Abstract: A radiation-resistant laser optical fiber preform core rod at least includes one type of activated ion (Yb3+, Er3+) and one or more types of co-doped ion (Al3+, P5+, Ge4+, Ce3+, F?), and —OD group of 16-118 ppm. Irradiation resistance of core rod glass can be effectively improved by sequentially performing pre-treatments, i.e. deuterium loading, pre-irradiation and thermal annealing on a preform core rod. Electron paramagnetic resonance test shows that, under the same radiation condition, the radiation induced color center concentration in a preform core rod treated by the method above is lower than in an untreated core rod by one or more orders of magnitude. The obtained core rod can be used for preparing a radiation-resistant rare earth-doped silica fiber, and has the advantages of high laser slope efficiency, low background loss, being able to be used stably in a vacuum environment for a long time, for example.

Abstract: A photodarkening-resistant ytterbium-doped quartz optical fiber and a method for prpearing such a fiber are provided. Glass of a photodarkening-resistant ytterbium-doped quartz optical fiber core rod includes at least Yb2O3, Al2O3, P2O5, SiO2. The proportions of Yb2O3, Al2O3, and P2O5 in the entire substance are Yb2O3: 0.05-0.3 mol %, Al2O3: 1-3 mol %, and P2O5: 1-5 mol %, respectively. In the preparation method for the photodarkening-resistant ytterbium-doped quartz optical fiber, a sol-gel method and an improved chemical vapor deposition method are combined. By using the molecular-level doping uniformity and the low preparation loss thereof respectively, ytterbium ions, aluminum ions and phosphorus ions are effectively doped in a quartz matrix, thereby effectively solving the problems in the optical fiber of high loss, photodarkening caused by cluster or the like, and a central refractive index dip.

Abstract: A radiation-resistant laser optical fiber preform core rod at least includes one type of activated ion (Yb3+, Er3+) and one or more types of co-doped ion (Al3+, P5+, Ge4+, Ce3+, F?), and —OD group of 16-118 ppm. Irradiation resistance of core rod glass can be effectively improved by sequentially performing pre-treatments, i.e. deuterium loading, pre-irradiation and thermal annealing on a preform core rod. Electron paramagnetic resonance test shows that, under the same radiation condition, the radiation induced color center concentration in a preform core rod treated by the method above is lower than in an untreated core rod by one or more orders of magnitude. The obtained core rod can be used for preparing a radiation-resistant rare earth-doped silica fiber, and has the advantages of high laser slope efficiency, low background loss, being able to be used stably in a vacuum environment for a long time, for example.

Abstract: A photodarkening-resistant ytterbium-doped quartz optical fiber and a method for preparing such a fiber are provided. Glass of a photodarkening-resistant ytterbium-doped quartz optical fiber core rod includes at least Yb2O3, Al2O3, P2O5, SiO2. The proportions of Yb2O3, Al2O3, and P2O5 in the entire substance are Yb2O3: 0.05-0.3 mol %, Al2O3: 1-3 mol %, and P2O5: 1-5 mol %, respectively. In the preparation method for the photodarkening-resistant ytterbium-doped quartz optical fiber, a sol-gel method and an improved chemical vapor deposition method are combined. By using the molecular-level doping uniformity and the low preparation loss thereof respectively, ytterbium ions, aluminum ions and phosphorus ions are effectively doped in a quartz matrix, thereby effectively solving the problems in the optical fiber of high loss, photodarkening caused by cluster or the like, and a central refractive index dip.

Abstract: A digital displacement sensor and a displacement measuring method thereof, pertaining to the technical field of displacement sensors. The digital displacement sensor includes a housing and a circuit board, and the circuit board is arranged inside the housing. The housing is provided with a window and an opening. The circuit board is provided with a signal acquisition module, an analog front end circuit, a digital compensation circuit, and a signal output interface. The digital displacement sensor allows to alternatively fix the sensor or measured object according to the structure. The measurement can be performed as long as a relative movement between the sensor and the measured object occurs. Factors such as material of the measured object etc. are not limited, so materials such as steel belts, aluminum plates, plastics etc. can be flexibly used. Merely surfaces of the measured object need to be coated with corresponding stripes.

Abstract: A digital displacement sensor and a displacement measuring method thereof, pertaining to the technical field of displacement sensors. The digital displacement sensor includes a housing and a circuit board, and the circuit board is arranged inside the housing. The housing is provided with a window and an opening. The circuit board is provided with a signal acquisition module, an analog front end circuit, a digital compensation circuit, and a signal output interface. The digital displacement sensor allows to alternatively fix the sensor or measured object according to the structure. The measurement can be performed as long as a relative movement between the sensor and the measured object occurs. Factors such as material of the measured object etc. are not limited, so materials such as steel belts, aluminum plates, plastics etc. can be flexibly used. Merely surfaces of the measured object need to be coated with corresponding stripes.

Abstract: A predistortion processing apparatus: an auxiliary feedback module, configured to: extract a nonlinear distortion signal from an analog signal, and input an obtained feedback signal corresponding to the nonlinear distortion signal into an auxiliary model coefficient training module; the auxiliary model coefficient training module, configured to: train an auxiliary coefficient according to the feedback signal and a predistortion signal, and transmit a first auxiliary coefficient obtained through training to a predistortion processing module; a radio frequency signal feedback module, configured to extract a fundamental wave feedback signal; a predistortion model coefficient training module, configured to: train a predistortion coefficient according to the predistortion signal and the fundamental wave feedback signal, and transmit an obtained predistortion coefficient to the predistortion processing module; the predistortion processing module, configured to: perform predistortion processing on an input intermedi

Abstract: A predistortion processing apparatus: an auxiliary feedback module, configured to: extract a nonlinear distortion signal from an analog signal, and input an obtained feedback signal corresponding to the nonlinear distortion signal into an auxiliary model coefficient training module; the auxiliary model coefficient training module, configured to: train an auxiliary coefficient according to the feedback signal and a predistortion signal, and transmit a first auxiliary coefficient obtained through training to a predistortion processing module; a radio frequency signal feedback module, configured to extract a fundamental wave feedback signal; a predistortion model coefficient training module, configured to: train a predistortion coefficient according to the predistortion signal and the fundamental wave feedback signal, and transmit an obtained predistortion coefficient to the predistortion processing module; the predistortion processing module, configured to: perform predistortion processing on an input intermedi