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Ben-David K, Wittels HL, Wishon MJ, Lee SJ, McDonald SM, Howard Wittels S. Tracking Cancer: Exploring Heart Rate Variability Patterns by Cancer Location and Progression. Cancers (Basel) 2024; 16:962. [PMID: 38473322 DOI: 10.3390/cancers16050962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/18/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Reduced heart rate variability (HRV) is an autonomic nervous system (ANS) response that may indicate dysfunction in the human body. Consistent evidence shows cancer patients elicit lower HRV; however, only select cancer locations were previously evaluated. Thus, the aim of the current study was to explore HRV patterns in patients diagnosed with and in varying stages of the most prevalent cancers. At a single tertiary academic medical center, 798 patients were recruited. HRV was measured via an armband monitor (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA) equipped with electrocardiographic capabilities and was recorded for 5 to 7 min with patients seated in an upright position. Three time-domain metrics were calculated: SDNN (standard deviation of the NN interval), rMSSD (the root mean square of successive differences of NN intervals), and the percentage of time in which the change in successive NN intervals exceeds 50ms within a measurement (pNN50). Of the 798 patients, 399 were diagnosed with cancer. Cancer diagnoses were obtained via medical records one week following the measurement. Analysis of variance models were performed comparing the HRV patterns between different cancers, cancer stages (I-IV), and demographic strata. A total of 85% of the cancer patients had breast, gastrointestinal, genitourinary, or respiratory cancer. The cancer patients were compared to a control non-cancer patient population with similar patient size and distributions for sex, age, body mass index, and co-morbidities. For all HRV metrics, non-cancer patients exhibited significantly higher rMSSDs (11.1 to 13.9 ms, p < 0.0001), SDNNs (22.8 to 27.7 ms, p < 0.0001), and pNN50s (6.2 to 8.1%, p < 0.0001) compared to stage I or II cancer patients. This significant trend was consistently observed across each cancer location. Similarly, compared to patients with stage III or IV cancer, non-cancer patients possessed lower HRs (-11.8 to -14.0 bpm, p < 0.0001) and higher rMSSDs (+31.7 to +32.8 ms, p < 0.0001), SDNNs (+45.2 to +45.8 ms), p < 0.0001, and pNN50s (19.2 to 21.6%, p < 0.0001). The HR and HRV patterns observed did not significantly differ between cancer locations (p = 0.96 to 1.00). The depressed HRVs observed uniformly across the most prevalent cancer locations and stages appeared to occur independent of patients' co-morbidities. This finding highlights the potentially effective use of HRV as a non-invasive tool for determining common cancer locations and their respective stages. More studies are needed to delineate the HRV patterns across different ages, between sexes and race/ethnic groups.
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Affiliation(s)
- Kfir Ben-David
- Department of Surgery, Division of Oncology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
- Department of Surgery, Wertheim School of Medicine, Florida International University, Miami, FL 33199, USA
| | - Harrison L Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA
- Science, Technology and Research, Inc., Miami, FL 33156, USA
| | | | - Stephen J Lee
- United States Army Research Laboratory, United States Army Combat Capabilities Development Command, Adelphi, MD 20783, USA
| | - Samantha M McDonald
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA
- School of Kinesiology and Recreation, Illinois State University, Normal, IL 61761, USA
| | - S Howard Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA
- Science, Technology and Research, Inc., Miami, FL 33156, USA
- Department of Anesthesiology, Mount Sinai Medical Center, Miami, FL 33140, USA
- Department of Anesthesiology, Wertheim School of Medicine, Florida International University, Miami, FL 33199, USA
- Miami Beach Anesthesiology Associates, Miami, FL 33140, USA
