Various embodiments of a monolithic transceiver are described, which may be fabricated on a semiconductor substrate. The monolithic transceiver includes a coherent receiver module (CRM), a coherent transmitter module (CTM), and a local oscillation splitter to feed a local oscillation to the CRM and the CTM with a tunable power ratio. The monolithic transceiver provides tunable responsivity by employing photodiodes for opto-electrical conversion. The monolithic transceiver also employs a polarization beam rotator-splitter (PBRS) and a polarization beam rotator-combiner (PBRC) for supporting modulation schemes including polarization multiplexed quadrature amplitude modulation (PM-QAM) and polarization multiplexed quadrature phase shift keying (PM-QPSK).

An apparatus for intraoral imaging has an illumination source that directs light to an object. An imaging apparatus forms an image at an image sensor array from reflected light from the object, the imaging apparatus having an optical stop along an optical axis. A phase modulator is disposed at or near the optical stop. An image processor conditions data from the image sensor array and provides processed image data of the object.

A system and method for applying a time-varying phase shift to an optical signal is described. Such a phase shift results in a frequency shift of the optical signal, which can be useful for instance in sensing applications. The design uses cross phase modulation (XPM) in a nonlinear medium such as optical fiber. The pump producing the XPM experiences a change in energy along the medium, for instance due to loss. The pump and signal have mismatched group velocities such that they walk-off each other in time, and the pump pulse repetition rate is chosen so that it has a specific relationship with respect to the walk-off. The design is compatible with very low signal loss and does not require high fidelity electrical control signals. It is capable of high-efficiency one-directional serrodyne frequency shifts, as well as producing symmetric frequency shifts. It can also be made polarization independent.

A thin-film device for a wavelength-tunable semiconductor laser. The device includes a cavity between a high-reflectivity facet and an anti-reflection facet designed to emit a laser light of a wavelength in a tunable range determined by two Vernier-ring resonators with a joint-free-spectral-range between a first wavelength and a second wavelength. The device further includes a film including multiple pairs of a first layer and a second layer sequentially stacking to an outer side of the high-reflectivity facet. Each layer in each pair has one unit of respective optical thickness except one first or second layer in one pair having a larger optical thickness. The film is configured to produce inner reflectivity of the laser light from the high-reflectivity facet at least >90% for wavelengths in the tunable range starting from the first wavelength but at least <50% for wavelengths in a 25 nm range around the second wavelength.

An adiabatic coupling phase modulation module has an optical substrate, an asymmetric adiabatic coupling polarization beam splitter and two electro-optical phase modulators. The asymmetric adiabatic coupling polarization beam splitter performs band spatial filtering on a quantum light source signal to output a light source signal of a specific wavelength band, and performs polarization spatial filtering on the light source signal of specific wavelength band to output a first orthogonal polarization direction light source signal of the specific wavelength band and a second orthogonal polarization direction light source signal of the specific wavelength band. The two electro-optical phase modulators respectively perform phase coding processes on the first orthogonal polarization direction light source signal and the second orthogonal polarization direction light source signal.

An optical resonator frequency comb (1) comprising a main optical resonator (2) being made of a resonator material, which has a third order nonlinearity and an anomalous resonator dispersion; a continuous wave (cw) laser (4) configured for supplying continuous laser light into an optical waveguide (5), which is coupled with the main optical resonator. The cw laser (4), the optical waveguide (5) and the main optical resonator (2) are arranged for resonantly coupling the cw laser light into the main optical resonator (2) for forming a single dissipative soliton circulating in the main optical resonator (2) corresponding to the generation of a frequency comb. Furthermore, the optical resonator frequency comb further comprises an auxiliary optical element (3, 25, 26) configured to induce a phase shift to a frequency comb component at the cw laser frequency to enhance the conversion efficiency of a generated frequency comb. The disclosure also relates to an associated method.

A reflective spatial light modulator (SLM) made of an electro-optic material in a one-sided Fabry-Perot resonator can provide phase and/or amplitude modulation with fine spatial resolution at speeds over a Gigahertz. The light is confined laterally within the electro-optic material/resonator layer stack with microlenses, index perturbations, or by patterning the layer stack into a two-dimensional (2D) array of vertically oriented micropillars. Alternatively, a photonic crystal guided mode resonator can vertically and laterally confine the resonant mode. In phase-only modulation mode, each SLM pixel can produce a π phase shift under a bias voltage below 10 V, while maintaining nearly constant reflection amplitude. This high-speed SLM can be used in a wide range of new applications, from fully tunable metasurfaces to optical computing accelerators, high-speed interconnects, true 2D phased array beam steering, beam forming, or quantum computing with cold atom arrays.

A method for fabricating a liquid crystal phase modulation device is provided. The method includes detecting thicknesses of a plurality of portions of a reference liquid crystal layer of a reference liquid crystal phase modulation sample; determining a distribution according to the thicknesses of the portions of the reference liquid crystal layer; forming a plurality of spacers over a first substrate in the determined distribution; and combining the first substrate with a second substrate and a liquid crystal layer to form the liquid crystal phase modulation device.

An interference imaging device includes a light interference generator that includes: a light wave splitter configured to reflect a part of incident light and to allow a remaining part of the incident light to pass through; a phase modulator configured to modulate a phase of incident light that has passed through the light wave splitter; and a reflector configured to reflect the phase-modulated incident light from the phase modulator so that the reflected, phase-modulated incident light overlaps with incident light that has been reflected by the light wave splitter.

A semiconductor structure includes, an optical component and a thermal control mechanism. The optical component includes a first main path that splits into a first side path and a second side path so that the first side path and the second side path are separated from one another. The thermal control mechanism configured to control a temperature of both the first side path and the second side path, wherein the first thermal control mechanism includes a first thermoelectric member and a second thermoelectric member that are positioned between the first side path and the second side path and the first thermoelectric member and the second thermoelectric member have opposite conductive types.