▎ 摘　　要

NOVELTY - The planar lens focusing device comprises a base layer (101). A molybdenum oxide thin layer (102) is arranged on the upper side of the base layer. A silicon substrate is arranged on the lower side of the base layer. A metal antenna (103) covers the upper side of the molybdenum oxide thin layer, or the metal antenna is embedded between the lower side of the molybdenum oxide thin layer and the base layer. A graphene layer covers an upper layer of the molybdenum oxide thin layer. The graphene layer and the silicon substrate are connected to a voltage. The metal antenna excites hyperbolic phonon excimers. The Fermi level of the graphene layer is changed by the voltage to adjust the focal length for nano-focusing. The voltage is connected between the graphene layer and the silicon substrate. The Fermi level of the graphene layer is changed by changing the voltage, and the position of the focal length is dynamically adjusted to adjust the focal length with which the planar lens focuses. USE - Planar lens focusing device for adjusting focus for nano-focusing of planar lens. ADVANTAGE - The device is capable of adjusting the focal length of the nano-focusing by changing the size of the metal antenna or the wavelength of the incident light, thus reducing the manufacturing cost of the device, and increasing the range of the collected light, and hence reducing the light loss of the device. The device is simple and easy to use, has a wide range of use, and is low cost. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a manufacturing method of a planar lens focusing device; and (2) a method for adjusting the focus for nano-focusing. DESCRIPTION OF DRAWING(S) - The drawing shows a structure schematic diagram of the planar lens focusing device. Base layer (101) Molybdenum oxide thin layer (102) Metal antenna (103) Incident infrared light (104) Scanning near field optical microscope needle tip (105)