An electroabsorption modulated laser having a first face, a second face, an optical cavity and an active region, the optical cavity being defined by a semiconductor substrate and having a length extending between the first face and the second face, and the active region being configured for injection of charge into the cavity and having effective bandgap energies at respective distances along the length of the cavity, the electroabsorption modulated laser comprising a first modulator section extending between a first position and a second position and comprising a first part of the active region, and a second modulator section extending between the second position and a third position and comprising a second part of the active region, wherein the bandgap energy of the first part of the active region adjacent the first position is higher than the bandgap energy adjacent the second position.

An electroabsorption modulated laser having a first face, a second face, an optical cavity and an active region, the optical cavity being defined by a semiconductor substrate and having a length extending between the first face and the second face, and the active region being configured for injection of charge into the cavity and having effective bandgap energies at respective distances along the length of the cavity, the electroabsorption modulated laser comprising a first modulator section extending between a first position and a second position and comprising a first part of the active region, and a second modulator section extending between the second position and a third position and comprising a second part of the active region, wherein the bandgap energy of the first part of the active region adjacent the first position is higher than the bandgap energy adjacent the second position.

A semiconductor optical element includes a first cladding layer; a second cladding layer formed in a ridge shape; and optical confinement layer interposed between the first cladding layer and the second cladding layer to propagate light, wherein the second cladding layer is configured with a ridge bottom layer; a ridge intermediate layer; and a ridge top layer in this order from the optical confinement layer, and the ridge intermediate layer is formed wider in cross section perpendicular to the optical axis—the light propagating direction in optical confinement layer—than the ridge bottom layer and the ridge top layer.

There is provided a method of operating a laser. The method comprises receiving a target power and calculating an operating power of a lasing module of the laser. The operating power may be calculated based on the target power and a minimum lasing power of the lasing module. The method also comprises determining an operating current for the lasing module based on the operating power, and driving the lasing module at the operating current to produce an output light having the operating power. In addition, the method comprises providing the output light to an optical modulator of the laser, and operating the optical modulator to modulate the output light to have an output power corresponding to the target power.

A novel, monolithically integrated mid-IR optical phased array (OPA) structure which eliminates the wafer bonding process to achieve highly efficient surface emitting optical beam steering in two dimensions is disclosed. Since solar energy is about 15-20 times smaller than that at 1.55 um, mid-IR is more favorable for the atmospheric transmission due to lower solar radiance backgrounds. For the beam steering, thermo-optic phase shifting is used for azimuthal plane beam steering and laser wavelength tuning is used for elevation plane beam steering. The OPA structure disclosed comprises a wavelength- tunable a QCL, a 1×32 splitter, thermo-optic phase-shifters, and sub-wavelength grating emitters. The disclosed OPA provides a low-cost, low-loss, low-power consumption, robust, small footprint, apparatus that may be used with expendable UAV swarms. A LiDAR may be created by monolithically integrating a QCD with the apparatus. Other embodiments are described and claimed.

An on-chip integrated semiconductor laser structure and a method for preparing the same. The structure includes: an epitaxial structure including a first N contact layer, a first N confinement layer, a first active region, a first P confinement layer, a first P contact layer, an isolation layer, a second N contact layer, a second N confinement layer, a second active region, a second P confinement layer, and a second P contact layer sequentially deposited on a substrate; a first waveguide and a second waveguide; a first optical grating and a second optical grating; and current injection windows.

In the present disclosure, in an EADFB laser in which an SOA has been integrated, a new configuration in which a problem of deterioration of optical waveform quality and insufficient optical output is solved or mitigated while taking advantage of characteristics that the same layer structure can be used and a manufacturing process can be simplified is shown. In an optical transmitter of the present disclosure, a waveguide structure having different core widths (waveguide widths) is adopted while using the same layer structure for a DFB laser and the SOA. Waveguides with different core widths are adopted so that a problem of insufficient saturated optical output or waveform deterioration due to a pattern effect is solved and mitigated. A passive waveguide region having a tapered shape is introduced in a part between an EA modulator and the SOA so that a waveguide width is continuously changed.

In the present disclosure, in an EADFB laser in which an SOA has been integrated, a new configuration in which a problem of deterioration of optical waveform quality and insufficient optical output is solved or mitigated while taking advantage of characteristics that the same layer structure can be used and a manufacturing process can be simplified is shown. In an optical transmitter of the present disclosure, a waveguide structure having different core widths (waveguide widths) is adopted while using the same layer structure for a DFB laser and the SOA. Waveguides with different core widths are adopted so that a problem of insufficient saturated optical output or waveform deterioration due to a pattern effect is solved and mitigated. A passive waveguide region having a tapered shape is introduced in a part between an EA modulator and the SOA so that a waveguide width is continuously changed.

In some implementations, an optical device (e.g., a monolithic master oscillator power amplifier (MOPA) diode) may include a first facet, one or more gratings, an amplifier structure terminated with a second facet, and an oscillator array that includes multiple singlemode oscillators coupled to the first facet and to the one or more gratings. In some implementations, the multiple singlemode oscillators may be configured to generate multiple seed beams and to transmit the multiple seed beams into the amplifier structure through the one or more gratings.

In some implementations, an optical device (e.g., a monolithic master oscillator power amplifier (MOPA) diode) may include a first facet, one or more gratings, an amplifier structure terminated with a second facet, and an oscillator array that includes multiple singlemode oscillators coupled to the first facet and to the one or more gratings. In some implementations, the multiple singlemode oscillators may be configured to generate multiple seed beams and to transmit the multiple seed beams into the amplifier structure through the one or more gratings.