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Renaghan E, Wittels HL, Feigenbaum LA, Wishon MJ, Chong S, Wittels ED, Hendricks S, Hecocks D, Bellamy K, Girardi J, Lee S, Vo T, McDonald SM, Wittels SH. Exposures to Elevated Core Temperatures during Football Training: The Impact on Autonomic Nervous System Recovery and Function. Sports (Basel) 2023; 12:8. [PMID: 38251282 PMCID: PMC10819443 DOI: 10.3390/sports12010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024] Open
Abstract
Exercising with elevated core temperatures may negatively affect autonomic nervous system (ANS) function. Additionally, longer training duration under higher core temperatures may augment these negative effects. This study evaluated the relationship between exercise training duration and 24 h ANS recovery and function at ≥37 °C, ≥38 °C and ≥39 °C core temperature thresholds in a sample of male Division I (D1) collegiate American football athletes. Fifty athletes were followed over their 25-week season. Using armband monitors (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA), core temperature (°C) and 24 h post-exercise baseline heart rate (HR), HR recovery and heart rate variability (HRV) were measured. For HRV, two time-domain indices were measured: the root mean square of the standard deviation of the NN interval (rMSSD) and the standard deviation of the NN interval (SDNN). Linear regression models were performed to evaluate the associations between exercise training duration and ANS recovery (baseline HR and HRV) and function (HR recovery) at ≥37 °C, ≥38 °C and ≥39 °C core temperature thresholds. On average, the athletes were 21.3 (± 1.4) years old, weighed 103.0 (±20.2) kg and had a body fat percentage of 15.4% (±7.8%, 3.0% to 36.0%). The duration of training sessions was, on average, 161.1 (±40.6) min and they ranged from 90.1 to 339.6 min. Statistically significant associations between training duration and 24 h ANS recovery and function were observed at both the ≥38.0 °C (baseline HR: β = 0.10 ± 0.02, R2 = 0.26, p < 0.0000; HR recovery: β = -0.06 ± 0.02, R2 = 0.21, p = 0.0002; rMSSD: β = -0.11 ± 0.02, R2 = 0.24, p < 0.0000; and SDNN: β = -0.16 ± 0.04, R2 = 0.22, p < 0.0000) and ≥39.0 °C thresholds (β = 0.39 ± 0.05, R2 = 0.62, p < 0.0000; HR recovery: β = -0.26 ± 0.04, R2 = 0.52, p < 0.0000; rMSSD: β = -0.37 ± 0.05, R2 = 0.58, p < 0.0000; and SDNN: β = -0.67 ± 0.09, R2 = 0.59, p < 0.0000). With increasing core temperatures, increases in slope steepness and strengths of the associations were observed, indicating accelerated ANS deterioration. These findings demonstrate that exercise training under elevated core temperatures (≥38 °C) may negatively influence ANS recovery and function 24 h post exercise and progressively worsen.
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Affiliation(s)
- Eric Renaghan
- Department of Athletics, Sports Science, University of Miami, Miami, FL 33146, USA; (E.R.); (L.A.F.)
| | - Harrison L. Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Luis A. Feigenbaum
- Department of Athletics, Sports Science, University of Miami, Miami, FL 33146, USA; (E.R.); (L.A.F.)
- Department of Physical Therapy, Miller School of Medicine, University of Miami, Miami, FL 33146, USA;
| | - Michael J. Wishon
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Stephanie Chong
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Eva D. Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Stephanie Hendricks
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Dustin Hecocks
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
| | - Kyle Bellamy
- Department of Athletics, Nutrition, University of Miami, Miami, FL 33146, USA;
| | - Joe Girardi
- Department of Physical Therapy, Miller School of Medicine, University of Miami, Miami, FL 33146, USA;
| | - Stephen Lee
- United States Army Research Laboratory, Adelphi, MD 20783, USA;
| | - Tri Vo
- Navy Medical Center—San Diego, San Diego, CA 92134, USA;
| | - Samantha M. McDonald
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
- School of Kinesiology and Recreation, Illinois State University, Normal, IL 61761, USA
| | - S. Howard Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33156, USA; (H.L.W.); (M.J.W.); (S.C.); (E.D.W.); (S.H.); (D.H.); (S.H.W.)
