A laser device is provided for generating an optical wave at a laser frequency, including (i) a semiconductor element having a gain region with quantum wells, the gain region being located between a first mirror and an exit region defining an optical microcavity, (ii) a second mirror distinct from the semiconductor element and arranged so as to form with the first mirror an external optical cavity including the gain region, (iii) a pump for pumping the gain region so as to generate the optical wave, wherein the optical microcavity with the gain region and the external optical cavity are arranged so that a spectral ratio between the Half Width Half Maximum (HWHM) spectral bandwidth of the modal gain and a free spectral range of the external cavity in the range of 2 to 50.

One embodiment is a wide stripe semiconductor waveguide, which is cleaved at a Talbot length thereof, the wide stripe semiconductor waveguide having facets with mirror coatings. A system provides for selective pumping the wide stripe semiconductor waveguide to create and support a Talbot mode. In embodiments according to the present method and apparatus the gain is patterned so that a single unique pattern actually has the highest gain and hence it is the distribution that oscillates.

One embodiment is a wide stripe semiconductor waveguide, which is cleaved at a Talbot length thereof, the wide stripe semiconductor waveguide having facets with mirror coatings. A system provides for selective pumping the wide stripe semiconductor waveguide to create and support a Talbot mode. In embodiments according to the present method and apparatus the gain is patterned so that a single unique pattern actually has the highest gain and hence it is the distribution that oscillates.

A laser device is provided for generating an optical wave at a laser frequency, including (i) a semiconductor element having a gain region with quantum wells, the gain region being located between a first mirror and an exit region defining an optical microcavity, (ii) a second mirror distinct from the semiconductor element and arranged so as to form with the first mirror an external optical cavity including the gain region, (iii) a pump for pumping the gain region so as to generate the optical wave, wherein the optical microcavity with the gain region and the external optical cavity are arranged so that a spectral ratio between the Half Width Half Maximum (HWHM) spectral bandwidth of the modal gain and a free spectral range of the external cavity in the range of 2 to 50.

An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.

A surface emitting element includes: a substrate having a first surface and a second surface opposed to the first surface; an epitaxial growth layer including a first semiconductor layer that is of a first electrically conductive type, an active layer, and a second semiconductor layer that is of a second electrically conductive type sequentially stacked on the second surface by epitaxial growth, the epitaxial growth layer having distributions in thickness and resonator length; an electrode electrically coupled to the first semiconductor layer; a current injection region formed on a surface of the second semiconductor layer on side opposite to the substrate, the current injection region being electrically coupled to the second semiconductor layer and having light transparency; a first reflective layer formed on the first surface at a position corresponding to a predetermined thickness of the epitaxial growth layer, the first reflective layer including a curve mirror structure; and a second reflective layer formed on a surface of the current injection region on side opposite to the second semiconductor layer.

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.

Systems and methods are provided for refractive index engineering for brightness enhancement and kink suppression in optical emitter devices. An example optical emitter device may include a first region that includes a first semiconductor material, an active region located on the first region, with the active region including a pumped active region between a front end and a back end of the optical emitter device, and a plurality of loss structures arranged along at least a portion of at least one side of the pumped active region. The plurality of loss structures may be arranged between the front end and the back end of the optical emitter device. The plurality of loss structures may include two or more continuous etched lines. The plurality of loss structures may include two or more discontinuous etched features.