Noninvasive, low-noise, fast imaging of blood volume and deoxygenation changes in muscles using light-emitting diode continuous-wave imager

2002 ◽  
Vol 73 (8) ◽  
pp. 3065-3074 ◽  
Author(s):  
Yuanqing Lin ◽  
Gwen Lech ◽  
Shoko Nioka ◽  
Xavier Intes ◽  
Britton Chance
Keyword(s):  
Blood Volume ◽  
Continuous Wave ◽  
Light Emitting Diode ◽  
Low Noise ◽  
Fast Imaging ◽  
Light Emitting

scholarly journals High Stability LED-Pumped Nd:YVO4 Laser with a Cr:YAG for Passive Q-Switching

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 201
Author(s):  
Xiao ◽  
Zhao ◽  
Ge ◽  
Zhong ◽  
Li ◽  
...  
Keyword(s):  
Peak Power ◽  
High Stability ◽  
Continuous Wave ◽  
Light Emitting Diode ◽  
Pump Energy ◽  
Optical Conversion Efficiency ◽  
Sharp Decline ◽  
Light Emitting ◽  
Q Switching ◽  
The Cost

With improvements in light-emitting diode (LED) performance and a sharp decline in price, a light source with the irradiance of a laser and the cost of an LED is worthy of further study. We demonstrated a LED-pumped Nd:YVO4 laser in quasi-continuous-wave (QCW) and passively Q-switched (PQS) regime. With an incident pump energy of 6.28 mJ (150 μs pulses at 1 Hz), the Nd:YVO4 laser has an energy of 206 μJ at 1064 nm in the QCW regime. The optical conversion efficiency of the system is 4.1%, and the slope efficiency is 9.0%. A pulsed energy of 2.5 μJ was obtained with a duration of 897 ns (FWHM) in the PQS regime, which means the peak power is 2.79 W. The output energy stability is 97.54%.

scholarly journals Effect of light-emitting diode phototherapy on pain and trismus following surgical extraction of impacted mandibular third molars

2021 ◽  
Author(s):  
Gholamreza Shirani ◽  
Mohammad Reza Reshadi
Keyword(s):  
Continuous Wave ◽  
Light Emitting Diode ◽  
Control Group ◽  
Third Molars ◽  
Light Emitting ◽  
Led Phototherapy ◽  
Surgical Extraction ◽  
Impacted Mandibular Third Molars ◽  
Mandibular Third Molars ◽  
Effect Of Light

Purpose: This study aimed to assess the effect of light-emitting diode (LED) phototherapy on pain and trismus following surgical extraction of impacted mandibular third molars. Materials and Methods: This double-blind randomized controlled clinical trial evaluated 50 patients between 20 to 35 years requiring extraction of their impacted mandibular third molars. The patients were randomized into two groups of LED phototherapy and control by flipping a coin. Patients in the LED group underwent LED phototherapy immediately after surgery with red light at 618nm wavelength, 20 mW/cm2 power density and 4 J/cm2 energy density in continuous-wave mode (irradiated area: 3.15cm×1.5cm=4.725cm2). The LED device was used in off mode in the control group (as placebo). The level of postoperative pain was measured by the numerical rating scale, and trismus of patients was evaluated by measuring the maximum mouth opening (MMO). The two groups were compared by the Mann-Whitney and NPar tests. Results: The mean difference in MMO postoperatively, compared with baseline, was lower in the LED group than the placebo group but not significantly (P=0.465). The two groups were not significantly different regarding the level of pain. Conclusion: LED phototherapy with the parameters applied in this study failed to significantly decrease the level of pain and trismus following surgical extraction of impacted mandibular third molars.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

Effects of Nitridation Time on Top-emission Inverted Organic Light Emitting Diode

PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 821-824 ◽  
Author(s):  
Chien-Chang Tseng ◽  
Liang-Wen Ji ◽  
Yu Sheng Tsai ◽  
Fuh-Shyang Juang
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Nitridation Time ◽  
Organic Light
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