Reflective silicon binary diffraction grating for visible wavelengths

Diffraction properties of transmission binary blazed grating

The properties of binary blazed grating were theoretically analyzed with finite-difference time -domain (FDTD) method. The diffraction efficiencies and diffraction angles of –1, 0, and +1 order for the grating varying with wavelength, grating structure, and the etch depth were studied when the incident angle was 30°. The numerical simulations revealed that the binary blazed grating presented hi...

Polarizing diffraction-grating triplicators.

We report experimental results with a reflective continuous anisotropic polarizing diffraction-grating beam splitter that produces three diffraction orders. The diffraction efficiencies and polarizations of the diffracted orders are controlled through the incoming polarization state and by use of a wave plate with arbitrary orientation located between the grating and a mirror. In particular, we...

Grating-coupled silicon-on-sapphire integrated slot waveguides operating at mid-infrared wavelengths.

We demonstrate subwavelength bidirectional grating (SWG) coupled slot waveguide fabricated in silicon-on-sapphire for transverse electric polarized wave operation at 3.4 μm wavelength. Coupling efficiency of 29% for SWG coupler is experimentally achieved. Propagation loss of 11  dB/cm has been experimentally obtained for slot waveguides. Two-step taper mode converters with an insertion loss of ...

Metalenses at visible wavelengths: Diffraction-limited focusing and subwavelength resolution imaging.

Subwavelength resolution imaging requires high numerical aperture (NA) lenses, which are bulky and expensive. Metasurfaces allow the miniaturization of conventional refractive optics into planar structures. We show that high-aspect-ratio titanium dioxide metasurfaces can be fabricated and designed as metalenses with NA = 0.8. Diffraction-limited focusing is demonstrated at wavelengths of 405, 5...

The Diffraction Grating