- Department of Anesthesiology, Mount Sinai Medical Center, Miami, FL 33140, USA
- Department of Anesthesiology, Wertheim School of Medicine, Florida International University, Miami, FL 33199, USA
- Miami Beach Anesthesiology Associates, Miami, FL 33140, USA
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Temme LA, Wittels HL, Wishon MJ, St. Onge P, McDonald SM, Hecocks D, Wittels SH. Continuous Physiological Monitoring of the Combined Exposure to Hypoxia and High Cognitive Load in Military Personnel. Biology (Basel) 2023; 12:1398. [PMID: 37997997 PMCID: PMC10669144 DOI: 10.3390/biology12111398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/25/2023]
Abstract
Military aviators endure high cognitive loads and hypoxic environments during flight operations, impacting the autonomic nervous system (ANS). The synergistic effects of these exposures on the ANS, however, are less clear. This study investigated the simultaneous effects of mild hypoxia and high cognitive load on the ANS in military personnel. This study employed a two-factor experimental design. Twenty-four healthy participants aged between 19 and 45 years were exposed to mild hypoxia (14.0% O2), normoxia (21.0% O2), and hyperoxia (33.0% O2). During each epoch (n = 5), participants continuously performed one 15 min and one 10 min series of simulated, in-flight tasks separated by 1 min of rest. Exposure sequences (hypoxia-normoxia and normoxia-hyperoxia) were separated by a 60 min break. Heart rate (HR), heart rate variability (HRV), and O2 saturation (SpO2) were continuously measured via an armband monitor (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA). Paired and independent t-tests were used to evaluate differences in HR, HRV, and SpO2 within and between exposure sequences. Survival analyses were performed to assess the timing and magnitude of the ANS responses. Sympathetic nervous system (SNS) activity during hypoxia was highest in epoch 1 (HR: +6.9 bpm, p = 0.002; rMSSD: -9.7 ms, p = 0.003; SDNN: -11.3 ms, p = 0.003; SpO2: -8.4%, p < 0.0000) and appeared to slightly decline with non-significant increases in HRV. During normoxia, SNS activity was heightened, albeit non-significantly, in epoch 1, with higher HR (68.5 bpm vs. 73.0 bpm, p = 0.06), lower HRV (rMSSD: 45.1 ms vs. 38.7 ms, p = 0.09 and SDNN: 52.5 ms vs. 45.1 ms, p = 0.08), and lower SpO2 (-0.7% p = 0.05). In epochs 2-4, HR, HRV, and SpO2 trended towards baseline values. Significant between-group differences in HR, HRV, and O2 saturation were observed. Hypoxia elicited significantly greater HRs (+5.0, p = 0.03), lower rMSSD (-7.1, p = 0.03), lower SDNN (-8.2, p = 0.03), and lower SpO2 (-1.4%, p = 0.002) compared to normoxia. Hyperoxia appeared to augment the parasympathetic reactivation reflected by significantly lower HR, in addition to higher HRV and O2 relative to normoxia. Hypoxia induced a greater ANS response in military personnel during the simultaneous exposure to high cognitive load. The significant and differential ANS responses to varying O2 levels and high cognitive load observed highlight the importance of continuously monitoring multiple physiological parameters during flight operations.
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Affiliation(s)
- Leonard A. Temme
- Army Aeromedical Research Laboratory, Fort Novosel, AL 36362, USA; (L.A.T.); (P.S.O.)
| | | | - Michael J. Wishon
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
| | - Paul St. Onge
- Army Aeromedical Research Laboratory, Fort Novosel, AL 36362, USA; (L.A.T.); (P.S.O.)
| | - Samantha M. McDonald
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
- School of Kinesiology and Recreation, Illinois State University, Normal, IL 61761, USA
| | - Dustin Hecocks
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
| | - S. Howard Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
- Department of Anesthesiology, Mount Sinai Medical Center, Miami, FL 33140, USA
- Department of Anesthesiology, Wertheim School of Medicine, Florida International University, Miami, FL 33199, USA
- Miami Beach Anesthesiology Associates, Miami, FL 33140, USA
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Peck J, Wishon MJ, Wittels H, Hasty F, Hendricks S, Lee SJ, Wittels SH. COVID-19-Induced Changes in Photoplethysmography. Mil Med 2023; 188:usad025. [PMID: 36852874 DOI: 10.1093/milmed/usad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/13/2022] [Accepted: 02/03/2023] [Indexed: 03/01/2023] Open
Abstract
INTRODUCTION Photoplethysmography (PPG) is the science behind many commonly used medical devices such as the pulse oximeter. PPG changes, herein as "PPG dropouts," have been described in existing in vitro studies following artificially induced clot activation. Because COVID-19 causes increased arterial, venous, and microvascular clot formation, our hypothesis is that PPG dropouts identified in vitro can also be found in vivo in patients with COVID-19. The aim of this study is to evaluate PPG recordings and D-dimer levels for patients hospitalized with COVID-19 and compare them with the PPG tracings from non-COVID controls. MATERIALS AND METHODS PPG recordings were obtained for 197 ICU patients with COVID-19 and 300 non-COVID controls. PPG tracings were obtained using a TigerTech CovidPlus monitor, which received U.S. FDA emergency use authorization in March 2020 for monitoring the biometrics of patients with COVID-19 and featured unfiltered red and infrared spectrum PPG monitoring. D-dimer lab results were also recorded whenever available. RESULTS The results demonstrated significant differences in the prevalence rate of PPG dropout among patients with COVID-19 vs. non-COVID controls. The median PPG dropout rate was 0.58 for COVID-19 patients (median 0.58, IQR 0.42-0.72, P < .05) as opposed to a median 0.0 for non-COVID patients (median 0.0, IQR 0.0-0.0, P < .05). Furthermore, at least one incidence of PPG dropout was detected in 100% of COVID-19 patients, as opposed to 2.3% of non-COVID controls (P < .05). PPG dropout also correlated closely with the normalized serum D-dimer levels taken on the same day. The change in the normalized D-dimer levels was plotted against the change in PPG dropout, and a line of best fit was created. Linear regression resulted in R2 = 0.743 (P < .05), indicating that changes in the PPG dropout rate correlate with hemorheological changes in COVID-19 patients. CONCLUSIONS PPG dropout, like D-dimer, may not be specific for COVID-19. However, the inflammatory nature of the disease and the prevalence of prolonged ICU created a large sample size and allowed the authors to observe PPG changes in vivo in a statistically meaningful way. Further confirmatory studies are needed to confirm the potential application of PPG dropout as a measure of inflammation in other disease processes.
