Abstract: A mobile video and audio box control system includes a television (TV) stick, a video splitter, a converter of High Definition Multimedia Interface (HDMI) to DisplayPort (DP), an interface of HDMI to red, green, and blue (RGB), a sub screen, a Micro Control Unit (MCU) circuit, a power management circuit, and a power circuit. The TV stick transmits the video and audio signals to the converter of HDMI to DP and the interface of HDMI to RGB by the video splitter, and the interface of HDMI to RGB transmits the video and audio signals to the sub screen; the MCU circuit is configured to control the interface of HDMI to RGB; the power management circuit is configured to supply power. The system is integrated and stable, and users can watch video and audio contents anytime and anywhere. The system has easy operation, good practicability, and strong battery life.

Abstract: A Volume Bragg grating (VBG) is placed in the back of a collimating lens, the incident angle between exposure light beam and the Volume Bragg grating is equal to the Bragg angle of the Volume Bragg grating. A photodetector is placed in the ?1 grade transmission diffraction light path of the Volume Bragg grating which the exposure light beam is emitted to. The pinhole filter is moved back and forth along an optical axis and the reading of the photodetector is observed in real time. When the reading of the photodetector is maximum, fix the pinhole filter and keep the distance between the first pinhole filter and the first collimating lens a constant. The method for adjusting the self-collimation optical path is provided, using the Volume Bragg grating to detect the parallelism of self-collimation light and substituting for a traditional Moire pattern adjustment method.

Abstract: A Volume Bragg grating (VBG) is placed in the back of a collimating lens, the incident angle between exposure light beam and the Volume Bragg grating is equal to the Bragg angle of the Volume Bragg grating. A photodetector is placed in the ?1 grade transmission diffraction light path of the Volume Bragg grating which the exposure light beam is emitted to. The pinhole filter is moved back and forth along an optical axis and the reading of the photodetector is observed in real time. When the reading of the photodetector is maximum, fix the pinhole filter and keep the distance between the first pinhole filter and the first collimating lens a constant. The method for adjusting the self-collimation optical path is provided, using the Volume Bragg grating to detect the parallelism of self-collimation light and substituting for a traditional Moire pattern adjustment method.

Abstract: This invention discloses a method for fabricating a holographic grating with low diffractive wave aberrations on a substrate with aberrations. Forming a interference recording field from two coherent beams, where one is a parallel beam and the other is a beam whose wave-front can be controlled, recording the holographic field on the substrate with aberrations, fabricating the holographic grating with low diffractive wave aberrations, setting a deformable minor into one of the coherent recording beams, and controlling the shape of said deformable minor so as to obtain a compensated interference recording field. Expose the recoding plate under the holographic interference recording field which has been adjusted by the deformable minor to record the grating. After developing, the fabrication of holographic grating with low diffractive wave aberration is finished.