Name: María Hernández (thesis defended the 01/07/2020).

Title: “Estudio de cavidades de alta fineza para la medida de precisión de láseres de distinta naturaleza: aplicaciones en metrología cuántica”.

Abstract: This Bachelor thesis has been devoted to study the most relevant aspectsregarding regulation and reduction of the laser linewidth for optical transitions. For this, the techniques in use like PID and Pound Drever Hall for regulation and linewidth reduction, respectively, have been studied in detail using a titanium sapphire (Ti:Sa) laser and a low-finesse cavity existing in the laboratory. This will allow to make later practicable the procedure/techniques using instead a high-finesse cavity. The high-finesse cavity will be available in 2020. At that time, this experimental work focused on designing a setup, will make possible to reach the quantum regime in the experiments carried out at the Ion Traps and Lasers Laboratory at the University of Granada. The use of the frequency comb will be needed in the envisaged experiments of quantum nature; metrology and simulations using the ”clock transition” in 40Ca+. However, without the high-finesse cavity, a new application of the comb has been developed in this work. This consists in regulating one of the transition in 40Ca+ providing at the same time a reference for the other transitions to be driven in the experiment.

Name: David Freire (thesis defended the 24/07/2020).

Title: “Detección de fluorescencia de iones de 40Ca+ en una trampa de iones”.

Abstract: Within this Bachelor Thesis, a detailed studied of the devices utilized for the detection of fluorescence photons, emitted by a laser-cooled 40Ca+ ion stored in a 7-tesla Penning trap, has been carried out. These devices are an Electron Multiplying Charge-Coupled Device (EMCCD) camera, a scientific Complementary Metal-Oxide-Semiconductor (sCMOS) camera and a Photo Multiplier Module (PMM), the latter studied together with different signal processing and acquisition systems. For the first time in the Ion Traps and Lasers Laboratory at the University of Granada, a PMM has been implemented in the Penning-traps beamline, which is complementary to the existing EMCCD camera. This has been done in such a way that it is possible to use both devices simultaneously. Different measurements have been carried out after applying the axialization technique, which is needed for laser cooling in a Penning trap, and thus to perform experiments on a small number of trapped ions. The results from the measurements have allowed determining the number of counts per second per stored ion . Besides this, the PMM allows collecting data within very short acquisition times, something that is crucial for the experiments in the quantum regime envisaged in the laboratory.