A photonic chip. In some embodiments, the photonic chip includes a waveguide; and an optically active device comprising a portion of the waveguide. The waveguide may have a first end at a first edge of the photonic chip; and a second end, and the waveguide may have, everywhere between the first end and the second end, a rate of change of curvature having a magnitude not exceeding 2,000/mm.sup.2.

An optical transmitter includes: a set of reflective silicon optical amplifiers (RSOAs), a set of ring modulators, a shared broadband reflector, a set of intermediate waveguides, and a shared waveguide. Each intermediate waveguide channels light from an RSOA in proximity to an associated ring modulator to cause optically coupled light to circulate in the associated ring modulator. The shared waveguide is coupled to the shared broadband reflector, and passes in proximity to the set of ring modulators, so that light circulating in each ring modulator causes optically coupled light to flow in the shared optical waveguide. During operation, each RSOA forms a lasing cavity with the shared broadband reflector, wherein each lasing cavity has a different wavelength, which is determined by a resonance of the associated ring modulator. The different wavelengths are combined in the shared waveguide to produce a combined output.

The present invention provides an optical modulator, which can be reduced in size with size reduction of an optical waveguide and electric wiring as compared to a conventional optical modulator. An optical modulator according to an embodiment includes a substrate; an optical waveguide provided on the substrate and configured to guide light; a modulation unit formed of part of the optical waveguide and configured to modulate the light; and electric wires provided on the substrate and configured to supply a high-frequency electric signal to the modulation unit. One end portion and another end portion of the optical waveguide are provided on a first end surface, one end portion of the electric wiring is provided along the first end surface, another end portion of the electric wiring is provided along a second end surface being different from the first end surface.

An optical transmitter includes a reflective semiconductor optical amplifier (RSOA) coupled to an input end of a first optical waveguide. An end of the first optical waveguide provides a transmitter output for the optical transmitter. Moreover, a section of the first optical waveguide between the input end and the output end is optically coupled to a ring modulator that modulates an optical signal based on an electrical input signal. A passive ring filter (or a 1N silicon-photonic switch and a bank of band reflectors) is connected to provide a mirror that reflects light received from the second optical waveguide back toward the RSOA to form a lasing cavity. Moreover, the ring modulator and the passive ring filter have different sizes, which causes a Vernier effect that provides a large wavelength tuning range for the lasing cavity in response to tuning the ring modulator and the passive ring filter.

In the Waveguide Array Modulator (WAM) a single electrical signal drives an array of waveguide optical modulators, creating multiple modulated output signals that can be combined to provide a higher output power than from a single waveguide based modulator, enabling a higher dynamic range system. Alternatively, using a WAM in which different waveguide optical modulators are designed for different dynamic ranges, e.g. one highly efficient modulator for low level signals and one low efficiency but linear modulator for high level signals, the WAM based system can provide a higher dynamic range than from a single waveguide based modulator. Various WAM based systems for different applications are included.

A dual-ring-modulated laser includes a gain medium having a reflective end coupled to a gain-medium reflector and an output end coupled to a reflector circuit to form a lasing cavity. This reflector circuit comprises: a first ring modulator; a second ring modulator; and a shared waveguide that optically couples the first and second ring modulators. The first and second ring modulators have resonance peaks, which are tuned to have an alignment separation from each other. During operation, the first and second ring modulators are driven in opposing directions based on the same electrical input signal, so the resonance peaks of the first and second ring modulators shift wavelengths in the opposing directions during modulation. The modulation shift for each of the resonance peaks equals the alignment separation, so the resonance peaks interchange positions during modulation to cancel out reflectivity changes in the lasing cavity caused by the modulation.

A system is disclosed for producing an output photon having a predefined frequency. The system comprises a frequency comb generator for generating a frequency comb. The system further comprises a frequency comb mode selector configured to: receive a heralding signal representative of the detection of a first photon of a frequency-correlated photon pair, the heralding signal indicative of a frequency of the heralded second photon of the frequency-correlated photon pair; and select, based on the received heralding signal, a comb spectral mode of the frequency comb. The system further comprises a non-linear photonic element configured to receive the heralded second photon and the selected comb spectral mode and produce an output photon having the predefined frequency based on the frequency of the heralded second photon and the selected comb spectral mode. Methods, controllers and computer-readable media are also described herein.

A photonic chip includes:a waveguide layer;one or two Mach-Zehnder modulators formed on and/or in the waveguide layer, comprising a first branch and a second branch, the branches being arranged between an optical input and an optical output in such a way that a light ray injected at the optical input is divided into a first ray and a second ray, which are then recombined at the optical output, each modulation branch being configured to modulate the phase of a light ray. The photonic chip further comprises at least two semiconductor optical amplifiers that are arranged so as to separately amplify the first ray and the second ray before they are recombined at the optical output.

Systems and methods which provide for the generation of optical frequency combs using a microring resonator optical frequency comb generator configuration are described. A microring resonator optical frequency comb generator configuration of embodiments comprises a plurality of fiber loop laser cavities and at least one microring cavity are utilized. For example, an optical frequency comb generator may include a first fiber loop laser cavity, a second fiber loop laser cavity that is symmetrical with the first fiber loop laser cavity, and a microring resonator that is coupled into both of the first and second fiber loop laser cavities. The microring resonator may be configured to provide a high quality factor, Q, value. The microring resonator of embodiments works together with optical bandpass filters and amplifiers in the multiple fiber loops to make the generated optical frequency comb stable and flexible.

Beam steering devices and optical apparatuses including the beam steering devices are provided. A beam steering device includes a light source configured to generate input lights having first different wavelengths, a multiplexer configured to simultaneously receive the generated input lights, and multiplex the received input lights into a multiplexed light, and an optical splitter configured to split the multiplexed light. The beam steering device further includes an optical modulator configured to modulate the split light, and an emitter configured to simultaneously emit output lights having second different wavelengths to different points arranged in a first direction, based on the modulated light.