Abstract: A solar cell, a method for preparing the same and an electrical device are provided. The method for preparing the solar cell includes following steps: providing a substrate, which includes a first surface and a second surface opposite to the first surface; forming a protective material layer on the first surface, and removing part of the protective material layer on a preset first doped region to prepare a protective layer; performing a first doping process in the preset first doped region on the substrate to prepare a substrate including a first doped region. A width of the first doped region is in a range of 10 ?m to 35 ?m.

Abstract: An optical signal amplification apparatus includes a power detection module, a pump control module, and a Raman amplification module. The power detection module is configured to detect power of each of a plurality of G wavelength channels in each of a plurality of N spatial dimensions, and send power configuration information to the pump control module. The pump control module is configured to output N channels of pump light, where each channel of pump light includes M pieces of split pump light of different wavelengths, and a proportion of each piece of split pump light in pump light of a corresponding wavelength is determined based on the power configuration information. The Raman amplification module is configured to perform Raman amplification on a space division multiplexed signal in all of the N spatial dimensions by using the N channels of pump light.