scholarly journals Review of Low-Cost Photoacoustic Sensing and Imaging Based on Laser Diode and Light-Emitting Diode

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2264 ◽  
Author(s):  
Hongtao Zhong ◽  
Tingyang Duan ◽  
Hengrong Lan ◽  
Meng Zhou ◽  
Fei Gao
Keyword(s):  
Laser Diode ◽  
Imaging System ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Coded Modulation ◽  
Imaging Systems ◽  
Laser Source ◽  
Imaging Method ◽  
Light Emitting ◽  
Laser Sources

Photoacoustic tomography (PAT), a promising medical imaging method that combines optical and ultrasound techniques, has been developing for decades mostly in preclinical application. A recent trend is to utilize the economical laser source to develop a low-cost sensing and imaging system, which aims at an affordable solution in clinical application. These low-cost laser sources have different modulation modes such as pulsed modulation, continuous modulation and coded modulation to generate different profiles of PA signals in photoacoustic (PA) imaging. In this paper, we review the recent development of the photoacoustic sensing and imaging based on the economical laser sources such as laser diode (LD) and light-emitting diode (LED) in different kinds of modulation types, and discuss several representative methods to improve the performance of such imaging systems based on low-cost laser sources. Finally, some perspectives regarding the future development of portable PAT systems are discussed, followed by the conclusion.

scholarly journals Low-cost photoacoustic imaging systems based on laser diode and light-emitting diode excitation

2017 ◽  
Vol 10 (04) ◽  
pp. 1730003 ◽  
Author(s):  
Qingkai Yao ◽  
Yu Ding ◽  
Guodong Liu ◽  
Lvming Zeng
Keyword(s):  
Laser Diode ◽  
Near Infrared ◽  
Photoacoustic Imaging ◽  
Light Emitting Diode ◽  
Imaging Modality ◽  
Low Cost ◽  
Laser System ◽  
Great Promise ◽  
Light Emitting ◽  
Wide Range

Photoacoustic imaging, an emerging biomedical imaging modality, holds great promise for preclinical and clinical researches. It combines the high optical contrast and high ultrasound resolution by converting laser excitation into ultrasonic emission. In order to generate photoacoustic signal efficiently, bulky Q-switched solid-state laser systems are most commonly used as excitation sources and hence limit its commercialization. As an alternative, the miniaturized semiconductor laser system has the advantages of being inexpensive, compact, and robust, which makes a significant effect on production-forming design. It is also desirable to obtain a wavelength in a wide range from visible to near-infrared spectrum for multispectral applications. Focussing on practical aspect, this paper reviews the state-of-the-art developments of low-cost photoacoustic system with laser diode and light-emitting diode excitation source and highlights a few representative installations in the past decade.

Porphyrin doping of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex for electroluminescence

2013 ◽  
Vol 17 (05) ◽  
pp. 351-358 ◽  
Author(s):  
Mohammad Janghouri ◽  
Ezeddin Mohajerani ◽  
Mostafa M. Amini ◽  
Naser Safari
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Energy Levels ◽  
Orbital Energy ◽  
Homogeneous Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Fundamental Structure ◽  
Organic Light

A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex ( Q2SnCl2 , Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/ Q2SnCl2/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q2SnCl2 is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP): Q2SnCl2 (75nm)/ Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.

Low Cost Cooling Device for High Power LED Lamps

2020 ◽  
Author(s):  
Pamela Martinez-Vega ◽  
Araceli Lopez-Badillo ◽  
J. Luis Luviano-Ortiz ◽  
Abel Hernandez-Guerrero ◽  
Jaime G. Cervantes
Keyword(s):  
Reference Model ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Cost Effective ◽  
Heat Sinks ◽  
Modern World ◽  
Type Model ◽  
Light Emitting

Abstract The modern world progressively demands more energy; according to forecasts energy consumption will grow at an average annual rate of 3 percent. Therefore, it is necessary to purchase products or devices that are efficient and environmentally friendly. Technology in LED (Light Emitting Diode) lighting is presented as an alternative to energy saving, since LEDs have proven to be extremely efficient, have a long service life and their cost-effective ratio is very good. However, the heat emitted by the LED chip must be dissipated effectively, since the overheating of the chip reduces the efficiency and lifetime of the lamp. Therefore, heat sinks that are reliable, efficient and inexpensive should be designed and built. The present work proposes new designs for heat sinks in LED lamps, some of the models in the design of the fins refer to the Fibonacci series. The models proposed in the present work that have a significant advantage are the Type 1E Model (5.2% mass savings and better thermal efficiency of 8.33%), GR Type 1 Model (3.12% lighter and 3.33% more efficient) and the GRL Type Model (4. 51% mass savings and 5.55% thermally more efficient) compared to the Type 2 Reference Model proposed by Jang et al. [12].

