A laser device for use with a display including a plurality of pixels is disclosed. The laser device includes a gain section and a modulator. The gain section is electrically coupled with a first current or voltage source. The gain section is configured to selectively amplify an optical power of light reflecting within the gain section based on a first drive current or voltage supplied from the first current or voltage source to the gain section. The modulator is optically coupled with the gain section. The modulator is electrically coupled with a second current or voltage source. The modulator is configured to selectively attenuate or amplify an optical power of light received from the gain section based on a second drive current or voltage supplied from the second current or voltage source to the modulator. Light emitted from the modulator is provided to the display.

A synthesizer includes a first resonator mirror, a second resonator mirror, and a gain medium disposed within a laser resonator cavity defined by the first resonator mirror and the second resonator mirror. The synthesizer includes a saturable absorber operationally coupled to the gain medium and having active control such that the saturable absorber is configured to generate a waveform via an injection locking signal to create a mode locking effect, the waveform having a frequency comb defined by dimensions of the gain medium. The synthesizer also includes a crystal electro-optical modulator disposed within the laser resonator cavity. The waveform passes through the modulator to impinge on a photodiode to output an emission RF waveform. Changing the voltage applied to the modulator changes the index of refraction of the modulator, altering an optical path length of the laser resonator cavity to adjust a frequency of the emission RF waveform.

A photonic integrated circuit device includes a lasing cavity for resonating at a plurality of discrete wavelengths and an optical feedback cavity operably coupled to the lasing cavity via a front surface of the lasing cavity. The optical feedback cavity has a reflective element for reflecting light, at least partially, back into the lasing cavity to form a resonant Fabry-Perot cavity between the front surface and the reflective element. The optical feedback cavity includes a variable phase shifting element adapted for receiving an input signal to control a phase shift of light propagating in the optical feedback cavity. The amount of light entering the lasing cavity from the optical feedback cavity is low enough to avoid dynamic instability of the lasing cavity. The reduction in light is obtained using an attenuator.

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.

An inspection method for inspecting a semiconductor laser device integrated with a semiconductor laser, an electroabsorption modulator for input the output of the semiconductor laser, and a photodetector for detecting intensity of part of the laser light output from the semiconductor laser includes a step of acquiring a transverse-mode light output characteristic that is a relationship between an injection current to the semiconductor laser and the output of the photodetector; a step of applying a reverse bias voltage to the electroabsorption modulator and acquiring a total light output characteristic that is a relationship between the injection current to the semiconductor laser and a photocurrent output from the electroabsorption modulator; and a step of comparing the total light output characteristic with the transverse-mode light output characteristic, thereby to determine whether or not the semiconductor laser device under inspection is abnormal in the transverse mode.

The present disclosure is generally directed to an EML with a filter layer disposed between an active region of the EML and a substrate of the EML to absorb a portion of unmodulated light energy, and preferably the unmodulated light energy caused by transverse electric (TE) substrate mode. The filter layer preferably comprises a material with an energy band gap (Eg) that is less than the energy band gap of the predetermined channel wavelength to absorb unmodulated laser light.

A laser device includes a laser and a controller. The laser has an optical cavity that includes an active gain section and a phase shifter. The controller is configured to excite the active gain section to lase light out of the optical cavity. The controller is further configured to, while the light is being lased out of the optical cavity, modulate a refractive index of the phase shifter to shift an optical phase of lasing modes of the lased light to thereby reduce coherence of the lased light.

A photonic integrated circuit including first and second opto-electronic devices that are fabricated on a semiconductor wafer having an epitaxial layer stack including an n-type indium phosphide-based contact layer that is provided with at least one selectively p-type doped tubular-shaped region for providing an electrical barrier between respective n-type contact regions of the first and second opto-electronic devices that are optically interconnected by a passive optical waveguide that is fabricated in a non-intentionally doped waveguide layer including indium gallium arsenide phosphide, the non-intentionally doped waveguide layer being arranged on top of the n-type contact layer, wherein a first portion of the at least one selectively p-type doped tubular-shaped region is arranged underneath the passive optical waveguide between the first and second opto-electronic devices. An opto-electronic system including the photonic integrated circuit.

A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the optical resonator has a multi-section structure separated into at least one gain region and at least one absorption region, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

A first current injection unit that injects a DBR current into a rear DBR region and a front DBR region and a second current injection unit that injects a phase adjustment current into a phase adjustment region are included. The second current injection unit injects the phase adjustment current that changes at a frequency that is twice as much as that of the DBR current into the phase adjustment region in synchronization with the DBR current. The first current injection unit inverts the DBR current to a positive value in a region in which the DBR current is a negative value.