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Affiliation(s)
- Jacquelin Peck
- Department of Anesthesiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | - Frederick Hasty
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
| | - Stephanie Hendricks
- Tiger Tech Solutions, Inc., Miami, FL 33131, USA
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
| | - Stephen J Lee
- Army Research Office, U.S. Army Research Laboratory, DEVCOM-AFC, Adelphi, MD 20783, USA
| | - S Howard Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33131, USA
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL 33140, USA
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Peck J, Wishon MJ, Wittels H, Davila H, Wittels SH, J Lee S. Comment on 'pulse rate variability in cardiovascular health: a review on its applications and relationship with heart rate variability'. Physiol Meas 2021; 42. [PMID: 34617518 DOI: 10.1088/1361-6579/ac1dec] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/16/2021] [Indexed: 11/12/2022]
Affiliation(s)
- Jacquelin Peck
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States of America
| | | | | | - Hector Davila
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States of America.,Tiger Tech Solutions, Inc. Miami, FL, United States of America
| | - S Howard Wittels
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States of America.,Tiger Tech Solutions, Inc. Miami, FL, United States of America
| | - Stephen J Lee
- US Army Research Laboratory, DEVCOM-AFC, United States of America
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Peck J, Wishon MJ, Wittels H, Lee SJ, Hendricks S, Davila H, Wittels SH. Single limb electrocardiogram using vector mapping: Evaluation and validation of a novel medical device. J Electrocardiol 2021; 67:136-141. [PMID: 34242911 DOI: 10.1016/j.jelectrocard.2021.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 11/17/2022]
Abstract
INTRODUCTION The Tiger Tech Warfighter Monitor (WFM) is a novel single-limb device for ECG acquisition. The WFM provides true (not derived) single limb Electrocardiogram monitoring (ECG) to provide heart rate and R-R interval monitoring between QRS complexes. Herein, we evaluate the diagnostic accuracy of the WFM heart rate, R-R interval monitoring, and heart rate variability monitoring in comparison to a 2‑lead chest ECG. METHODS Data was collected under Institutional Review Board (IRB) approval. Patients available within our institution's pre-operative holding unit were randomly selected to undergo simultaneous chest and WFM ECG monitoring. 3-5-min measurements were taken depending on the patient's availability. Data was saved to two separate mobile phones and time-stamped for synchronization. A proprietary Tiger Tech extraction algorithm was used to tag proper features on both the WFM 1-Limb ECG and Chest ECG data files. A separate algorithm was then used to compare the beat-to-beat variations between the ECGs. RESULTS Data was extracted and analyzed on 26 subjects. Linear regression of heart rate analysis revealed excellent correlations with an R2 of 0.99 (p < 0.05). Similar linear regression evaluation of R-R interval correlation demonstrated a mean R2 value of 0.95 (p < 0.05). Statistically significant correlation was achieved in all 26 included study participants. Heart rate variability also achieved excellent correlation (SDNN R2 = 0.997, RMSSD R2 = 0.995, LnRMSSD R2 = 0.992, p << 0.05). CONCLUSION Results demonstrate that the WFM achieves excellent correlation with chest ECG for heart rate, R-R internals, and heart rate variability.
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Affiliation(s)
- Jacquelin Peck
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States.
| | | | | | - Stephen J Lee
- US Army Research Laboratory, DEVCOM-AFC, United States
| | - Stephanie Hendricks
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States; Tiger Tech Solutions, Inc., Miami, FL, United States
| | - Hector Davila
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States; Tiger Tech Solutions, Inc., Miami, FL, United States
| | - S Howard Wittels
- Department of Anesthesiology, Mount Sinai Medical Center, Miami Beach, FL, United States; Tiger Tech Solutions, Inc., Miami, FL, United States
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Choi D, Wishon MJ, Viktorov EA, Citrin DS, Locquet A. Nanometric sensing with laser feedback interferometry. Opt Lett 2019; 44:903-906. [PMID: 30768016 DOI: 10.1364/ol.44.000903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/15/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate a nanometric sensor based on feedback interferometry in a distributed feedback (DFB) laser by using a measurement of either the optical frequency or laser voltage. We find that in an optimal range of optical feedback, the sensor operates reliably down to an extrapolated 12 nm; for the sensor demonstrated here at ∼1550 nm, this provides a minimum detectible displacement of λ/130.
