We present a tilted fiber Bragg grating (TFBG)-based optic sensor for the simultaneous measurement of liquid level and temperature. Due to different responses cladding modes core mode in TFBG spectrum temperature changes, both values can be measured independently. The examined 3.5° exhibits linear level, as well temperature, sensitivities -0.456 ± 0.009 dB/mm 11.4 0.2 pm/°C, respectively. In addition, greater applicability is proposed liquids having lower refractive indexes using with tilt...

A novel concept of a Fabry-Perot (F-P) cavity composed two linearly chirped fiber Bragg gratings written in thermally fused taper is presented. Both are counter-directional chirp configuration, where chirps resulting from the optical profile and increasing grating periods cancel each other out, forming high-quality F-P resonator. new strain-sensing mechanism proposed presented structure, which based on strain-induced detuning Due to different strain temperature responses cavity, resonator...

Composite structures exhibiting a periodic arrangement of building blocks can be found in natural systems at different length scales. Recreating such artificial composites using the principles self-assembly has been great challenge, especially for 1D microscale systems. Here, we present purposely designed composite material consisting gold nanoparticles and nematic liquid crystal matrix that ability to self-create structure form one-dimensional photonic lattice through phase separation...

In this paper, spectrally tailored tapered chirped fiber Bragg gratings (TCFBGs) are considered for use as strain sensors. Both were written in fused optical using linearly co-directional and counter-directional chirp configurations. Theoretical numerical analysis well experimental verification of the influence applied on spectral width both TCFBG structures carried out. The results show that TCFBGs exhibit monotonic response over wide operating range force. Compared with standard FBG...

Efficient continuous-wave laser operation at 2.982 μm is achieved with a Dy <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3±</sup> :fluoride fiber pumped using an inhouse-built 1.1 ytterbium (III) laser. The output power reached 554 mW, maximum slope efficiency of 18% respect to the launched pump power. Additionally, measured spontaneous luminescence within visible wavelength range, under pumping, presented and attributed excited state...

Different methods allowing for creating optical waveguides with liquid-crystal (LC) cores, in which molecules form periodic patterns precisely controlled periods, are reported. The first one is based on reversible photoalignment high-resolution selective illumination and allows to control the period of LC inside silica microcapillaries. second method employs microstructures formed PDMS, obtain both: LC-core a set specially designed microelectrodes used reorientation molecules. Using both...

Hollow-core optical fibers (HCFs) have unique properties like low latency, negligible nonlinearity, wide low-loss spectrum, up to 2100 nm, the ability carry high power, and potentially lower loss then solid-core single-mode (SMFs). These features make them very promising for communication networks similar applications. However, this class of is still in development. Current applications are almost exclusively limited low-latency data links High-Speed Trading (HST); other uses trial stage...

A versatile numerical model for spectral transmission/reflection, group delay characteristic analysis, and design of tapered fiber Bragg gratings (TFBGs) is presented. This approach ensures flexibility with defining both distribution refractive index change the (including apodization) shape taper profile. Additionally, sensing tunable dispersion properties TFBGs were fully examined, considering strain-induced effects. The presented approach, together Pareto optimization, also used to best...

Abstract In this paper research on the development of fiber Bragg grating (FBG) technology which has been conducted at Institute Electronic Systems (IES), Warsaw University Technology (WUT) since 2004 is presented. particular directions in advanced set-ups employing phase mask inscription scheme are discussed and supported with descriptions structures designed fabricated use laboratory stages constructed IES. The novelty presented solutions based combination numerous techniques external...

In this paper, the application of a fiber Bragg grating written in highly birefringent side-hole elliptical core optical for two-axial strain measurement is presented. Hybrid structures achieved by combining large side-holes and result very high birefringence 1 × 10−3 thus initial peak spectral separation 1.16 nm, as well transverse force sensitivity, up to 650 pm/(N/mm) or even −1150 pm/(N/mm), depending on orientation with respect applied force. Due ~22 %m/m GeO2 concentration being...

