The invention discloses a
metal antenna structure for improving the slow axis far field of a
surface emission semiconductor laser unit. The
metal antenna structure comprises a substrate, a
grating layer, an
electrical isolation layer, double-channel filler, a lower
ohmic contact layer and a sub-
wavelength metal plasma antenna, wherein the substrate is provided with a double-channel
ridge-shaped
waveguide structure, and a
laser unit active region is arranged inside a
ridge-shaped region; the
grating layer is arranged on the upper surface of the substrate; the
electrical isolation layer is arranged on the upper surface of the
grating layer, and an electric injection window is formed by breaking the position, corresponding to the
ridge-shaped region, on the upper surface of the grating layer; double channels are filled with the double-channel filler; the lower
ohmic contact layer is arranged on the lower surface of the substrate; the sub-
wavelength metal
plasma antenna is arranged on the upper surface of the
electrical isolation layer and the upper surface of the double-channel filler, and an electric injection
ohmic contact region and a light output window are formed at the same time in the mode that the position, corresponding to the ridge-shaped region, of the sub-
wavelength metal
plasma antenna is broken. The metal antenna structure effectively reduces the far field
divergence angle in the slow axis direction of the
surface emission laser unit, and realizes manufacturing of a small-
divergence-angle quasi-circular spot or even circular spot
surface emission device.