Investigation on optical integration between LED Mid-IR light sources and Si-based waveguides for sensing applications

Abstract Research on mid-IR silicon-based waveguides has recently received strong interest. Particularly, this paper focuses on one of the critical issues in micron-scale photonic integrated circuits, which is to efficiently couple a mid-IR LED (light emitting diode) light source to an external micron-scale waveguide. The optical coupling scheme is crucial for the exploitation of LED light sources in waveguide-based spectroscopic sensing applications. This paper reports optical coupling scheme between an LED mid-IR light source and a silicon rich silicon nitride (SiN) waveguide that could enable the use of LED-based light sources. Finally, the detection limit of the investigated device for carbon dioxide gas detection is calculated.

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Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

Applied Sciences ◽

10.3390/app11094035 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4035

Author(s):

Jinsheon Kim ◽

Jeungmo Kang ◽

Woojin Jang

Keyword(s):

Light Source ◽

High Power ◽

Heat Dissipation ◽

Light Emitting Diode ◽

Light Distribution ◽

Light Sources ◽

Led Light ◽

High Power Led ◽

Distribution Requirement ◽

Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

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Photobiocatalytic alcohol oxidation using LED light sources

Green Chemistry ◽

10.1039/c6gc02008a ◽

2017 ◽

Vol 19 (2) ◽

pp. 376-379 ◽

Cited By ~ 25

Author(s):

M. Rauch ◽

S. Schmidt ◽

I. W. C. E. Arends ◽

K. Oppelt ◽

S. Kara ◽

...

Keyword(s):

Light Source ◽

Photocatalytic Oxidation ◽

Alcohol Oxidation ◽

Light Sources ◽

Blue Led ◽

Led Light

The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported.

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Phantom array and stroboscopic effects of a time-modulated moving light source during saccadic eye movement

Lighting Research and Technology ◽

10.1177/1477153517693468 ◽

2017 ◽

Vol 50 (5) ◽

pp. 772-786 ◽

Cited By ~ 2

Author(s):

C-S Lee ◽

J-H Lee ◽

H Pak ◽

SW Park ◽

D-W Song

Keyword(s):

Eye Movements ◽

Eye Movement ◽

Light Source ◽

Light Emitting Diode ◽

Saccadic Eye Movements ◽

Movement Speed ◽

Light Sources ◽

Saccadic Eye Movement ◽

Modulated Light ◽

Source Motion

This paper evaluates the detectability of the phantom array and stroboscopic effects during light source motion, eye movement and their combination, using time modulated light-emitting diode light sources. It is well known that the phantom array can be observed when time-modulated light sources are observed during saccadic eye movements. We investigated whether light source motion can cause similar effects when the subject has fixed eyes. In addition, we estimated the detectability threshold frequency for the combination of stroboscopic effect and the phantom array, which is named the stroboscopic-phantom array effect, during two eye movements in opposite directions under one directional rotating light source with variable speed. Our results indicate that one of the most important factors for the stroboscopic-phantom array effect is eye movement speed relative to the speed of the light source. Therefore, time-modulated moving light sources induce a stroboscopic effect in subjects with fixed eyes that is similar to the stroboscopic-phantom array effect observed during saccadic eye movement. Our findings are likely to be useful for predicting the stroboscopic effect and the stroboscopic-phantom array effect during the fast motion of time-modulated LED light sources, like multi-functional rear lamps, in automotive lighting applications.

