4results about How to "Wide gain bandwidth" patented technology

The application discloses a preparation method of a near-infrared vertical cavity surface laser with low threshold and high gain based on weakly confined quantum dots, and belongs to the technical field of quantum dot lasers. A CdS shell layer is grown on the weakly confined double-tapered CdSe quantum dots, and the thickness of the CdS shell layer is controlled to be 2 layers by controlling the injection amount of dodecanethiol; the CdSe / CdS quantum dots are spin-coated on the high-reflection surface of two Bragg reflectors (DBRs); and the surfaces coated with the quantum dots are close to each other and are spliced to form a vertical cavity surface laser. The vertical cavity surface laser constructed by taking the weakly confined double-tapered hexahedral CdSe / CdS quantum dots as deep red gain material has deep red / near-infrared laser emission of 720 nm, an extremely low laser threshold of 11.23 µJ / cm 2 and an extremely wide gain bandwidth of 670-730 nm.

The invention discloses an ultra-wideband high-gain vortex optical fiber with a composite structure and a preparation method of the ultra-wideband high-gain vortex optical fiber. The optical fiber sequentially comprises a passive fiber core, an active inner ring core, an active outer ring core and a cladding from inside to outside. The passive fiber core is an optical material or an air hole which is not doped with active ions; the active inner ring core and the active outer ring core are made of laser materials doped with different rare earth light-emitting ions, and different light-emitting wave bands correspond to different rare earth light-emitting ion combination modes, for example, the blue light wave band is Tb-Tm, the red light wave band is Eu-Sm, the 1-micron wave band is Nd-Yb, the 1.5-micron wave band is Er-Tm, the 2-micron wave band is Tm-Ho, and the 3-micron wave band is Er-Ho or Er-Dy. According to the structure composite vortex optical fiber, rare earth light-emitting ions are doped in a partitioned mode, the unnecessary energy transfer process can be effectively avoided, the light-emitting efficiency of the optical fiber is improved, the light-emitting bandwidth of the optical fiber is increased, and the structure composite vortex optical fiber is applied to a high-performance vortex optical fiber laser and a broadband orbital angular momentum multiplexing system.

The invention discloses a circularly polarized high-gain lens antenna for improving axial ratio bandwidth and gain bandwidth, which belongs to the technical field of antenna engineering, is applied to the fields of self-satellite communication and the like, and has the characteristics of wide frequency band (axial ratio bandwidth and gain bandwidth), high gain and easiness in processing. The circularly polarized lens part adopted by the invention is easy to process by means of a 3-D printing technology, and is easy to integrate with a linear polarization feed source. The dielectric lens unit has dual functions of a circular polarizer and a phase shifter, and can improve the gain of the antenna. The phase shifters with different lengths can provide all-phase compensation for the lens antenna, and the circular polarizer can convert linearly polarized waves into circularly polarized waves. Compared with a reported dielectric circularly polarized antenna, the antenna provided by the invention has wider axial ratio bandwidth and gain bandwidth. According to the invention, a lens antenna scheme with low processing complexity, wide band and high gain is realized in the application field of millimeter wave antennas.

The present invention discloses an integrated high-gain metal lens horn antenna, comprising a metal feed horn and a metal lens; the metal feed horn comprises a horn-shaped metal wall and a feed waveguide arranged at the feed end of the horn-shaped metal wall; the radiation aperture end of the metal feed horn and the metal lens form an integrated structure to completely confine the electric field distribution of the transmitted electromagnetic wave within the integrated structure. Compared with other dielectric horn antennas, the present invention can have a higher power capacity and effectively improve the aperture efficiency of the antenna.