scholarly journals Preparation of Organic Light-Emitting Diode Using Coal Tar Pitch, a Low-Cost Material, for Printable Devices

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62903 ◽  
Author(s):  
Miki Yamaoka ◽  
Shun-suke Asami ◽  
Nayuta Funaki ◽  
Sho Kimura ◽  
Liao Yingjie ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Low Cost ◽  
Coal Tar ◽  
Coal Tar Pitch ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light

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

2008 ◽  
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.

scholarly journals Development of a Compact Three-Degree-of-Freedom Laser Measurement System with Self-Wavelength Correction for Displacement Feedback of a Nanopositioning Stage

2018 ◽  
Vol 8 (11) ◽  
pp. 2209 ◽  
Author(s):  
Yindi Cai ◽  
Zhifeng Lou ◽  
Siying Ling ◽  
Bo-syun Liao ◽  
Kuang-chao Fan
Keyword(s):  
Laser Diode ◽  
Low Cost ◽  
Michelson Interferometer ◽  
Optical Path Difference ◽  
Path Difference ◽  
Degree Of Freedom ◽  
Laser Source ◽  
Laser Measurement ◽  
Length Unit ◽  
Three Degree Of Freedom

This paper presents a miniature three-degree-of-freedom laser measurement (3DOFLM) system for displacement feedback and error compensation of a nanopositioning stage. The 3DOFLM system is composed of a miniature Michelson interferometer (MMI) kit, a wavelength corrector kit, and a miniature autocollimator kit. A low-cost laser diode is employed as the laser source. The motion of the stage can cause an optical path difference in the MMI kit so as to produce interference fringes. The interference signals with a phase interval of 90° due to the phase control are detected by four photodetectors. The wavelength corrector kit, based on the grating diffraction principle and the autocollimation principle, provides real-time correction of the laser diode wavelength, which is the length unit of the MMI kit. The miniature autocollimator kit based on the autocollimation principle is employed to measure angular errors and compensate induced Abbe error of the moving table. The developed 3DOFLM system was constructed with dimensions of 80 mm (x) × 90 mm (y) × 20 mm (z) so that it could be embedded into the nanopositioning stage. A series of calibration and comparison experiments were carried out to test the performance of this system.

scholarly journals Real-Time Correction and Stabilization of Laser Diode Wavelength in Miniature Homodyne Interferometer for Long-Stroke Micro/Nano Positioning Stage Metrology

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4587 ◽  
Author(s):  
Yindi Cai ◽  
Baokai Feng ◽  
Qi Sang ◽  
Kuang-Chao Fan
Keyword(s):  
Real Time ◽  
Laser Diode ◽  
Low Cost ◽  
Displacement Measurement ◽  
Laser Source ◽  
Wavelength Stabilization ◽  
Positioning Stage ◽  
Drift Compensation ◽  
Optical Configuration ◽  
Long Stroke

A low-cost miniature homodyne interferometer (MHI) with self-wavelength correction and self-wavelength stabilization is proposed for long-stroke micro/nano positioning stage metrology. In this interferometer, the displacement measurement is based on the analysis of homodyne interferometer fringe pattern. In order to miniaturize the interferometer size, a low-cost and small-sized laser diode is adopted as the laser source. The accuracy of the laser diode wavelength is real-time corrected by the proposed wavelength corrector using a modified wavelength calculation equation. The variation of the laser diode wavelength is suppressed by a real-time wavelength stabilizer, which is based on the principle of laser beam drift compensation and the principle of automatic temperature control. The optical configuration of the proposed MHI is proposed. The methods of displacement measurement, wavelength correction, and wavelength stabilization are depicted in detail. A laboratory-built prototype of the MHI is constructed, and experiments are carried out to demonstrate the feasibility of the proposed wavelength correction and stabilization methods.

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