Low frequency fluctuation instabilities in diode lasers with optical feedback

1994 ◽  
Author(s):  
Elena Cerboneschi ◽  
Ferdinando De Tomasi ◽  
Ennio Arimondo
Keyword(s):  
Optical Feedback ◽  
Diode Lasers ◽  
Low Frequency ◽  
Frequency Fluctuation

High-resolution low-frequency fluctuation map of a multimode laser diode subject to filtered optical feedback via a fiber Bragg grating

2016 ◽  
Vol 41 (13) ◽  
pp. 2950 ◽  
Author(s):  
Fadwa Baladi ◽  
Min Won Lee ◽  
Jean-René Burie ◽  
Mauro A. Bettiati ◽  
Azzedine Boudrioua ◽  
...  
Keyword(s):  
High Resolution ◽  
Fiber Bragg Grating ◽  
Laser Diode ◽  
Optical Feedback ◽  
Low Frequency ◽  
Frequency Fluctuation ◽  
Bragg Grating ◽  
Multimode Laser ◽  
Multimode Laser Diode

Low-frequency fluctuation in multimode semiconductor laser subject to optical feedback

2008 ◽  
Vol 6 (2) ◽  
pp. 120-123 ◽  
Author(s):  
张旭 Xu Zhang ◽  
禹延光 Huiying Ye ◽  
叶会英 Zhaoxin Song
Keyword(s):  
Semiconductor Laser ◽  
Optical Feedback ◽  
Low Frequency ◽  
Frequency Fluctuation

Different cerebral functional segregation in Sjogren’s syndrome with or without systemic lupus erythematosus revealed by amplitude of low-frequency fluctuation

2021 ◽  
pp. 028418512110324
Author(s):  
Xiao-Dong Zhang ◽  
Jun Ke ◽  
Jing-Li Li ◽  
Yun-Yan Su ◽  
Jia-Min Zhou ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Low Frequency ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Frequency Fluctuation ◽  
Parahippocampal Gyrus ◽  
Systemic Lupus ◽  
The Right ◽  
Left Insula

Background Sjögren’s syndrome (SjS) associated with systemic lupus erythematosus (SjS-SLE) was considered a standalone but often-overlooked entity. Purpose To assess altered spontaneous brain activity in SjS-SLE and SjS using amplitude of low-frequency fluctuation (ALFF). Material and Methods Sixteen patients with SjS-SLE, 17 patients with SjS, and 17 matched controls underwent neuropsychological tests and subsequent resting-state functional magnetic resonance imaging (fMRI) examinations. The ALFF value was calculated based on blood oxygen level dependent (BOLD) fMRI. Statistical parametric mapping was utilized to analyze between-group differences and multiple comparison was corrected with Analysis of Functional NeuroImages 3dClustSim. Then, the ALFFs of brain regions with significant differences among the three groups were correlated to corresponding clinical and neuropsychological variables by Pearson correlation. Results ALFF differences in the bilateral precuneus/posterior cingulate cortex (PCC), right parahippocampal gyrus/caudate/insula, and left insula were found among the three groups. Both SjS-SLE and SjS displayed decreased ALFF in the right parahippocampal gyrus, right insula, and left insula than HC. Moreover, SjS-SLE showed wider decreased ALFF in the bilateral precuneus and right caudate, while the SjS group exhibited increased ALFF in the bilateral PCC. Additionally, patients with SjS-SLE exhibited lower ALFF values in the bilateral PCC and precuneus than SjS. Moreover, ALFF values in the right parahippocampal gyrus and PCC were negatively correlated to fatigue score and disease duration, respectively, in SjS-SLE. Conclusion SjS-SLE and SjS exhibited common and different alteration of cerebral functional segregation revealed by AlFF analysis. This result appeared to indicate that SjS-SLE might be different from SjS with a neuroimaging standpoint.

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