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Choi D, Wishon MJ, Chang CY, Citrin DS, Locquet A. Multistate intermittency on the route to chaos of a semiconductor laser subjected to optical feedback from a long external cavity. Chaos 2018; 28:011102. [PMID: 29390638 DOI: 10.1063/1.5013332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We observe experimentally two regimes of intermittency on the route to chaos of a semiconductor laser subjected to optical feedback from a long external cavity as the feedback level is increased. The first regime encountered corresponds to multistate intermittency involving two or three states composed of several combinations of periodic, quasiperiodic, and subharmonic dynamics. The second regime is observed for larger feedback levels and involves intermittency between period-doubled and chaotic regimes. This latter type of intermittency displays statistical properties similar to those of on-off intermittency.
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Affiliation(s)
- Daeyoung Choi
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, F-57070 Metz, France
| | - Michael J Wishon
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, F-57070 Metz, France
| | - C Y Chang
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, F-57070 Metz, France
| | - D S Citrin
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, F-57070 Metz, France
| | - A Locquet
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, F-57070 Metz, France
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Kelleher B, Wishon MJ, Locquet A, Goulding D, Tykalewicz B, Huyet G, Viktorov EA. Delay induced high order locking effects in semiconductor lasers. Chaos 2017; 27:114325. [PMID: 29195329 DOI: 10.1063/1.4994029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Multiple time scales appear in many nonlinear dynamical systems. Semiconductor lasers, in particular, provide a fertile testing ground for multiple time scale dynamics. For solitary semiconductor lasers, the two fundamental time scales are the cavity repetition rate and the relaxation oscillation frequency which is a characteristic of the field-matter interaction in the cavity. Typically, these two time scales are of very different orders, and mutual resonances do not occur. Optical feedback endows the system with a third time scale: the external cavity repetition rate. This is typically much longer than the device cavity repetition rate and suggests the possibility of resonances with the relaxation oscillations. We show that for lasers with highly damped relaxation oscillations, such resonances can be obtained and lead to spontaneous mode-locking. Two different laser types--a quantum dot based device and a quantum well based device-are analysed experimentally yielding qualitatively identical dynamics. A rate equation model is also employed showing an excellent agreement with the experimental results.
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Affiliation(s)
- B Kelleher
- Department of Physics, University College Cork, Cork, Ireland
| | - M J Wishon
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, 57070 Metz, France
| | - A Locquet
- Georgia Tech-CNRS UMI 2958, Georgia Tech Lorraine, 2 Rue Marconi, 57070 Metz, France
| | - D Goulding
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
| | - B Tykalewicz
- Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
| | - G Huyet
- Université Côte d'Azur, CNRS, Institut de Physique de Nice, Valbonne F-06560, France
| | - E A Viktorov
- National Research University of Information Technologies, Mechanics and Optics, 49 Kronverksky Pr., St Petersburg 197101, Russia
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Choi D, Wishon MJ, Barnoud J, Chang CY, Bouazizi Y, Locquet A, Citrin DS. Low-frequency fluctuations in an external-cavity laser leading to extreme events. Phys Rev E 2016; 93:042216. [PMID: 27176302 DOI: 10.1103/physreve.93.042216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Indexed: 06/05/2023]
Abstract
We experimentally investigate the dynamical regimes of a laser diode subject to external optical feedback in light of extreme-event (EE) analysis. We observe EEs in the low-frequency fluctuations (LFFs) regime. This number decreases to negligible values when the laser transitions towards fully developed coherence collapse as the injection current is increased. Moreover, we show that EEs observed in the LFF regime are linked to high-frequency pulsing events observed after a power dropout. Finally, we prove experimentally that the observation of EEs in the LFF regimes is robust to changes in operational parameters.
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Affiliation(s)
- Daeyoung Choi
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
| | - Michael J Wishon
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
| | - J Barnoud
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
| | - C Y Chang
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA
| | - Y Bouazizi
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
| | - A Locquet
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
| | - D S Citrin
- UMI 2958 Georgia Tech-CNRS, Georgia Tech Lorraine, 2 Rue Marconi F-57070, Metz, France
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
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