Evaluation of distributed Bragg reflector lasers for high-sensitivity near-infrared gas analysis

1997 ◽  
Vol 36 (1) ◽  
pp. 117 ◽  
Author(s):  
Anders P. Larson
Keyword(s):  
Near Infrared ◽  
High Sensitivity ◽  
Gas Analysis ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector

scholarly journals Theoretical Investigation of Near-Infrared Fabry–Pérot Microcavity Graphene/Silicon Schottky Photodetectors Based on Double Silicon on Insulator Substrates

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 708
Author(s):  
Maurizio Casalino
Keyword(s):  
Near Infrared ◽  
Incident Light ◽  
Resonant Cavity ◽  
Bragg Reflector ◽  
Silicon On Insulator ◽  
Noise Equivalent Power ◽  
Distributed Bragg Reflector ◽  
Absorption Mechanism ◽  
Output Mirror ◽  
Fabry Perot

In this work a new concept of silicon resonant cavity enhanced photodetector working at 1550 nm has been theoretically investigated. The absorption mechanism is based on the internal photoemission effect through a graphene/silicon Schottky junction incorporated into a silicon-based Fabry–Pérot optical microcavity whose input mirror is constituted by a double silicon-on-insulator substrate. As output mirror we have investigated two options: a distributed Bragg reflector constituted by some periods of silicon nitride/hydrogenated amorphous silicon and a metallic gold reflector. In addition, we have investigated and compared two configurations: one where the current is collected in the transverse direction with respect to the direction of the incident light, the other where it is collected in the longitudinal direction. We show that while the former configuration is characterized by a better responsivity, spectral selectivity and noise equivalent power, the latter configuration is superior in terms of bandwidth and responsivity × bandwidth product. Our results show responsivity of 0.24 A/W, bandwidth in GHz regime, noise equivalent power of 0.6 nW/cm√Hz and full with at half maximum of 8.5 nm. The whole structure has been designed to be compatible with silicon technology.

scholarly journals Designing multilayer dielectric filter based on TiO2/SiO2 for fluorescence microscopy applications

2020 ◽  
Vol 44 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Hanh Hong Mai
Keyword(s):  
Fluorescence Microscopy ◽  
Near Infrared ◽  
Narrow Band ◽  
Synthesis Method ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
Construction Design ◽  
Needle Technique ◽  
Spectral Performance ◽  
New Construction

This study presents a new construction design of a distributed Bragg reflector (DBR) filter and a Fabry–Pérot (FP) filter by using needle technique as a synthesis method. The optimized DBR and FP filters having a proper number of layers with controlling thickness TiO2/SiO2 are utilized to transmit only a certain narrow band of wavelengths while blocking the others. As a proof of concept, the filters are designed to selectively transmit only a very narrow band of wavelength at 780 nm which is the near infrared (NIR) fluorescent emission from Alexa Fluor 750 dye. The obtained results show that the optimized filters represent advanced spectral performance which can be used to improve the sensitivity and the imaging contrast in fluorescence microscopy.

High Sensitivity Micro-Vibration Sensor Based on Distributed Bragg Reflector Fiber Laser

2014 ◽  
Vol 34 (7) ◽  
pp. 0728006 ◽  
Author(s):  
鲁文高 Lu Wengao ◽  
孙琪真 Sun Qizhen ◽  
沃江海 Wo Jianghai ◽  
王贺 Wang He ◽  
刘德明 Liu Deming
Keyword(s):  
Fiber Laser ◽  
High Sensitivity ◽  
Bragg Reflector ◽  
Vibration Sensor ◽  
Distributed Bragg Reflector ◽  
Micro Vibration

Demonstration of a widely tunable digital supermode distributed Bragg reflector laser as a versatile source for near-infrared spectroscopy

2012 ◽  
Vol 110 (2) ◽  
pp. 139-145 ◽  
Author(s):  
L. Ciaffoni ◽  
G. Hancock ◽  
P. L. Hurst ◽  
M. Kingston ◽  
C. E. Langley ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector

Efficacy of Near-Infrared Spectrometry for Monitoring the Cerebral Effects of Severe Dilutional Anemia

