Laser cooling silica: current status and future prospects

Recent years have seen silica emerge as a viable material for optical refrigeration with potential applications in directed energy, integrated photonics, and precision metrology. Proper characterization of potential composition profiles is vital for optimization. Here, static photoluminescence spectroscopy of a Yb, Al co-doped silica sample over the temperature range 80 K to 300 K reveals the emission lineshape is dependent on the excitation wavelength. The impact this has on extracted laser cooling parameters is discussed.