuum states, are one such bright system containing typically 106 photons per pulse. We wish to implement a way namely ‘three-dimensional quantum polarization tomography’ for characterization of polarization and squeezing features of those states.

As it is documented, glass fiber lasers are often used as sensor elements on their own, which supply new possibilities for developing high-performance sensors with compact size when needed and reduced complexity. variety of distributed and point glass fiber lasers are often developed for various sensing applications counting on the technology wont to generate the laser and also counting on the physical or chemical parameter under evaluation. On the opposite hand, glass fiber laser sensors are a number of the foremost reliable and robust laser systems. Taking care of the planning and manufacturing process required to ensure a high level of reliability, inhospitable environments are often easily monitored even once they operate in such harsh conditions like sensing in high-voltage or high-power machinery, or in explosive environments. Also, the increasing interest about structural health monitoring systems has helped to boost the event of novel glass fiber laser technologies for sensing applications. More and more lately developed fiber technologies bring a superior performance to fiber-optic sensing networks.

Broadband tuning of MIR-infrared radiation from 3 to 10 μm may be a very promising way for spectroscopic study of gaseous, liquid, or solid species or intermixtures. We report a quick broadband tunable IR-light source supported the mixture of a quantum-cascade-laser and micro-opto-electro-mechanical systems (MOEMS) with integrated diffractive grating. This idea unites the benefits of broadband sources with the benefits of coherent laser sources during a miniaturized setup. The grating is processed inline within the MOEMS production process by non-isotropic etching.