Photon statistics of a single mode of spontaneous Raman scattering in a distributed Raman amplifier
Experimental measurement of spontaneous noise statistics from a distributed Raman amplifier has been achieved with single-mode and single-photon resolution. The results agree with quantum theoretical predictions of a Bose-Einstein probability distribution. Distributed Raman amplification is becoming increasingly important in today's optical communication systems. It improves the optical signal-to-noise ratio by providing optical gain inside the transmission fiber.
Спектроскопічні особливості профілів ВКР підсилення в одномодових волокнах на основі кварцового скла
The spectroscopic analysis of the frequency distribution of the amplification of optical radiation due to the Raman effect (Raman gain profile) in single-mode fibers based on silica glass has been carried out in the region of Stokes frequency shifts from 0 to 1400 cm−1. The Raman gain profiles are determined from the experimental spectra of spontaneous scattering for widespread fibers, namely for pure SiO2, GeO2, P2O5, and TiO2 doped fibers. The analytic expressions of the Raman gain profiles are given. They are obtained, by using the Gaussian decomposition by means of 11–12 modes, and the experimental profile is approximated with an accuracy of not less than 0.3%. The decomposition results are analyzed in terms of the fundamental oscillatory dynamics of molecular nanocomplexes in amorphous glass, as well as in the application aspect of the modeling of photonics devices. Examples of the proposed method applications are presented for the analysis of noise parameters of the fiber Raman amplifiers and for the generation bandwidth in fiber Raman lasers.
The MR-TOF-MS isobar separator for the TITAN facility at TRIUMF
At TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) will extend TITAN’s capabilities and facilitate mass measurements and in-trap decay spectroscopy of exotic nuclei that so far have not been possible due to strong isobaric contamination. This MR-TOF-MS will also enable mass measurements of very short-lived nuclides (half-life > 1 ms) that are produced in very low quantities (a few detected ions overall). In order to allow the installation of an MR-TOF-MS in the restricted space on the platform, on which the TITAN facility is located, novel mass spectrometric methods have been developed. Transport, cooling and distribution of the ions inside the device is done using a buffer gas-filled RFQ-based ion beam switchyard. Mass selection is achieved using a dynamic retrapping technique after time-of-flight analysis in an electrostatic isochronous reflector system. Only due to the combination of these novel methods the realization of an MR-TOF-MS based isobar separator at TITAN has become possible. The device has been built, commissioned off-line and is currently under installation at TITAN.