Abstract: To detect deterioration of an SOA and perform feedback control to keep light intensity of output light constant in a configuration in which a DFB laser, an EA modulator, and the SOA are monolithically integrated. A semiconductor optical integrated element includes: a DFB laser that outputs continuous light; an EA modulator that modulates the continuous light; a first multimode interference coupler that inputs the modulated light from a first input port, divides the modulated light, and outputs the divided modulated light from two or more output ports; semiconductor optical amplifiers that are connected to respective output ports of the first multimode interference coupler and amplify each of the divided modulated light; a second multimode interference coupler that has input ports connected to respective outputs of the semiconductor optical amplifiers, multiplexes the amplified modulated light, and outputs the multiplexed modulated light from a first output port; and a monitoring waveguide.

Abstract: A semiconductor Mach-Zehnder optical modulator includes input side lead-out lines, phase modulation electrode lines, output side lead-out lines, electrodes that apply modulation signals propagating through the phase modulation electrode lines to respective waveguides, and ground lines. Furthermore, at least one n-type semiconductor layer or p-type semiconductor layer is formed between a substrate and a dielectric layer in a lower layer under the output side lead-out lines intermittently along the output side lead-out lines.

Abstract: An optical transmitter that multiplexes and outputs a plurality of wavelength channels includes: a first light source; at least one second light source having a different wavelength from the first light source, the at least one second light source each having a different wavelength; an optical multiplexer that causes an output light beam from the first light source to be transmitted from a first end surface to a second end surface facing the first end surface, causes the output light beam from the first light source to be reflected by a reflecting mirror formed on the second end surface, causes an output light beam from the second light source to pass through a wavelength filter formed on the first end surface, causes the optical light beam from the second light source to be reflected by the reflecting mirror, and causes output light beams of the respective wavelength channels to reciprocate between the reflecting mirror and the wavelength filter, to sequentially multiplex the output light beams of the respec

Abstract: In a DBR laser of a wavelength-tunable transmitter, a rear DBR region, an active region, and a front DBR region are integrated along an optical axis direction. The diffraction grating structure is set so that an oscillation mode using a reflection peak on the shortest wavelength side among a plurality of reflection peaks corresponding to the wavelength-tunable band is easily oscillated the most in a state where a current to the two DBR regions of the SSG-BPFR is 0. The SSG-DBR laser is configured such that the average period value of the diffraction grating of the front DBR is larger than the average period value of the diffraction grating of the rear DBR. The diffraction grating is configured so that the wavelengths of the reflection peaks on the shortest wavelength side among the plurality of reflection peaks coincide with each other between the two DBR regions in a state where no current is supplied.

Abstract: The optical loss of the output light of the first light source transmitted through the optical multiplexer is suppressed. An optical transmitter includes: a first light source; one or more second light sources having mutually different wavelengths and each having a wavelength different from that of the first light source; an optical multiplexer that transmits output light from the first light source from a first end surface to a second end surface facing the first end surface, causes the output light to reflect on a reflecting mirror formed on the second end surface, transmits output light from the second light source through a wavelength filter formed on the first end surface, causes the output light to reflect on the reflecting mirror, and multiplexes the output light; and a first monitor PD for monitoring optical power with a part of the output light from the first light source.

Abstract: A semiconductor structure includes InP as a substrate and includes, in order, a multi-quantum well, an anti-diffusion layer, and a p-type InP layer doped with Zn. The anti-diffusion layer includes a plurality of layers that substantially lattice-match InP, and at least one layer among the plurality of layers contains Al, In, and As and is doped with carbon.

Abstract: An optical transmitter of the present disclosure is obtained by integrating a DFB laser, an EA modulator, and SOAs, and intensity-modulated light from the EA modulator is optically amplified in the parallelized SOAs. The parallelized SOAs include a first MMI that splits the intensity-modulated light from the EA modulator toward two or more optical paths, corresponding SOAs that optically amplify the split light, and a second MMI that combines the optically amplified lights. The components of the optical transmitter are integrated on a single substrate. In the parallelized SOAs, it is possible to obtain a higher output power and an improved waveform quality, by applying a total SOA injection current that is the same as that of an optical transmitter of a conventional technology including a single SOA.

Abstract: A highly efficient optical burst transmitter is provided. An embodiment is an optical burst transmitter including a control circuit configured to output a data signal and a burst control signal and a semiconductor optical amplifier configured to output an optical data signal modulated using the data signal as an optical burst data signal controlled using the burst control signal, the optical burst transmitter including: an electric line configured to connect the control circuit and the semiconductor optical amplifier and transmit the burst control signal; and an impedance matching circuit configured to impedance-match a characteristic impedance of the electric line and the semiconductor optical amplifier with each other.

Abstract: There is provided a highly convenient package for an optical module in which a device can be mounted as it is even when the number and mounting position thereof are different according to the device to be mounted. The package includes a base plate having a top surface on which devices are assembled, an optical fiber mounting component mounted on the top surface of the base plate, a direct current electrical interface component and a high frequency electrical interface component mounted on the top surface of the base plate. The optical fiber mounting component and the electrical interface components are separately manufactured, separately assembled on the top surface of the base plate, and fixed in different modes. The optical fiber mounting component is fixed by fastening with screws and fixed by soldering, and the electrical interface components are fixed by fastening with the screw.