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1.331μm Narrow-Bandwidth Light Source Based on Polymer Micro-Blazed Grating

2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems ◽

10.1115/micronano2008-70207 ◽

2008 ◽

Cited By ~ 1

Author(s):

Hairong Wang ◽

Xianni Gao ◽

Guoliang Sun ◽

Yulong Zhao ◽

Zhuangde Jiang

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Low Cost ◽

Diffraction Order ◽

Blazed Grating ◽

Light Emitting ◽

Led Light ◽

Narrow Bandwidth ◽

Narrow Width ◽

The Cost

In order to detect methane (CH4) accurately and reliably, this paper presents a sensor which consists of infrared diode, fixtures, blazed grating, to realize the extremely narrow-bandwidth light at wavelength of 1.331μm. Based on factors such as compatibility with the transmission characteristics of silica fiber and the cost, a LED (light-emitting diode) with center wavelength of 1.3μm is selected. The LED light is modulated as the parallel light beam. As the light is incident in a micro-blazed grating with certain angle, by diffraction and interference, the light will output the maximum light intensity of its diffraction order at 1.331 μm, which just is an absorption peak of CH4. Micro-blazed grating applied here is low cost and easy replication by various ways, which makes extreme narrow width wavelength possible. Simulation and analysis indicate the designed prototype can output 1.331μm with bandwidth from 1.32907μm to 1.332495μm. With the light source basing on light dividing system, more reliable and higher sensitive measurement of the dangerous gases such as methane and carbon monoxide (CO) can be realized.

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Growth of Ulva pertusa Kjellman (Chlorophyta, Ulvophyceae) by a Light-Emitting Diode (LED) Light Source

Korean Journal of Fisheries and Aquatic Sciences ◽

10.5657/kfas.2013.0571 ◽

2013 ◽

Vol 46 (5) ◽

pp. 571-574

Author(s):

Chun Jung Kwon ◽

Chang Geun Choi

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Ulva Pertusa ◽

Light Emitting ◽

Led Light

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Visibility of the phantom array effect according to luminance, chromaticity and geometry

Lighting Research and Technology ◽

10.1177/1477153519867115 ◽

2019 ◽

Vol 52 (3) ◽

pp. 377-388

Author(s):

SW Park ◽

C-S Lee ◽

HR Kang ◽

HS Pak ◽

A Wilkins

Keyword(s):

Light Source ◽

Pulse Width Modulation ◽

Light Emitting Diode ◽

Field Of View ◽

Light Sources ◽

Experimental Conditions ◽

Threshold Frequency ◽

Automotive Lighting ◽

Lighting Systems ◽

Angular Field Of View

Light-emitting diode-based lighting systems are now applied in both general lighting and automotive lighting. Time-modulated control methods such as pulse width modulation are frequently applied as a dimming method. This paper presents the characteristics of the visibility of the phantom array effect according to luminance, chromaticity and angular field of view. The threshold frequency of the visibility of the phantom array increases in proportion to the logarithm of the luminance of the light source. As the angular field of view of the light source increases, the threshold frequency of the visibility of the array decreases exponentially over a range from 0.125° to 4° in our experimental conditions. The threshold frequency at which the array is visible depends on chromaticity at high light source modulation frequencies. When designing time-modulated light sources, our findings can be applied so as to minimize the phantom array effect.

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Prolonged intra-operative thermal exposure in endoscopic ear surgery: is it really safe?

The Journal of Laryngology & Otology ◽

10.1017/s0022215120001449 ◽

2020 ◽

Vol 134 (8) ◽

pp. 727-731

Author(s):

