Achromatic Subwavelength Grating Lens for Linear Polarized Incidence

Chromatic behavior is an important drawback for emerging planar subwavelength micro lens. In this work, a subwavelength grating lens is designed under linearly polarized incidence with achromatic behavior across the whole visible wavelength. This work also represents the design, fabrication and characterization of ultra-small micro grating lens (7 microns in size) promising for compact integrated nanophotonic devices on chip.