Abstract: An optical device fabrication method includes removing semiconductor material from a semiconductor substrate to form a first curved surface and a second curved surface, forming a bonding material on the first curved surface, and selectively removing semiconductor material from at least one of the first and the second curved surfaces to form one or more subwavelength structures. The semiconductor substrate has a bandgap wavelength associated with a bandgap energy of the semiconductor material. The optical device refracts certain incident electromagnetic radiation and/or filters other electromagnetic radiation. The refracted radiation includes infrared wavelengths longer than the bandgap wavelength and the filtered radiation includes wavelengths shorter than the bandgap wavelength.

Abstract: An optical apparatus including a substrate and a refractive element formed above the substrate. The refractive element including a surface with a predetermined radius of curvature, and a group of periodic structures formed on the surface configured to refract or to filter one or more wavelengths of an incident light.

Abstract: An apparatus including a waveguide region configured to guide light propagating along a first direction; a reflector region configured to reflect incident light; an interference region formed between the waveguide region and the reflector region, the interference region configured to confine at least a portion of interference light formed by the incident light and the reflected incident light; and a grating region including a grating formed on a region confining at least a portion of the interference light, the grating configured to couple at least a portion of the light along a second direction that is different from the first direction.

Abstract: An optical apparatus including a substrate and a refractive element formed above the substrate. The refractive element including a surface with a predetermined radius of curvature, and a group of periodic structures formed on the surface configured to refract or to filter one or more wavelengths of an incident light.

Abstract: An optical transmitter including two reflective regions formed at two opposite ends of an interference region along a first direction and at least three electrodes electrically coupled to the interference region, where the amount of electrical carriers inside the interference region can be modulated by changing the relative electrical fields among the three electrodes, so that the amount of photons generated inside the interference region can be modulated and resonant along the first direction and emit along a second direction that is different from the first direction.

Abstract: An apparatus including a waveguide region configured to guide light propagating along a first direction; a reflector region configured to reflect incident light; an interference region formed between the waveguide region and the reflector region, the interference region configured to confine at least a portion of interference light formed by the incident light and the reflected incident light; and a grating region including a grating formed on a region confining at least a portion of the interference light, the grating configured to couple at least a portion of the light along a second direction that is different from the first direction.

Abstract: A novel germanium (Ge) photodetector is disclosed, containing a stripe layer including Ge, a substrate supporting the stripe layer, and P and N regions, which are located inside the substrate and near opposite sides of the stripe. The stripe layer containing Ge for light absorption is operated in a slow-light mode by adding combinations of a gradual taper indent structure and a periodic indent structure to reduce light scatterings and to control light group velocity inside the stripe. Due to the slower light traveling velocity inside the stripe, the absorption coefficient of the stripe containing Ge is upgraded to be 1 to 2 orders of magnitude larger than that of a traditional bulk Ge at L band, and so the absorption coefficient reaches more than 1 dB/?m at the wavelength of 1600 nm.

Abstract: An optical device for redirecting an incident electromagnetic wave includes an interference region having a first side and a second side opposite to the first side; a grating structure arranged on a third side of the interference region; a mirror arranged at the first side. An incident electromagnetic wave is impinged into the interference region through the second side or through the grating structure or through a side opposite to the grating structure, and then a substantial portion of the incident electromagnetic wave leaves the interference region at a predetermined angle with respect to the incident direction.