Abstract: Provided is a semiconductor chip that can reduce the man-hours for mounting on an optical module, a subcarrier, or the like, and reducing the dedicated area of the subcarrier or the like. The semiconductor chip includes a waveguide that is terminated inside at an output end portion from which light is emitted, without contacting an emission end face, and a window region made of a bulk semiconductor and disposed between the waveguide and the emission end face, wherein the semiconductor chip is provided with an open groove formed in the output end portion so that the emission end face is a side wall formed by etching.

Abstract: An optical signal transmitter (AXEL) in which a quality of an optical signal waveform is maintained includes a distributed Bragg reflector to be coupled with an emission end surface of an SOA in an optical circuit unit including an optical waveguide core portion formed on an upper surface of a substrate. In the optical circuit unit, a diffraction grating formed on an upper surface side opposite to an absorption layer of an EA optical modulator and a diffraction grating formed on an upper surface side of a reflection layer of the distributed Bragg reflector have a wavelength selectivity.

Abstract: This semiconductor wafer has formed therein a plurality of chips, each of which has incorporated therein a semiconductor element to be tested. The semiconductor wafer is characterized by comprising: first pads which are formed on the chips, and to which a plurality of probe needles are connected, the probe needles being connected to the semiconductor elements and used for testing the semiconductor elements; and a second pad that is used for performing a contact check on the probe needles, the second pad having a conductive section greater in length than the distance between the centers of the first pads.

Abstract: An optical semiconductor chip of the present disclosure includes a high frequency line between an electrode pad receiving a modulation signal and a modulation electrode on the optical waveguide having a light absorption layer. The depletion layer capacitance generated in the light absorption layer is canceled by an inductor component of the high frequency line. When a portion directly below the high frequency line is embedded with a low-dielectric-constant material or is made hollow, the parasitic capacitance is further reduced. The high frequency line may have a zigzag shape as well as a linear shape. The electrode pad on the optical semiconductor chip can be connected to other substrates including RF lines for modulation signal input by bumps or wire bonding.

Abstract: In the present disclosure, in an EADFB laser in which an SOA has been integrated, a new configuration in which deterioration of optical waveform quality is solved or mitigated while keeping characteristics that a manufacturing process can be simplified by using the same layer structure is indicated. In the optical transmitter of the present disclosure, a waveguide structure having a tapered structure in at least a part of the SOA waveguide is adopted. A width of the waveguide is changed to be reduced in an SOA region, and an amount of carrier consumption is made uniform in an optical waveguide direction. A waveguide width is continuously reduced in an optical waveguide direction in the SOA so that the optical confinement coefficient is reduced, and light power distributed in an active layer region is made constant.

Abstract: 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.

Abstract: In an EADFB laser with an integrated SOA, a new configuration in which deterioration of optical waveform quality is solved or mitigated while taking advantage of characteristics that the same layer structure can be used and the manufacturing process can be simplified is shown. In an optical transmitter of the present disclosure, a carrier density is optimized depending on a light intensity inside the SOA and an amount of carrier consumption. The SOA is electrically separated into a plurality of regions, and a current is injected into each region independently. The divided SOA region is configured so that a length of the SOA region becomes shorter as a region is farther from an incidence end of the SOA. Further, for the divided SOA, an amount of carrier consumption increases as the SOA region is farther from the incidence end, so that a current injection amount is increased.

Abstract: There is provided a highly convenient package for an optical module in which a device can be mounted as it is even when the number and mounting position thereof are different according to the device to be mounted. The package includes a base plate having a top surface on which devices are assembled, an optical fiber mounting component mounted on the top surface of the base plate, a direct current electrical interface component and a high frequency electrical interface component mounted on the top surface of the base plate. The optical fiber mounting component and the electrical interface components are separately manufactured, separately assembled on the top surface of the base plate, and fixed in different modes. The optical fiber mounting component is fixed by fastening with screws and fixed by soldering, and the electrical interface components are fixed by fastening with the screws.

Abstract: Reflection between a Mach-Zehnder modulator and a termination resistor is suppressed. An optical modulator includes a differential drive open collector driver IC, a differential drive semiconductor Mach-Zehnder modulator, and a differential terminator. The Mach-Zehnder modulator includes waveguides and a differential high-frequency line. The differential terminator includes a differential high-frequency line and termination resistors. The differential high-frequency line includes a capacity provided at least one of between signal lines and between a signal line and a ground line.

Abstract: There is provided an optical element mounted on a substrate and an optical coupling element mounted on the substrate. The optical coupling element includes a guide unit extending in a direction parallel to a plane of the substrate so as to fix an optical fiber. There is provided a mold resin layer formed on the substrate so as to cover the optical element and expose a side surface of the optical coupling element at one end of the guide unit. The optical element includes a light incidence/emission unit on a side surface perpendicular to the plane of the substrate, and the other end of the guide unit and the light incidence/emission unit are disposed to face each other.

Abstract: Provided is a semiconductor light source element or an optical device including a semiconductor optical waveguide of a high-mesa semi-insulated embedded structure having a window structure made of the same material as an overclad layer at a light emission end, and a method for manufacturing thereof, in which an active layer at a portion of the window structure is removed, and then the same layer as the overclad layer is formed.