2014 ◽  
Vol 17 (3) ◽  
pp. 154 ◽  
Author(s):  
Arıtürk Cem ◽  
Ustalar Serpil ◽  
Toraman Fevzi ◽  
Ökten Murat ◽  
Güllü Ümit ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Surgery ◽  
Blood Lactate ◽  
Near Infrared ◽  
Bypass Graft ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Infrared Spectrometry ◽  
Control Group ◽  
Near Infrared Spectrometry

<p><strong>Introduction:</strong> Clear guidelines for red cell transfusion during cardiac surgery have not yet been established. The current focus on blood conservation during cardiac surgery has increased the urgency to determine the minimum safe hematocrit for these patients. The aim of this study was to determine whether monitoring of cerebral regional oxygen saturation (rSO<sub>2</sub>) via near-infrared spectrometry (NIRS) is effective for assessing the cerebral effects of severe dilutional anemia during elective coronary arterial bypass graft surgery (CABG).</p><p><strong>Methods:</strong> The prospective observational study involved patients who underwent cerebral rSO<sub>2</sub> monitoring by NIRS during elective isolated first-time CABG: an anemic group (<em>N</em>=15) (minimum Hemoglobin (Hb) N=15) (Hb &gt;8 g/dL during CPB). Mean arterial pressure (MAP), pump blood flow, blood lactate level, pCO<sub>2</sub>, pO<sub>2</sub> at five time points and cross-clamp time, extracorporeal circulation time were recorded for each patient. Group results statistically were compared.</p><p><strong>Results:</strong> The anemic group had significantly lower mean preoperative Hb than the control group (10.3 mg/dL versus 14.2 mg/dL; <em>P</em> = .001). The lowest Hb levels were observed in the hypothermic period of CPB in the anemic group. None of the controls exhibited a &gt;20% decrease in cerebral rSO<sub>2</sub>. Eleven (73.3%) of the anemic patients required an increase in pump blood flow to raise their cerebral rSO<sub>2</sub>.</p><p><strong>Conclusions:</strong> In this study, the changes in cerebral rSO<sub>2</sub> in the patients with low Hb were within acceptable limits, and this was in concordance with the blood lactate levels and blood-gas analysis. It can be suggested that NIRS monitoring of cerebral rSO<sub>2</sub> can assist in decision making related to blood transfusion and dilutional anemia during CPB.</p>

scholarly journals Metal Oxide Nanorods-Based Sensor Array for Selective Detection of Biomarker Gases

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1922
Author(s):  
Gwang Su Kim ◽  
Yumin Park ◽  
Joonchul Shin ◽  
Young Geun Song ◽  
Chong-Yun Kang
Keyword(s):  
Real Time ◽  
Sensor Array ◽  
High Sensitivity ◽  
Gas Analysis ◽  
Diagnostic Methods ◽  
Real Time Monitoring ◽  
Non Invasive ◽  
Sensitivity And Selectivity ◽  
Breath Gas Analysis ◽  
Angle Method

The breath gas analysis through gas phase chemical analysis draws attention in terms of non-invasive and real time monitoring. The array-type sensors are one of the diagnostic methods with high sensitivity and selectivity towards the target gases. Herein, we presented a 2 × 4 sensor array with a micro-heater and ceramic chip. The device is designed in a small size for portability, including the internal eight-channel sensor array. In2O3 NRs and WO3 NRs manufactured through the E-beam evaporator’s glancing angle method were used as sensing materials. Pt, Pd, and Au metal catalysts were decorated for each channel to enhance functionality. The sensor array was measured for the exhaled gas biomarkers CH3COCH3, NO2, and H2S to confirm the respiratory diagnostic performance. Through this operation, the theoretical detection limit was calculated as 1.48 ppb for CH3COCH3, 1.9 ppt for NO2, and 2.47 ppb for H2S. This excellent detection performance indicates that our sensor array detected the CH3COCH3, NO2, and H2S as biomarkers, applying to the breath gas analysis. Our results showed the high potential of the gas sensor array as a non-invasive diagnostic tool that enables real-time monitoring.

scholarly journals Author Correction: High-sensitivity imaging of time-domain near-infrared light transducer

2021 ◽  
Author(s):  
Yuyang Gu ◽  
Zhiyong Guo ◽  
Wei Yuan ◽  
Mengya Kong ◽  
Yulai Liu ◽  
...  
Keyword(s):  
Time Domain ◽  
Near Infrared ◽  
High Sensitivity ◽  
Infrared Light ◽  
Near Infrared Light
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