A semiconductor laser comprising a single mode laser cavity having a stack of semiconducting layers defining a transversal p-n junction is provided. A plurality of electrodes are coupled to corresponding sections of the laser cavity along the longitudinal light propagation direction, each corresponding section defining one of an amplification section or a modulation section. One or more DC sources are coupled to the electrodes associated with the amplification sections to forward-bias the p-n junction above transparency, so as to provide gain in the associated amplification sections. One or more modulation signal sources are coupled to the electrodes associated with the modulation sections, and apply a modulation signal across the p-n junction below transparency, the modulation signal providing a modulation of an output optical frequency of the semiconductor laser. Each modulation section is operated in photovoltaic mode.

A disclosed laser device includes a laser diode configured to output laser light with a variable pulse pattern, a pre-amp optical unit configured to amplify the laser light output from the laser diode to a first energy level and includes a plurality of Pockels cells and a first amplifier, a second amplifier configured to amplify the laser light amplified to the first energy level to a second energy level, a third amplifier configured to amplify the laser light amplified to the second energy level to a third energy level, and a control unit configured to set a pulse pattern of the laser light output from the laser diode and control a driver of the laser diode, the first amplifier, the second amplifier, and the third amplifier based on the pulse pattern.

An emitting device is intended for delivering photons with a chosen wavelength. This emitting device includes an InP substrate with a directly modulated laser arranged for generating photons modulated by a non-return-to-zero modulation to produce data to be transmitted, a passive ring resonator monolithically integrated with the directly modulated laser and having a resonance amongst several ones that is used for filtering a zero level induced by the data modulation, and a tuning means arranged along the directly modulated laser and/or around the ring resonator to tune the photon wavelength and/or the ring resonator resonance used for filtering.

A semiconductor optical device includes: a first conductive type semiconductor layer; an active layer; a second conductive type semiconductor layer including a ridge portion; a pair of first grooves, formed on bottom surfaces of both sides of the ridge portion and dividing the active layer; an optical functioning part including the first and second conductive type semiconductor layers, converting a state of light, and having a height higher than a height of the bottom surface of the ridge portion; and a second groove, at least a part thereof being formed on the optical functioning part, an end portion thereof being connected to the first groove, the second conductive type semiconductor layer being divided, and the maximum height of an inner wall surface thereof being higher than the maximum height of an inner wall surface of the first groove.

A spot-size converter includes first and second waveguide structures. The first waveguide structure extends longitudinally along a waveguide axis from a first end to a second end and is configured to support a first optical mode at the first end. The second waveguide structure is formed within the first waveguide structure. The second waveguide structure extends longitudinally between the first end and the second end. The second waveguide structure is configured to support a second optical mode at the second end. The second optical mode has a different diameter than the first optical mode. The second waveguide structure includes a waveguide core that has a first cross-sectional area in a first plane normal to the waveguide axis at the first end and a second cross-sectional area in a second plane normal to the waveguide axis at the second end. The second cross-sectional area is larger than the first cross-sectional area.

The present invention provide a laser, where the laser is divided into a laser region and a grating adjustment region through a first electrical isolation layer; the laser region is configured to generate optical signals, where the optical signals include an optical signal with a wavelength corresponding to a 0 signal and an optical signal with a wavelength corresponding to a 1 signal; the grating adjustment region is configured to adjust a wavelength of the grating adjustment region by controlling current of the grating adjustment region, so that the optical signal with the wavelength corresponding to the 1 signal of the laser region passes through the grating adjustment region, and the optical signal with the wavelength corresponding to the 0 signal of the laser region returns to the laser region, thereby implementing suppression to chirp of a directly modulated laser.

An emitting device (1) is intended for delivering photons with a chosen wavelength. This emitting device (1) comprises an InP substrate (2) with a directly modulated laser (3) arranged for generating photons modulated by a non-return-to-zero modulation to produce data to be transmitted, a passive ring resonator (4) monolithically integrated with the directly modulated laser (3) and having a resonance amongst several ones that is used for filtering a zero level induced by the data modulation, and a tuning means (5) arranged along the directly modulated laser (3) and/or around the ring resonator (4) to tune the photon wavelength and/or the ring resonator resonance used for filtering.

A method of making an optical modulator by determining the material composition of the quantum well region in the waveguide portion of the modulator so that the modulator is transparent at a gain peak wavelength that is greater than the predetermined wavelength by a predetermined amount, and fabricating the modulator with the determined material composition.

A semiconductor device comprising a substrate; a monolithic gain region disposed on the substrate and operable to produce optical gain in response to current injection, including a first electrode over a first portion of the gain region having a first length L.sub.1, with a first current I.sub.1 being applied; and a second electrode over a second portion of the gain region having a second length L.sub.2, with a second current I.sub.2 being applied; wherein I.sub.1/L.sub.1 is greater than I.sub.2/L.sub.2.

A synthesizer including a controller configured to receive a first signal. A digital-to-analog converter (DAC) is coupled to the controller and is configured to generate a voltage bias based on the first signal. The voltage bias corresponds to a target resonant frequency. A semiconductor laser is coupled to the DAC and is configured to receive a second signal tone. The semiconductor laser generates a plurality of tone signals having octave multiples of a base sub-harmonic tone of the second signal tone.