COSMA: Coherent Optics Sensors for Medical Application is an European Marie Curie Project running from 2012 to March 2016, with the participation of 10 teams from Armenia, Bulgaria, India, Israel, Italy, Poland, Russia, UK, USA. The main objective was to focus theoretical and experimental research on biomagnetism phenomena, with the specific aim to develop all-optical sensors dedicated to their detection and suitable for applications in clinical diagnostics. The paper presents some of the most recent results obtained during the exchange visits of the involved scientists, after an introduction about the phenomenon which is the pillar of this kind of research and of many other new fields in laser spectroscopy, atomic physics, and quantum optics: the dark resonance.
The dynamics of Light-Induced Atomic Desorption (LIAD) in 6 cells with different coatings (PDMS coated cells prepared with two different concentrations of PDMS in ether, SC-77, PCHS, DCDMS, OTS) is investigated. The rates of desorption and adsorption of the Rb atoms when the illuminating light is switched ON and OFF and their dependence on the illuminating blue-light power are measured. The influence of the homogeneity of illumination for increasing the desorption and adsorption rates is evaluated. The results are interesting for the better understanding of LIAD and its dynamics and for the development of new optoelectronic elements, LIAD-loaded atomic devices and their miniaturization, and new methods for surface and coating diagnostics.
In this work we present new features observed in the Saturated Absorption (SA) spectrum on the D1 line of K. In an
uncoated optical glass cell containing pure K atoms, excitation by circularly polarized pump beam produces an
enhancement of the amplitude of the crossover resonances due to the hyperfine transitions starting from the ground state
Fg = 2. This effect appears to be much more relevant when K atoms are contained in a cell coated with an anti-relaxation
film. Here, the crossover resonance in the Fg = 2 set of transition is not observed experimentally with linearly polarized
pump light, while in case of circular polarization its amplitude is significantly enlarged. The Light Induced Atomic
Desorption (LIAD) effect strongly improves the intensities of the SA resonances observed in coated cell.