Abstract: A tunable external cavity laser with dual gain chips, including: a polarization beam splitter having a beam splitting surface arranged at an angle of 45° with respect to a first direction and a second direction perpendicular to the first direction; a first gain chip arranged in the first direction; a second gain chip arranged in the second direction; a feedback cavity arranged in the first direction, wherein the feedback cavity and the first gain chip are respectively arranged on two opposite sides of the polarization beam splitter, and the feedback cavity includes at least one independent Fabry-Perot etalon, at least one air gap Fabry-Perot cavity and a mirror that are arranged in the first direction. The polarization beam splitter and the two gain chips cooperate to share the feedback cavity, so that a wavelength and a phase may be adjusted, and a larger tuning range may be obtained.

Abstract: The present disclosure provides a method and system for constructing a digital rock, and relates to the technical field of digital rocks. According to the method, a three-dimensional (3D) digital rock image that can reflect real rock information is obtained using an image scanning technology, and the image is preprocessed to obtain a digital rock training image for training a generative adversarial network (GAN). The trained GAN is stored to obtain a digital rock construction model. The stored digital rock construction model can be directly used to quickly construct a target digital rock image. This not only greatly reduces computational costs, but also reduces costs and time consumption for obtaining high-resolution sample images. In addition, the constructed target digital rock image can also reflect real rock information.

Abstract: An oil cooling system for an electric machine that includes a housing and a stator accommodated in the housing, the stator having a first end part and a second end part in an axial direction of the electric machine. The oil cooling system includes an oil inlet, for receiving external cooling oil; a first annular oil application pipe, located at the first end part and in fluid communication with the oil inlet; and a second annular oil application pipe, located at the second end part and in fluid communication with the oil inlet. An axial oil application part is located between the first end part and the second end part and formed by a housing inner wall and a stator outer wall. The axial oil application part receives cooling oil from at least one of the first annular oil application pipe and the second annular oil application pipe.

Abstract: A broadband tuning system includes a first chip and a second chip. The first chip includes a first light amplification region, a first forward grating region and a first backward grating region that are sequentially arranged in a first direction. The first light amplification region is configured to amplify a first light source and to turn on or turn off the first light source, and the first forward grating region and the first backward grating region are configured to tune the first light source. The second chip includes a second light amplification region, a second forward grating region and a second backward grating region that are sequentially arranged in a second direction. The second light amplification region is configured to amplify a second light source and to turn on or turn off the second light source, and the second forward grating region and the second backward grating region are configured to tune the second light source.

Abstract: A tunable external cavity laser with dual gain chips, including: a polarization beam splitter having a beam splitting surface arranged at an angle of 45° with respect to a first direction and a second direction perpendicular to the first direction; a first gain chip arranged in the first direction; a second gain chip arranged in the second direction; a feedback cavity arranged in the first direction, wherein the feedback cavity and the first gain chip are respectively arranged on two opposite sides of the polarization beam splitter, and the feedback cavity includes at least one independent Fabry-Perot etalon, at least one air gap Fabry-Perot cavity and a mirror that are arranged in the first direction. The polarization beam splitter and the two gain chips cooperate to share the feedback cavity, so that a wavelength and a phase may be adjusted, and a larger tuning range may be obtained.

Abstract: A broadband tuning system includes a first chip and a second chip. The first chip includes a first light amplification region, a first forward grating region and a first backward grating region that are sequentially arranged in a first direction. The first light amplification region is configured to amplify a first light source and to turn on or turn off the first light source, and the first forward grating region and the first backward grating region are configured to tune the first light source. The second chip includes a second light amplification region, a second forward grating region and a second backward grating region that are sequentially arranged in a second direction. The second light amplification region is configured to amplify a second light source and to turn on or turn off the second light source, and the second forward grating region and the second backward grating region are configured to tune the second light source.