A new concept for an optical fiber inclinometer based on tapered Bragg grating (TFBG) is presented. The sensor was characterized by the experimental measurement of dependence inclination angle spectral response in fluctuating temperature conditions. research showed that TFBG made it possible to simultaneously measure both and temperature, operate as a insensitive 0°-90° tilt sensor, different interrogation regime. Inscription FBG section offered not only miniaturization, but also possibility...

In this paper, a theoretical analysis of recently developed tapered chirped fiber Bragg gratings (TCFBG) written in co-directional and counter-directional configurations is presented. particular, the effects synthesis chirps resulting from both fused taper profile linearly fringe pattern induced refractive index changes within core are extensively examined. For purpose, numerical model based on transfer matrix method (TMM) coupled mode theory (CMT) was for such grating. The impact TCFBG...

In this paper there are described setup for modification of exposure time in fiber Bragg gratings fabrication with using scanning phase mask method. Using laboratory stage we able to write uniform, apodized and chirped gratings. Depending on grating length it is possible various attenuation wavelength. Also, change wavelength, obtain by linear gradient post-processing respectively.

In this paper the numerical results of tapered fiber Bragg gratings modeling are shown. Presented model, based on coupled mode theory and transfer matrix method for gratings, gives highly accurate reflection width evaluation. Few simulations were made three different configurations structures, as well comparison between theoretical experimental results.

In this paper a new concept of human breath detection by means fiber Bragg grating (FBG) based temperature sensor is reported. presented approach, exhaled air directly measured FBG, and its wavelength changes allow for determine breathing rate. Experimental results comparison the FBG with electronic one, show significant advantages our solution, especially when faster and/or plate detected. Another advantage proposed rate ability to work in high electromagnetic field environment, example...

Fabrication of fiber Bragg gratings using phase mask method, despite the substantial advantages, has a significant drawback. In this technique, period determines wavelength, and thus limits possibilities shaping its spectral characteristics. The paper presents possibility modifying transmission reflection spectra written in thermally tapered optical complex UV irradiation through uniform mask. Structures with two wavelengths narrow band characteristics were achieved by amplitude refractive...

In this paper the comparative study of spectral transmission characteristics tilted Bragg gratings made using uniform phase mask and chirped are presented. Results focused on low tilt angles with special interest cladding modes behavior. The characteristic shape for simultaneously point out its potential applications as amplitude discriminator in fiber sensing gain flattening element EDFA.

A nanostructured core silica fiber with active and photosensitive areas implemented within the is demonstrated. The photosensitivity, passive properties of can be independently shaped this new approach. We show that discrete local doping ions in form nanorods allow to obtain effective laser action as case continuous distribution core. Co-existing nanostructure germanium doped determine single-mode performance inscription highly efficient Bragg grating over entire area. Each do not degrade...

In this paper, the influence of structural modifications on basic quasi-periodic (QP) photonic crystals (PhC’s) self-similarity feature in their spectral responses is examined. Investigated are chosen based a present knowledge QP crystals, and classified according to structure. One considered for calculations concatenation, Fibonacci It characterizes with self-similar spectra its different orders, which means, that shape repeats itself can be partially identical orders crystal. The were also...

A laboratory realization of an actively Q-switched Dy <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped fluoride fiber laser operating near 3.0 μm is reported. Two cavities were realized: one based on 1000 ppm :ZBLAN and 2000 fiber. With the cavity a record high peak power 200 W was achieved with 17 μJ pulse energy 84.5 ns duration. Moreover, short duration 74 using composed

A new fabrication method of apodized diffractive optical elements is proposed. It relies on using high energy beam sensitive glass as a halftone mask for variable diffraction efficiency phase masks generation in resist layer. The presented technology especially effective mass production. Although an amplitude required, it then repeatedly used single shot projection photolithography, which much simpler and less laborious than the direct variable-dose pattern writing. Three prototypes were...

A new simple and versatile method for inscribing fiber Bragg gratings with an arbitrarily chosen wavelength is presented. Owing to the optimization of irradiation process application phase mask a properly matched chirp, offers ability adjust FBG resonance adjustment within range tens nanometer. However; resulting grating has chirp; its spectral properties closely resemble those uniform one, which explains why such are called quasi-uniform (QUFBGs). Optimization inscription involved two...