Provided is a tunable laser that prevents basic characteristics of the laser from deteriorating and enables a high-speed control of the oscillation wavelength. The tunable laser includes a semiconductor gain portion including a III-V compound semiconductor, an optical feedback portion configured to diffract light generated in the semiconductor gain portion and feed the diffracted light back to the semiconductor gain portion, and an optical modulation portion including an optical waveguide that contains doped indirect transition-type silicon. The semiconductor gain portion and the optical modulation portion are disposed so that optical modes thereof overlap each other, and the semiconductor gain portion includes an embedded active layer thin film of a type in which a current is injected in a lateral direction.

A light emitter device (100) comprises a substrate (10) and a photonic crystal (20), which is arranged on the substrate (10) and comprises pillar- and/or wall-shaped semiconductor elements (21), which are arranged periodically standing out from the substrate (10), wherein the photonic crystal (20) forms a resonator, in which the semiconductor elements (21) are arranged in a first resonator section (22) with a first period (d.sub.1), in a second resonator section (23) with a second period (d.sub.2) and in a third resonator section (24) with a third period (d.sub.3), wherein on the substrate (10) the second resonator section (23) and the third resonator section (24) are arranged on two mutually opposing sides of the first resonator section (22) and the second period (d.sub.2) and the third period (d.sub.3) differ from the first period (d1), the first resonator section (22) forms a light-emitting medium and the third resonator section (24) forms a coupling-out region, through which a part of the light field in the first resonator section (22) can be coupled out of the resonator in a light outcoupling direction parallel to a substrate surface (11) of the substrate (10). Methods for operating and producing the light emitter device (100) are also described.

A laser assembly (1) comprising: a semiconductor laser (2) with a fast gain medium, wherein the gain relaxation time of the gain medium is smaller than the round-trip time in the standing wave cavity, in particular a quantum cascade laser or an interband cascade laser, and a standing wave cavity (3); a DC source (9) coupled to the standing wave cavity (3) for pumping the laser (2); and an AC injection device (10) for injecting an electrical AC signal into the standing wave cavity (3) to stabilize an optical frequency comb, the AC injection device being suitable for producing an electrical AC signal within a range and/or within an integer multiple of the range, wherein the range is within ±1% of the natural round-trip frequency in the standing wave cavity, comprising at least a first and a second electric contact section (5, 6) extending along a first longitudinal side of the longitudinal extension of the standing wave cavity (3), wherein the AC injection device (10) is coupled to the first and/or to the second electric contact section (5, 6) such that the complex amplitude of the injected electrical AC signal differs for the first and the second longitudinal electric contact section (5, 6).

According to an aspect, an optical system includes a laser diode configured to emit optical signals and at least two size-switchable broken racetrack ring resonators optically coupled to an optical waveguide, where each broken racetrack ring resonator is configured to exhibit a resonant wavelength. The optical system also includes a tuning arrangement associated with the broken racetrack ring resonators, where the tuning arrangement includes a micro electro-mechanical system (MEMS) or nano electro-mechanical system (NEMS) actuator mechanically coupled to a first portion of a first one of the broken racetrack ring resonators and configured to mechanically move the first portion so as to change the resonant wavelength of the first one of the broken racetrack ring resonators.

A method (700) of biasing a tunable laser (310) during burst-on and burst-off states includes receiving a burst mode signal (514) indicative of the burst-on state or the burst-off state and when the burst mode signal is indicative of the burst-on state: delivering a first bias current (I.sub.GAIN) to an anode of a gain-section diode (590a) disposed on a shared substrate of the tunable laser; and delivering a second bias current (I.sub.PH) to an anode of phase-section diode (590b) disposed on the shared substrate. The second bias current is less than the first bias current. When the burst mode signal transitions to be indicative of the burst-off state, the method also includes delivering the first bias current to the anode of the gain-section diode; and delivering the second bias current to the anode of the phase-section diode wherein the first bias current is less than the second bias current.

A light source device includes: a plurality of laser light sources, each configured to emit a light beam; a plurality of collimating lenses, each configured to collimate the light beam emitted from a corresponding one of the laser light sources; a first transmission diffraction grating configured to diffract and combine, in an identical diffraction angle direction, the light beams transmitted through the collimating lenses and incident on a single region at different incident angles; a sensor configured to detect a positional deviation in diffracted light beams that are diffracted and combined by the first transmission diffraction grating; and a plurality of wavelength selecting elements, each disposed on an optical path between a respective one of the collimating lenses and the first transmission diffraction grating and configured to select a wavelength of a corresponding one of the light beams incident on the first transmission diffraction grating.

It is provided a method for fabricating an electroabsorption modulated laser comprising generating a single mode laser section and an electroabsorption modulator section, comprising fabricating at least one n-doped layer of the laser section and at least one n-doped layer of the modulator section; generating an isolating section for electrically isolating at least the n-doped layer of the laser section and the n-doped layer of the modulator section from one another. Generating the isolating section comprises epitaxially growing at least one isolating layer and structuring the isolating layer before the generation of the n-doped layer of the laser section and the n-doped layer of the modulator section.

A monolithic integrated semiconductor random laser comprising substrate, lower confinement layer on the substrate, active layer on the lower confinement layer, upper confinement layer on the active layer, strip-shaped waveguide layer longitudinally made in middle of the upper confinement layer, P.sup.+ electrode layer divided into two segments and made on the waveguide layer and N.sup.+ electrode layer on a back face of the lower confinement layer, wherein the two segments correspond respectively to gain region and random feedback region. The random feedback region uses a doped waveguide to randomly feedback light emitted by the gain region and then generates random laser which is random in frequency and intensity. Further, the semiconductor laser is light, small, stable in performance and strong in integration.

It is provided a laser arrangement, having an electro-absorption-modulated laser, having a laser section and an electro-absorption modulator section; a current source for supplying the laser section with current; a DC voltage source that is arranged in addition to the current source and can be used to apply DC voltage to a diode structure of the electro-absorption modulator section; a driver with which an RF signal is able to be fed to the laser; and an electrical connection via which the driver is connected to the laser. The electrical connection provides a direct current connection between the driver and the laser such, and the driver is configured such, that a photocurrent that is generated in the electrode-absorption modulator section of the laser by illumination with light of the laser section at least partially flows to the driver and at least contributes to the energy supply of the driver.

A thermally tunable laser includes: a substrate; a laser resonator, wherein the laser resonator includes a gain section, and wherein the laser resonator includes a tuning section; a heating arrangement; a heat sink arrangement for dissipating a heat flow from the laser resonator to the heat sink arrangement; and a hole arrangement for influencing the heat flow from the laser resonator to the heat sink arrangement, wherein the hole arrangement is arranged between the substrate and the heat sink arrangement, wherein one or more holes of the hole arrangement include at least one hole being arranged within a horizontal range of the tuning section, so that a thermal resistance between the tuning section and the heat sink arrangement is increased.