Acta Photonica Sinica, Volume. 53, Issue 8, 0814005(2024)
Laser Wireless Transmission System with Electric Output of 461 W
Laser wireless energy transmission system is a new power supply technology, which uses high-energy laser beam as energy carrier, photovoltaic cells for photoelectric conversion and non-contact energy transmission in space. In the scene with high air humidity and salinity, the traditional plug-in power supply method is used to supply power to electrical equipment, which has great security risks and the equipment is vulnerable to electromagnetic interference. The laser wireless energy transmission system can realize safety in the same working environment and provide high-power electric energy for electrical equipment. The laser wireless energy transmission system consists of a transmitter and a receiver. The volume and weight of the receiving end of the system are strictly limited by the carrier in most applications, and the photoelectric efficiency of the receiving end of the high-power laser wireless energy transmission system will be far less than the measured value in the laboratory due to the low duty ratio of the photosensitive surface, the influence of the circuit efficiency on the illumination distribution of the light spot and the temperature increase caused by continuous illumination. In order to eliminate the influence of the above three factors, the conventional methods include photovoltaic cell arrangement, large-aperture focusing lens reception, heat sink and fan cooling, etc, but there are still some shortcomings such as complicated arrangement, mismatched shapes and heavy weight of the receiving end. Aiming at the above problems, a set of high-power laser wireless energy transmission system is developed. The transmitting end of the system consists of two 808 nm semiconductor lasers, an optical fiber coupling lens, a square-core optical fiber and an object telecentric projection lens. The transmitter uses square-core fiber to homogenize Gaussian beam. A projection lens is designed by using the "positive-positive-negative" structure. The three lenses of the projection lens are all spherical mirrors made of JGS1 material. The front end of the lens is 60 mm away from the optical fiber port, and the total length of the system is 100 mm. The half-height of 0.5 mm corresponds to 209.86 mm and the half-height of 0.707 mm corresponds to 297.48 mm. When the object NA=0.17, the minimum luminous radius of the system lens is 10.32 mm. The geometric speckle is within the diffraction limit, and the maximum relative distortion is 0.025%. The laser spot of 1 mm×1 mm can be projected to 25 m, and the spot size is 420 mm×420 mm. The lens barrel of the projection lens of the projection lens is made of aluminum alloy, and the radiating fins are added on the outer side to facilitate the overall heat dissipation. In order to improve the duty ratio of photosensitive surface of single photovoltaic cell, an integrated lens-photovoltaic cell packaging method is proposed. The light irradiated on the electrodes and gaps around the photosensitive surface is focused on the photosensitive surface by the lens, and the material is optical plastics, and then it is integrated with the battery by injection molding. The high-power laser wireless energy transmission system developed in this paper can generate a high-power square uniform spot by shaping the square-core fiber at the transmitter. A projection optical system is designed to enlarge the outgoing end face of the square-core fiber and irradiate it on the 420 mm×420 mm photovoltaic panel with matching shape, which reduces the difficulty of arranging the photovoltaic array at the receiver. By using the lens-photovoltaic integrated packaging technology, 1 024 GaAs photovoltaic cells were integrated and packaged with the focusing lens at the receiving end, and the duty cycle of the single photovoltaic cell was increased to 96.5%, which was 13.15% higher than that of the traditional photovoltaic cell packaging method, effectively solving the problem of low duty cycle of the photosensitive surface. The experimental results show that when the incident laser power is 1 700 W, the electronic load terminal receives 461 W of electric power, and the overall photoelectric conversion efficiency of the receiving terminal is 27.1%. It can provide a solution for wireless power supply of high-power load in specific environment.
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Fanglei YU, Zhaoran ZOU, Xiangxiang MENG, Yue PENG, Jingang ZHANG. Laser Wireless Transmission System with Electric Output of 461 W[J]. Acta Photonica Sinica, 2024, 53(8): 0814005
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Received: Dec. 18, 2023
Accepted: Apr. 13, 2024
Published Online: Oct. 15, 2024
The Author Email: MENG Xiangxiang (mengxx326@126.com)