graphene oxide (GO) and reduced graphene oxide (rGO) were demonstrated by manipulating its oxygen content using direct laser writing (DLW) method. The overall lens thickness potentially can be reduced by more than ten times. Also, the linear optical absorption of GO increases as the reduction of GO deepens, which results in transmission contrast between GO and rGO and therefore provides an amplitude modulation mechanism. Moreover, both the refractive index and optical absorption are dispersionless over a wavelength range from visible to near infrared. GO film offers flexible patterning capability by using the maskless DLW method, which reduces manufacturing complexity. A novel ultrathin planar lens on a GO thin film used the DLW method. Its advantage is that phase modulation and amplitude modulation can be achieved simultaneously, which are attributed to the giant refractive index modulation and the variable linear optical absorption of GO during its reduction process, respectively. Due to the enhanced wavefront shaping capability, the lens thickness is subwavelength scale (~200 nm), which is thinner than dielectric lenses (~ µm scale). The focusing intensities and the focal length can be controlled effectively by varying laser power and lens size, respectively. By using oil immersion high numerical aperture (NA) objective during DLW process, 300 nm fabrication feature size on GO film has been realized, and therefore the minimum lens size reached 4.6 µm in diameter, the smallest planar micro lens. This can only be realized with metasurface by FIB. Thereafter, the focal length can be reduced to as small as 0.8 µm, which would potentially increase the NA and the focusing resolution. The full-width at half-maximum (FWHM) of 320 nm at the minimum focal spot using a 650 nm input beam has been demonstrated experimentally, which corresponds to an effective NA of 1.24 (n=1.5). Furthermore, ultra-broadband focusing capability from 500 nm to as far as 2 µm have been realized with this planar lens. Nanoantennas The first flat lens used a thin wafer of silicon 60 nanometers thick coated with concentric rings of v-shaped gold nanoantennas to produce photographic images. The antennas refract the light so that it all ends up on a single focal plane, a so-called artificial refraction process. The antennas were surrounded by an opaque silver/titanium mask that reflected all light that did not strike the antennas. Varying the arm lengths and angle provided the required range of amplitudes and phases. The distribution of the rings controls