We demonstrate a simplified approach toward active polarization control in coherently combined laser architectures. By leveraging optical phase dithers applied by a phase controller, polarization error signals are generated for an entire laser array from a single beam sample of the combined output, enabling closed-loop polarization locking of non-polarization-maintaining fibers. The concept is shown to be compatible with both hill-climbing and synchronous multidither phase control methods. Simultaneous phase locking and polarization locking was demonstrated for a five-fiber array with >99% phasing efficiency and >20 dB polarization extinction ratio.
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http://dx.doi.org/10.1364/OL.37.004272 | DOI Listing |
Circ Cardiovasc Interv
January 2025
Department of Cardiology, Radboud University Medical Center, Nijmegen, the Netherlands (R.H.J.A.V., J.-Q.M., N.v.R.).
Background: Despite fractional flow reserve (FFR)-guided deferral of revascularization, recurrent events in patients with diabetes or after myocardial infarction remain common. This study aimed to assess the association between FFR-negative but high-risk nonculprit lesions and clinical outcomes.
Methods: This is a patient-level pooled analysis of the prospective natural-history COMBINE (OCT-FFR) study (Optical Coherence Tomography Morphologic and Fractional Flow Reserve Assessment in Diabetes Mellitus Patients) and PECTUS-obs study (Identification of Risk Factors for Acute Coronary Events by OCT After STEMI and NSTEMI Patients With Residual Non- Flow Limiting Lesions).
Nanophotonics
January 2025
Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Kasprzaka 44/52, Poland.
A combination of femtosecond stimulated Raman scattering and surface-enhanced Raman scattering, termed surface-enhanced stimulated Raman scattering (SE-FSRS), was proposed to leverage both temporal precision and sensitivity for advanced molecular dynamics analysis. During the initial successful implementations of this approach, unexpected spectral distortions were observed, and several potential explanations were proposed. Further progress in this novel technique and its broader implementation requires a profound understanding of the factors influencing the shape of the registered spectra and the underlying mechanisms.
View Article and Find Full Text PDFNanophotonics
January 2025
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Sum-frequency generation (SFG) enables the coherent upconversion of electromagnetic signals and plays a significant role in mid-infrared vibrational spectroscopy for molecular analysis. Recent research indicates that plasmonic nanocavities, which confine light to extremely small volumes, can facilitate the detection of vibrational SFG signals from individual molecules by leveraging surface-enhanced Raman scattering combined with mid-infrared laser excitation. In this article, we compute the degree of second order coherence ( (0)) of the upconverted mid-infrared field under realistic parameters and accounting for the anharmonic potential that characterizes vibrational modes of individual molecules.
View Article and Find Full Text PDFJ Biol Methods
November 2024
Department of Medicine and Surgery, University of Enna Kore, Enna 94100, Italy.
Background: Anterior uveitis is a common manifestation in individuals with rheumatic conditions such as spondylarthritis, Behçet's syndrome, juvenile idiopathic arthritis, and sarcoidosis. Clinical differentiation between granulomatous and non-granulomatous corneal endothelial exudates is crucial to subsequent diagnosis and treatment. Anterior segment optical coherence tomography (AS-OCT) can ensure an accurate differential diagnosis and appropriate follow-up after local and systemic therapy.
View Article and Find Full Text PDFBMC Ophthalmol
January 2025
Dept. of Retina and Vitreous, Narayana Nethralaya, #121/C, 1st R Block, Chord Road, Rajaji Nagar, Bengaluru, 560010, India.
Purpose: To report a rare case of a Coats-like response developing after vitreoretinal surgery for proliferative diabetic retinopathy (PDR) and its successful management with retinal laser photocoagulation and adjunctive intravitreal steroids.
Case Description: A 52-year-old woman with a five-year history of type 2 diabetes mellitus and hypertension presented with decreased vision in the left eye (counting fingers at 1 m). Examination revealed high-risk PDR in both eyes, with a subtotal macula-off combined retinal detachment in the left eye.
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