Laser Cooling of Silica Glass

Abstract

Laser cooling of a solid is achieved when a coherent laser illuminates the material in the red tail of its absorption spectrum, and the heat is carried out by anti-Stokes fluorescence of the blue-shifted photons. Solid-state laser cooling has been successfully demonstrated in several materials, including rare-earth-doped crystals and glasses. Silica glass, being the most widely used optical material, has so far evaded all laser cooling attempts. In addition to its fundamental importance, many potential applications can be conceived for anti-Stokes fluorescence cooling of silica. These potential applications range from the substrate cooling of optical circuits for quantum information processing and cryogenic cooling of mirrors in high-sensitivity interferometers for gravitational wave detection to the heating reduction in high-power fiber lasers and amplifiers. Here we report the net cooling of high-purity Yb-doped silica glass samples that are primarily developed for high-power fiber laser applications, where special care has been taken in the fabrication process to reduce their impurities and lower their parasitic background loss. The non-radiative decay rate of the excited state in Yb ions is very small in these glasses due to the low level of impurities, resulting in near-unity quantum efficiency. We report the measurement of the cooling efficiency as a function of the laser wavelength, from which the quantum efficiency of the silica glass is calculated.

References in corpus (9)

• Anti-Stokes laser cooling in bulk Erbium-doped materials
• Laser cooling of solids
• Experimental Investigations on the TMI Thresholds of Low-NA Yb-doped single mode fibers
• Improvement of the Tm3+:3H4 level lifetime in silica optical fibres by lowering the local phonon energy
• Spectroscopic Investigation of Yb-doped Silica Glass for Solid-State Optical Refrigeration
• Observation of Optical Refrigeration in a Holmium-doped Crystal
• Thermal Modeling, Heat Mitigation, and Radiative Cooling for Double-Clad Fiber Amplifiers
• Heat mitigation of a core/cladding Yb-doped fiber amplifier using anti-Stokes fluorescence cooling
• Laser Cooling Characterization of Yb-Doped ZBLAN Fiber as a Platform for Radiation Balanced Lasers

Cited by in corpus (5)

• 500 W rod-type 4x4 multi-core ultrafast fiber laser
• Laser Cooling of a Yb Doped Silica Fiber by 18 Kelvin From Room Temperature
• Doped and structured silica optical fibres for fibre laser sources
• Adaptive four-level modeling of laser cooling of solids
• Laser-induced anti-Stokes fluorescence cooling of ytterbium-doped silica glass by more than 6 Kelvin