The present invention discloses a
plasmon enhancement based
electron emitting device and method with light enhancement / modulation. The device includes: a
package structure, a power source and a
light source, wherein the
package structure has a
cathode and an
anode; a through hole is formed in the
anode, the
cathode is disposed on a conductive substrate, and the
cathode is a field-emission cathode constituted by a cathode substrate and
metal nanostructures attached to a surface of the cathode substrate; the power source forms an
electric field between the cathode and the
anode; and the
light source emits
laser light incident on the
metal nanostructures of the cathode through the through hole of the anode. In the light enhancement / modulation
electron emission device of the present invention, the incident light emitted by the
light source causes enhancement of the
electron emission of the field-emission cathode which is formed by combination of field-emission material of the cathode substrate and the
metal nanostructures, so that the electron
emission efficiency is increased. Meanwhile, by changing the intensity,
wavelength and polarization of the incident
laser, a
local field of the surface of the field-emission material is adjusted, and light modulating electron emission is achieved.