Antireflection coatings on LBO crystals: investigation of LIDT scaling with pulse duration at IR and UV wavelengths.

Abstract The use of an antireflection coating for backside semiconductor failure analysis is discussed. The process of selecting an appropriate coating is described. Several known coatings are also described in regards to imaging quality, material properties, and the benefits to device analysis applications.

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Polarisation insensitive, 25 dB gain semiconductor laser amplifier without antireflection coatings

Electronics Letters ◽

10.1049/el:19961220 ◽

1996 ◽

Vol 32 (19) ◽

pp. 1835 ◽

Cited By ~ 26

Author(s):

A.E. Kelly ◽

I.F. Lealman ◽

L.J. Rivers ◽

S.D. Perrin ◽

M. Silver

Keyword(s):

Semiconductor Laser ◽

Antireflection Coatings ◽

Laser Amplifier ◽

Semiconductor Laser Amplifier

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P6595The optogenetic defibrillation of ventricular arrhythmia in myocardial infarction rats in vivo

European Heart Journal ◽

10.1093/eurheartj/ehz746.1183 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

X I Wang ◽

Y Cheng ◽

P Rao ◽

L Wang

Keyword(s):

Light Intensity ◽

Ventricular Arrhythmia ◽

Sinus Rhythm ◽

Pulse Duration ◽

Underlying Mechanism ◽

Blue Laser ◽

Continuous Illumination ◽

Threshold Intensity ◽

Systemic Delivery ◽

Significant Difference

Abstract Introduction Optogenetics is a low-invasive, flexible and highly selective intervention that enables electrical excitation with light on myocardium overexpressing light-sensitive proteins. Optical illumination can control the simultaneous exciting of the whole myocardium under the spot, which is more conducive to recovery from electrical disturbance to sinus rhythm. Purpose We explored optogenetic defibrillation for different illumination parameters how to affect defibrillation rates and the possible mechanism of continuous illumination defibrillation. Methods Systemic delivery via right jugular vein injection of (AAV9-CAG-hChR2(H134R)-mCherry) were performed in juvenile SD rats to achieve the light sensitive protein Channelrhodopsin-2 (ChR2) transfer throughout the whole heart. We intubated and ventilated rats, opened chest and recorded the ECG. After ligation of the left anterior descending coronary artery, ventricular arrhythmia was induced by electrical burst stimulation (10v, 50Hz, 2s). Cardiac epicardium illumination with 470nm blue laser was performed to investigate the effects of optogenetic defibrillation and its underlying mechanism. Every heart accepted 30 pulses of 20ms duration on 8Hz to test the light intensity threshold for 1:1 capture. Different illumination modes of multiple light intensity (2,4,8,10,20 times threshold intensity), pulse duration (20, 50, 200, 500 and 1000ms) and illumination position (RV apex, RV, RVOT, septum, LV) were applied in each attempt for 4 repetitions with 1 s interval. Results We demonstrated that ventricular arrhythmias could be terminated by illumination of the right ventricle at 20 times threshold intensity in 1s (figure A) with the successful defibrillation rate of 95±2.673% (mean ±SEM; N=7). Herein, the successful optogenetic defibrillation rate was strongly depending on light intensity (N=5, n=50 episodes, p=0.0118) and duration of illumination (N=5, n=50 episodes, p<0.0001) (figure B.C). Notably when there were higher intensity and longer pulse duration, the higher defibrillation rate appeared. There was no significant difference in the defibrillation rate among different illumination positions (N=5, n=25episodes per position, p=0.1177) (figure D). To explore the underlying mechanism of optogenetic defibrillation, we performed the same illumination mode during sinus rhythm in 2 rats (figure E. F. G). We observed that higher light intensity and longer pulse duration were more conducive to induce an episode of higher frequency focal excitement. Views of optogenetic defibrillation Conclusions We demonstrated that optogenetic defibrillation is a highly effective intervention and the possible mechanism is partly attributed to overdrive suppression. We believe that optogenetic approach is potentially to be translated into more efficient and pain-free clinical termination of ventricular arrhythmia. Acknowledgement/Funding The national natural science foundation of China (81772044)

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