A Das ◽

S Mitra ◽

P Agarwal ◽

A Sengupta

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Operating Time ◽

Light Sources ◽

Endoscopic Ear Surgery ◽

Ear Surgery ◽

Light Emitting ◽

Operative Complications ◽

Xenon Light Source ◽

Xenon Light

AbstractObjectiveThe aim of this study was to assess change in temperature, audiometric outcomes and post-operative complications following exposure to different light sources during endoscopic ear surgery.MethodA total of 64 patients diagnosed with chronic otitis media with central perforation and pure conductive hearing loss underwent endoscopic type 1 tympanoplasty. The patients were randomised into two groups based on the light source used: xenon or light-emitting diode. Temperature was measured using a K type thermocouple at the promontory and round window niche. Mean temperature change with respect to operating time, mean audiometric change, incidence of vomiting in the first 24 hours, vertigo and tinnitus at the end of the first week were observed.ResultsMean temperature change showed a statistically significant difference with increasing length of operating time with the xenon light source and when the two light sources were compared for a particular time interval. Mean audiometric change showed statistically significant deterioration at higher frequencies (4, 6 and 8 kHz) with the xenon light source but only at 8 kHz for the light emitting diode source. When the mean audiometric change was compared between light sources for a particular frequency, statistical significance was found at 4, 6 and 8 kHz. Post-operative complications were vomiting, vertigo and tinnitus (p-values of 0.042, 0.099 and 0.147, respectively, between two groups).ConclusionLight emitting diodes are associated with less significant middle-ear temperature rises and audiometric changes at higher frequencies when compared to xenon light sources. Hence, xenon should be replaced with cooler light sources.

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Effects of Different LED Light Recipes and NPK Fertilizers on Basil Cultivation for Automated and Integrated Horticulture Methods

Applied Sciences ◽

10.3390/app11062497 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2497

Author(s):

Silvia Barbi ◽

Francesco Barbieri ◽

Alessandro Bertacchini ◽

Luisa Barbieri ◽

Monia Montorsi

Keyword(s):

Controlled Release ◽

Growth Parameters ◽

Light Emitting Diode ◽

Substantial Improvement ◽

Fresh Mass ◽

Light Sources ◽

Npk Fertilizers ◽

Led Light ◽

Deep Blue ◽

Led Lights

This study aims to optimize the conditions for “Genovese” basil (Ocimum Basilicum) germination and growth in an indoor environment suitable for horticulture through a synergic effect of light and fertilizers addition. In fact, several studies determined that specific light conditions are capable of enhancing basil growth, but this effect is highly dependent on the environmental conditions. In this study, the effect of different light sources was determined employing a soil with a negligible amount of fertilizer, demonstrating substantial improvement when light-emitting diode (LED) lights (hyper red and deep blue in different combinations) were applied with respect to daylight (Plants height: +30%, Total fresh mass: +50%). Thereafter, a design of experiment approach has been implemented to calculate the specific combination of LED lights and fertilizer useful to optimize the basil growth. A controlled-release fertilizer based on nitrogen, phosphorus, and potassium (NPK) derived from agro-residues was compared with a soil enriched in macronutrients. The results demonstrate significant improvements for the growth parameters with the employment of the controlled-release NPK with respect to enriched soil combined with a ratio of hyper red and deep blue LED light equal to 1:3 (Total fresh mass: +100%, Leaves number: +20%).

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A Practical Method to Design Reflector-Based Light-Emitting Diode Luminaire for General Lighting

Advances in OptoElectronics ◽

10.1155/2018/7138592 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10

Author(s):

Jinren Yan

Keyword(s):

Light Emitting Diode ◽

Spherical Surface ◽

Target Surface ◽

Practical Method ◽

Optical Simulation ◽

Light Sources ◽

Aspheric Surface ◽

Light Emitting ◽

Led Light ◽

Spherical Reflector

A reflector-based light-emitting diode (LED) luminaire structure that can achieve a large cut-off angle for general lighting is presented in this work. The proposed lighting unit mainly consists of a spherical reflector and a primary packaging lens that contains an aspheric surface and a spherical surface. The light rays emitted from the LED light source are well controlled by the spherical reflector and the aspheric surface of the lens for the purpose of obtaining a uniform illumination on the target surface. Both the ideal Lambertian LED and non-Lambertian LED light sources were employed to validate the proposed structure and the performance of the designed lighting units was analyzed by optical simulation. The results show that the light utilization efficiencies and the estimated uniformities are 92.96% and 91.11% for ideal Lambertian LED-based lighting unit and 93.31% and 91.64% for non-Lambertian LED-based lighting unit, respectively. Further analysis shows that the tolerances of horizontal, vertical, and rotational deviation of the both lighting units were about 2.0 mm, 1.0 mm, and 1.0°, respectively.

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