Abstract: The technology of this application relates to an erbium-doped fiber. The erbium-doped fiber can be used in the fields of amplifiers, optical communications, rare-earth-doped fiber preparation, and the like. A fiber core of the erbium-doped fiber includes a first layer and a second layer from inside to outside. The first layer includes a center of the fiber core. The second layer is an annulus, and an outer ring of the annulus is an outer ring of the fiber core. An average doping concentration of erbium ions of the first layer is higher than an average doping concentration of erbium ions of the second layer. An ASE can be reduced by reducing a doping concentration of erbium ions of the second layer, to further reduce a noise figure of the erbium-doped fiber and improve communications quality.

Abstract: A method and apparatus for storing data are provided. The method comprises: obtaining a dataset to be stored and a storage model, wherein said dataset comprises a source storage parameter, and the storage model comprises a target storage parameter; in response to determining that the source storage parameter is consistent with the target storage parameter, obtaining a storage key value of said dataset; obtaining raw data that is written into said dataset for the first time and corresponds to the source storage parameter and change data that is in said dataset and corresponds to the source storage parameter; and storing the raw data and the change data in the storage model according to the storage key value.

Abstract: An erbium-doped optical fiber includes a fiber core, where the fiber core includes erbium ions, aluminum ions, phosphorus ions, lanthanum ions, antimony ions, and silicon ions. A mass percentage of the erbium ions ranges from 0.25 percentage by weight (wt %) to 0.6 wt %, a mass percentage of the aluminum ions ranges from 3 wt % to 6 wt %, a mass percentage of the phosphorus ions ranges from 7 wt % to 16 wt %, a mass percentage of lanthanum ions ranges from 0.5 wt % to 1.2 wt %, a mass percentage of antimony ions ranges from 1 wt % to 5 wt %, and a mass percentage of silicon ions is greater than 60 wt %.

Abstract: A method for controlling a histotripsy using a confocal fundamental and harmonic superposition combined with hundred-microsecond ultrasound pulses, including: 1) positioning a target tissue by a monitoring and guiding system and adjusting a position of the target tissue to a focal point of a transducer; 2) first stage: controlling the confocal fundamental and harmonic superposition combined with hundred-microsecond ultrasound pulses to form a shock wave in a focal zone; wherein a negative acoustic pressure exceeds a cavitation threshold; an inertial cavitation occurs to generate boiling bubbles; the boiling bubbles collapse and achieve partial homogenization of the target tissue; 3) second stage: controlling the confocal fundamental and harmonic superposition combined with hundred-microsecond pulsed-ultrasound sequences to simultaneously irradiate a target zone and further mechanically disintegrate and homogenize the target tissue.

Abstract: A method for controlling a histotripsy using a confocal fundamental and harmonic superposition combined with hundred-microsecond ultrasound pulses, including: 1) positioning a target tissue by a monitoring and guiding system and adjusting a position of the target tissue to a focal point of a transducer; 2) first stage: controlling the confocal fundamental and harmonic superposition combined with hundred-microsecond ultrasound pulses to form a shock wave in a focal zone; wherein a negative acoustic pressure exceeds a cavitation threshold; an inertial cavitation occurs to generate boiling bubbles; the boiling bubbles collapse and achieve partial homogenization of the target tissue; 3) second stage: controlling the confocal fundamental and harmonic superposition combined with hundred-microsecond pulsed-ultrasound sequences to simultaneously irradiate a target zone and further mechanically disintegrate and homogenize the target tissue.