A fiber-optic interferometric probe based on a two-mode fiber (TMF) is proposed and demonstrated for measuring the thermo-optic coefficients (TOCs) of liquid samples. The can be simply fabricated by fusion-splicing short piece TMF to lead single mode (SMF) with small lateral offset, which makes interference between LP(01) LP(02) modes. sensing responses temperature surrounding refractive index (SRI) have been experimentally investigated show capability simultaneous measurements; phase change...

PLQY and charge carrier mobility of perovskite quantum QDs were enhanced by the optimization crystallinity solid-state ligand exchange.

We have found that the emission spectrum of phosphors measured in powder state differs from for a single phosphor. When is adopted an optical simulation, simulated properties e.g., correlated color temperature, rendering index, and chromaticity coordinates, show remarkable discrepancy those fabricated LED package. However, significantly improved when low concentration phosphor silicone binder employed. suggest originates absorption Stokes shifted light by

A laser-sintered die adhesive based on silver nanoparticles (AgNPs) is used to fabricate high-power light-emitting diodes (LEDs). Following the optimization of laser power and irradiation time, sintering AgNPs without any organic binder shows comparable adhesion property that conventional LED chip bonding layer with silicone silver-loaded epoxy adhesives. Among tested LEDs, devices using AgNP exhibit best performance in both efficiency reliability, which are governed by thermal conducting...

The projection-type dental lighting based on the remote phosphor light-emitting diode (LED) package is designed to enhance uniformity of illuminance and correlated color temperature (CCT) a target plane remove glare in eyes patient. This enables dentists illuminate effectively patient's mouth by increasing inner area (50 mm×25 mm) described ISO 9680. optical module comprised LED lens modeled satisfy wider than 100 mm×50 mm over 5,000 lx per module. fabricated prototype contains four modules,...

We propose and demonstrate a fiber Bragg grating (FBG) sensor network employing the code division multiple access (CDMA) technique to identify information from individual sensors. To detect without considering time delays between sensors, sliding correlation method is applied, in which two different signals with same pseudo-random binary sequence (PRBS) pattern, but slightly frequencies, are applied source detector sides. Moreover, for domain detection, wavelength-to-time conversion using...

An optical signal-to-noise ratio (OSNR) monitoring technique using a cascaded long-period fiber grating with tunable phase shifter is proposed for non return-to-zero on-off-keying (NRZ-OOK) and differential shift keying (DPSK) signals. This method based on two key points: first, the long period (CLPG) acts as an delay interferometer (ODI) by Mach-Zehnder configuration consisting of core cladding modes inside CLPG. Secondly, optically Yb(3+) doped (YDF) inserted between The modulated signal...

The aim of this paper is to improve the color temperature uniformity per view angle a white light-emitting diode (LED) by utilizing silicone microspheres (SMSs). 97.5 ° when using encapsulant alone, and it increases 108 with use 0.1 wt% SMSs. With 0.3 SMSs added that contains 7 phosphor, deviation improves from 1300 167 K. A design experiments used quantitatively analyze effect on reduction amount phosphor required, actual samples are fabricated based results compare their characteristics....

The effects of the refractive index an encapsulant on light-extraction efficiency (LEE) white light-emitting diodes (LEDs) are studied. A dome-type blue LED with a high-refractive-index (HRE) shows higher LEE compared to that low-refractive-index (LRE). In flat-type surface-mounted device (SMD) package, however, LRE than HRE. These results stem from differences in total internal reflection at interfaces between and air. SMD interface chip HRE is LRE, whereas air lower simulation based Monte...

We propose the in-band optical signal-to-noise-ratio (OSNR) monitoring method using a Mach-Zehnder interferometer. This interferometer is implemented by inserting piece of Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped fiber (YDF) between two strands thermally expanded core (TEC) fibers: former to give phase delay one arms (core and cladding modes YDF) latter arm paths. By TEC fibers split input signal combine again, fringe...

We propose and demonstrate a long-reach wavelength division multiplexed-passive optical networks (WDM-PON) based on reflective semiconductor amplifiers (RSOAs) with easy maintenance of the source. Unlike previous studies proposed WDM-PON uses two RSOAs: one for wavelength-selected light generation to provide constant seed second RSOA, other active external modulation. This method is free from intensity-fluctuated power penalties inherent directly modulated single-RSOA sources, making...

A simple and feasible techniques for ultra-wideband (UWB) triplet pulse generation based on gain switching of self-seeded reflective semiconductor optical amplifier (RSOA) is proposed demonstrated. The system consisted RSOA, erbium doped fiber laser (EDFA), two Bragg gratings (FBGs), balanced photo detector (BPD). short train which has a low timing jitters width was generated RSOA. Gaussian well match the Federal Communications Commission (FCC) mask in frequency domain. Generated UWB...

Poly-dispersed silver nanoparticles (AgNPs) were synthesized through a polyol reaction and separated by centrifuging process to control the target plasmon resonance frequency. When ratio between polar side group of polyvinyl pyrrolidone ions is less than 1, AgNPs various sizes broad extinction spectrum can be obtained single process. Following physical separation poly-dispersed AgNPs, both size distribution tuned depending on speed. Fitting measured absorption using Mie calculation confirms...

When the emission spectrum of powder state is adopted, simulated optical properties show a remarkable discrepancy from those fabricated LED package. We suggest that originates absorption Stokes shifted light by phosphor.

Optical characteristics including the radiant flux and viewing angle of UV LEDs were investigated according to both silicone encapsulants with different refractive indexes lens shapes. Lead frame was fabricated using enhanced heat dissipation a slug structure reflector based on EMC(Epoxy Mold Compound) material. Four types shapes designed their optical depending index evaluated. The maximum can be achieved when height are 1.32mm 1.08mm for low high indexes, respectively. Depending...

There has been a critical issue in optical simulation of phosphors LEDs due to their light-reabsorption properties. To improve the accuracy modeling for white LED package, we utilized spectrum data phosphor-dispersed encapsulant film instead phosphor powder. By measuring packages with green and red phosphors, maximum difference between experimental results color temperature, rendition index number coordinate corresponds ΔT=95K, ΔRa=1.7 Δxy=0.007, respectively. Based on those results,...

본 논문은 코드 분할 다중방식을 이용하여 외부로부터 선박에 가해지는 변형 및 온도 변화를 모니터링 할 수 있는 광섬유 브라그 격자 (FBG) 기반의 센서 네트워크를 제안하였다. 변형이 발생 하거나 온도의 변화가 일어날 때 FBG는 본래 가지고 중심 파장이 이동하며 이는 외부 크기에 비례하여 증가된다. 중심파장의 변화량을 측정함으로써 센서에 변형이나 크기를 알 있다. 제안된 네트워크는 코드분할 이용하였으며 광원에서 발생되는 신호를 직접 변조하여, 변조된 센서로 보내고 센서로부터 돌아오는 검출하여 상태를 모니터링하게 된다. 또한 슬라이딩 자기상관 기법과, 파장-시간 변환 기법을 빠른 센싱과 넓은 범위의 센싱이 가능하도록 하였다. We propose a multiplexed fiber Bragg grating sensor network for vessel monitoring to measure the variation of strain and temperature by...