A novel phase shifter design for carrier depletion based silicon modulators, based on an experimentally validated model, is described. It is believed that the heretofore neglected effect of incomplete ionization will have a significant impact on ultra-responsive phase shifters. A low VL product of 0.3 V.Math.cm associated with a low propagation loss of 20 dB/cm is expected to be observed. The phase shifter is based on overlapping implantation steps, where the doses and energies are carefully chosen to utilize counter-doping to produce an S-shaped junction. This junction has a particularly attractive VL figure of merit, while simultaneously achieving attractively low capacitance and optical loss. This improvement will enable significantly smaller Mach-Zehnder modulators to be constructed that nonetheless would have low drive voltages, with substantial decreases in insertion loss. The described fabrication process is of minimal complexity; in particular, no high-resolution lithographic step is required.

A method includes forming a layer made of a first insulating material on a first layer made of a second insulating material that covers a support, defining a waveguide made of the first material in the layer of the first material, covering the waveguide made of the first material with a second layer of the second material, planarizing an upper surface of the second layer of the second material, and forming a single-crystal silicon layer over the second layer.

Photonics has become a dominant or evolving technological solution for communications to meet the increasing demand for bandwidth. Accordingly, photonic communications is moving towards coherent modulation formats to further increase capacity by encoding information in both phase and amplitude of the optical signal. Whilst coherent optical transmitters and coherent optical receivers are more complex than their on-off counterparts leveraging monolithic photonic elements and photonic integrated circuits employing said photonic elements offers a lower cost route for coherent optical components. Further, external modulation, using phase modulators or amplitude modulators or a combination thereof, can increase modulation bandwidth relative to directly modulated lasers for increased data transmission. Novel optical hybrid circuits and external modulators are present which are compatible photonic integrated circuit manufacturing techniques and monolithic integration.

Provided is a silicon-based electro-optic modulator which is small in size and capable of high speed operation. A first silicon semiconductor layer (120) doped to exhibit a first type of conductivity and a second semiconductor layer (160) doped to exhibit a second type of conductivity are at least partly stacked together, and a relatively thin dielectric (150) is formed at the interface between the stacked first and second silicon semiconductor layers (120, 160). The first silicon semiconductor layer (120) has a rib waveguide shape (130) comprising a rib portion (131) and slab portions (132). A first heavily doped region (140) formed by a high concentration doping process is arranged at a location, in the first silicon semiconductor layer (120), neighboring to each of the slab portions (132). The first heavily doped region (140) has almost the same height as that of the rib portion (131) of the rib waveguide (130).

A novel phase shifter design for carrier depletion based silicon modulators, based on an experimentally validated model, is described. It is believed that the heretofore neglected effect of incomplete ionization will have a significant impact on ultra-responsive phase shifters. A low VL product of 0.3 V.Math.cm associated with a low propagation loss of 20 dB/cm is expected to be observed. The phase shifter is based on overlapping implantation steps, where the doses and energies are carefully chosen to utilize counter-doping to produce an S-shaped junction. This junction has a particularly attractive VL figure of merit, while simultaneously achieving attractively low capacitance and optical loss. This improvement will enable significantly smaller Mach-Zehnder modulators to be constructed that nonetheless would have low drive voltages, with substantial decreases in insertion loss. The described fabrication process is of minimal complexity; in particular, no high-resolution lithographic step is required.

An electro-optically coupled switch includes first and second waveguides which are aligned in parallel to each other, with a thin, flat layer of cross-coupling material sandwiched therebetween. A voltage source is provided to establish a strong uniform electric field that is oriented perpendicular across the entire layer of cross-coupling material between the waveguides. Incorporated with the voltage source is a switch for changing the electric field, to thereby alter the refractive index of the cross-coupling material for transferring the transmission of an optical signal from one waveguide to the other.

An electro-optical device includes a waveguide and a first electrode and a second electrode. The first electrode and the second electrode at first and second sides of the waveguide, wherein the first electrode and the second electrode directly contact and extend beyond the first and second sides of the waveguide respectively.

A package comprises a photonic integrated circuit (PIC) with a modulator having a first modulator input, and a PIC interconnect region within two millimeters or fifty microns from the modulator. Additionally, an electric integrated circuit (EIC) is included with a driver circuit and an EIC interconnect region within two millimeters or fifty microns from the driver circuit. The driver circuit is electrically connected to the first modulator input via the EIC interconnect region, a first metal interconnect, and the PIC interconnect region. The modulator receives a temperature-dependent bias voltage, where the temperature dependence of the bias voltage inversely matches the temperature dependence of the modulator across an extended temperature range.

A metalens and methods of manipulating light using a metalens are provided. In some aspects, a metalens comprises a slab or substrate and a plurality of regions or features distributed on the slab. In some instances, the slab can be formed from a material having a first refractive index, and the plurality of regions can be formed from a material having a second refractive index. In some instances, the first refractive index can be higher than the second refractive index, and in some aspects, the plurality of regions define an optical modulation or manipulation structure for light having a target wavelength or the target range of wavelengths .

Provided is an optical waveguide, comprising: an optical propagation path containing an organic electro-optic polymer material; and a stacked structure covering at least a portion of the optical propagation path, having a first layer to prevent oxygen from permeating into the optical propagation path from outside, and a second layer to prevent moisture from permeating into the first layer from the outside. The first layer may contain Al.sub.2O.sub.3, and the second layer may contain SiO.sub.2. The stacked structure may have a three-layer structure consisting of the second layer, the first layer, and a third layer that prevents moisture permeation from the optical propagation path to the first layer, stacked in sequence.