Highly sensitive Raman gain coefficient measurement by detecting spontaneous Raman scattering power for distributed Raman amplification systems

Raman Spectra of a PMMA Microstructured Optical Fibre and Direct Measurement of Its Gain Coefficient

 A polymethylmethacrylate (PMMA) microstructured polymer optical fiber (mPOF) is fabricated and characterized. Using the cut-back technique the fiber loss is measured which is higher than the step-index silica fibers. Through a novel experimental scheme, the backward Stokes spectrum of the fabricated mPOF is recorded over a range exceeding 3000 cm‑1 during the cut-back method and compared ...

Macroscale Plasmonic Substrates for Highly Sensitive Surface-Enhanced Raman Scattering**

Analysis of distributed temperature sensing based on Raman scattering using OTDR coding and discrete Raman amplification

The behaviour of distributed temperature sensors based on spontaneous Raman scattering and coded OTDR (optical time domain reflectometry) is studied both theoretically and experimentally; in particular a high performance scheme has been implemented using amplitude modulation according to Simplex coding, direct detection and additional use of lumped Raman amplification to further extend the sens...

Hybrid gain-flattened and reduced power excursion scheme for distributed Raman amplification.

We propose and evaluate through extensive numerical modelling a novel distributed hybrid amplification scheme combining first and second-order Raman pumping which gives reduced signal power excursion over a wide spatial-spectral range of 60 km × 80 nm in C + L-bands.

Spontaneous and stimulated X-ray Raman scattering

The present thesis is devoted to theoretical studies of resonant X-ray scattering and propagation of strong X-ray pulses. In the first part of the thesis the nuclear dynamics of different molecules is studied using resonant X-ray Raman and resonant Auger scattering techniques. We show that the shortening of the scattering duration by the detuning results in a purification of the Raman spectra f...