Photoluminescence spectra of an optically pumped erbium-doped micro-cavity with SiO2/TiO2 distributed Bragg reflectors

We investigate the spectral properties of an optically pumped micro-cavity made of a half-wavelength erbium-doped SiO2 layer sandwiched between two six-period SiO2/TiO2 distributed Bragg reflectors. The structure, grown by the rf-sputtering technique, is characterised by its transmittance and photoluminescence (PL) spectra. The pump laser operates at λP=514.5 nm under optimized oblique incidence. Extended (3×3) transfer matrix formalism including sources leads to an analytical description of the spectral and angular properties of the emitted field, for both states of polarization. As expected, a pronounced enhancement of the PL emission around the cavity resonance is observed.