Abstract: A cooling jacket casting core for the production of a cylinder head of an internal combustion engine. The cooling jacket casting core has a slot running at least in part substantially in the direction of a crankshaft longitudinal axis and separating the cooling jacket casting core in at least one section. The slot can run at least in part in an impression of the cooling jacket and can have at least one elevation arranged perpendicular to the longitudinal axis of the cooling jacket casting core.

Abstract: A cooling jacket casting core according to the invention for the production of a cylinder head of an internal combustion engine comprises at least one impression of a cooling jacket. The cooling jacket casting core itself has a slot running at least in part substantially in the direction of a crankshaft longitudinal axis and separating the cooling jacket casting core in at least one section. In accordance with a further development, the slot runs at least in part in the impression of the cooling jacket. The slot preferably has at least approximately one elevation arranged perpendicular to the longitudinal axis of the cooling jacket casting core. This longitudinal extension of the slot runs parallel to a crankshaft associated with the cylinder head in an internal combustion engine.

Abstract: An optical duplexer, configured as a directional coupler, is integrated into an optical coupling arrangement with a fiber optic pigtail, constructed in planar-optical hybrid technology on a substrate (1). To reduce the required surface area and decrease optical cross talk, the branch of the directional coupler (waveguide 6, branch 7) is sharply bent. The bend is equipped with a reflecting mirror (11) integrated opposite the inner edge (10) of the bend. Furthermore, the waveguiding end of the bent branch (7) is equipped with a cylindrical lens. A laser diode (8) is located before this, and a photodiode (5) is located before the angled end of the straight-line integrated waveguide (2).

Abstract: A semiconductor device is operated as an optical filter. The semiconductor device has a substrate and a monolithically integrated branched waveguide structure disposed above the substrate, portions of the waveguide structure being divided into a plurality of regions by troughs, one of the regions being a branching region. Light is radiated into the waveguide structure at an end face of one of the regions and currents that are smaller than respective laser threshold currents of the regions flow through the regions, including the branching region, perpendicular to a propagation direction of light through the waveguide.

Abstract: A semiconductor laser is provided monolithically integrated on a substrate and has a cavity layer extending above a plane that is coplanar with a base surface of the substrate, is branched and includes a plurality of separately controllable regions. The laser is operated by changing charge carrier density in at least one of the regions so that it emits light at one of a first wavelength and a second wavelength in correspondence with the charge carrier density change.

Abstract: An interferometric semiconductor laser includes a cavity in the form of a Y and at east three individually actuatable active segments. A central segment couples together the individually actuatable active segments. The central segment is an active or passive segment that acts as a beam divider. The arrangement of the segments forms two resonator paths which contain at least one common active segment. At least one resonator path includes an active segment that does not belong to the other resonator path. In the absence of, or with the same actuation of the active segments, the optical path length of one resonator path differs from the optical path length of the other resonator path.

Abstract: A semiconductor laser that is monolithically integrated on a substrate and whose cavity has a branched structure that is simply contiguous in a topological sense, and which includes a plurality of regions that enclose the cavity, is operated as a mode-locked semiconductor laser, with an alternating current flowing through at least one region in addition to a direct current. The frequency of the alternating current is related to the reciprocal of the round-trip time or an integral multiple of this reciprocal of light pulses generated by the alternating current in the semiconductor laser.

Abstract: An optical device includes a semiconductor laser monolithically integrated on a substrate having a branched cavity extending above a plane that is coplanar with a base surface of the substrate, and an adjustable optical power light source for radiating light into the cavity of the semiconductor laser thereby controlling the operation of the semiconductor laser optically.

Abstract: A semiconductor laser which includes a controllable beam splitter has three segments including laser-active zones and a monitor diode forming a cross-shaped laser connected with one another by way of the beam splitter. The beam splitter is equipped with electrodes for controlling optical coupling between the segments.