A laser resonator includes an active material, which amplifies light associated with an optical gain of the resonator, and passive materials disposed in proximity with the active material. The resonator oscillates over one or more optical modes, each of which corresponds to a particular spatial energy distribution and resonant frequency. Based on a characteristic of the passive materials, for the particular spatial energy distribution corresponding to at least one of the optical modes, a preponderant portion of optical energy is distributed apart from the active material. The passive materials may include a low loss material, which stores the preponderant optical energy portion distributed apart from the active material, and a buffer material disposed between the low loss material and the active material, which controls a ratio of the optical energy stored in the low loss material to a portion of the optical energy in the active material. A Vernier grating and tuning mechanism can be used to tune the low-noise laser.

A DFB laser having a reduced fill factor and reduced loss. A plurality of spaced-apart contact openings are etched into a dielectric layer situated on top of a laser ridge having a DFB grating layer so that electrical contact between the metal top contact layer and the DFB gratings is made only in the etched openings, since all other areas of the top surface of the DFB-grated laser ridge are insulated from the metal contact layer by the dielectric. The size and shape of contact openings and their spacing are configured so that the ratio of the total area of the openings to the total area of the laser ridge provides a fill factor of less than 100%.

A quantum cascade laser device includes a substrate, a semiconductor stacked body and a first electrode. The semiconductor stacked body includes an active layer and a first clad layer. The active layer is configured to emit infrared laser light by an intersubband optical transition. A ridge waveguide is provided in the semiconductor stacked body. A distributed feedback region is provided along a first straight line. The ridge waveguide extends along the first straight line. The first electrode is provided at an upper surface of the distributed feedback region. A diffraction grating is arranged along the first straight line. The distributed feedback region includes a an increasing region where a length of the diffraction grating along a direction orthogonal to the first straight line increases from one end portion of the distributed feedback region toward another end portion of the distributed feedback region.

A laser including: a gain chip; an external cavity incorporating a Bragg grating; and a baseplate; wherein a first end of the gain chip has a high reflectivity facet forming a first end of the laser cavity; a second end of the gain chip has a low reflectivity facet; and a second part of the external cavity comprises a Bragg grating, supported by the baseplate, the temperature of the baseplate being maintained through a feedback loop; wherein the optical length of the external cavity is at least an order of magnitude greater than the optical length of the gain chip; wherein the Bragg grating is physically long and occupies a majority of the length of the external cavity and is apodized to control the sidemodes of the grating reflection.

A semiconductor laser diode system may include a single longitudinal mode laser diode and a feedback system that monitors and controls the emission characteristics of the laser diode. The laser diode may include a gain medium and an optical feedback device. The feedback system may include a wavelength discriminator, an optical detector, a microprocessor, and a laser controller. Such a semiconductor laser diode system may be used to produce laser light having coherence length, wavelength precision, and wavelength stability that is equivalent to that of a gas laser. Accordingly, such a semiconductor laser diode system may be used in place of a traditional gas laser.

A housing for an optically pumped semiconductor (OPS) laser resonator is terminated at one end thereof by an OPS-chip. The laser resonator is assembled on a platform with the OPS-chip at one end of the platform. The platform is fixedly attached to a baseplate at the OPS-chip end of the platform. The remainder of the platform extends over the baseplate with a gap between the platform and the baseplate. A pump-laser is mounted directly on the baseplate and delivers pump radiation to the OPS-chip.

The present invention relates to a first container with an internal space for accommodating a vertical external cavity surface emitting laser device. Said first container hermetically seals said internal space from an external space, wherein said first container has at least one wall with at least one first through-opening. Said at least one first through-opening is adapted for passage of an optical pump beam from the external space into the internal space, and/or for passage of a laser emission beam from the internal space into the external space. Moreover, said at least one first through-opening is hermetically sealed by a sealing mirror, wherein said sealing mirror is adapted to form an external cavity of the vertical external cavity surface emitting laser device with a second mirror in the internal space. Furthermore, the present invention relates to laser device with such a first container and to an assembly method of the laser device.

Waveguide Bragg gratings, optical reflectors and lasers including optical reflectors are disclosed. The optical reflectors include a waveguide, perturbations proximate to the waveguide to create a Bragg grating in the waveguide, and a DC index control structure positioned to vary the DC index along at least a portion of the Bragg grating. In laser embodiments, the waveguide may be coupled to the second end of a semiconductor gain element to form an external cavity having an optical length and a cavity phase. The gain element and optical reflector may be monolithically integrated on a substrate or separate structures.

A grating device includes a support substrate, an optical material layer 11 disposed on the support substrate and having a thickness of 0.5 m or more and 3.0 m or less, a ridge optical waveguide formed by a pair of ridge grooves in the optical material layer and having a light-receiving surface for receiving a semiconductor laser light and a light-emitting surface for emitting light having a desired wavelength, a Bragg grating 12 comprising convexes and concaves formed in the ridge optical waveguide, and a propagating portion 13 disposed between the light-receiving surface and the Bragg grating. The relationships represented by the following Formulas (1) to (4) are satisfied:
0.8 nmG6.0 nm(1);
10 mLb300 m(2);
20 nmtd250 nm(3); and
nb1.8(4).

A technique relates to a superchannel. Laser cavities include a first laser cavity, a next laser cavity, through a last laser cavity. Modulators include a first modulator, a next modulator, through a last modulator, each having a direct input, an add port, and an output. A concatenated arrangement of the laser cavities is configured to form the superchannel, which includes the last laser cavity coupled to the direct input of the last modulator, and the output of the last modulator coupled to the add port of the next modulator. The arrangement includes the next laser cavity coupled to direct input of the next modulator, and the output of the next modulator coupled to add port of first modulator, along with the first laser cavity coupled to direct input of the first modulator, and the output of first modulator coupled to input of a multiplexer, thus forming the superchannel into multiplexer.