Abstract: In an embodiment, the semiconductor laser (1) comprises a semiconductor layer sequence (2) in which an active zone (22) for generating laser radiation (L) is located. Several electrical contact surfaces (5) serve for external electrical contacting of the semiconductor layer sequence (2). Several parallel ridge waveguides (3) are formed from the semiconductor layer sequence (2) and configured to guide the laser radiation (L) along a resonator axis, so that there is a separating trench (6) between adjacent ridge waveguides. At least one electrical feed (4) serves from at least one of the electrical contact surfaces (5) to guide the current to at least one of the ridge waveguides (3). A distance (A4) between the ridge waveguides is at most 50 ?m. The ridge waveguides (3) are electrically controllable individually or in groups independently of one another and/or configured for single-mode operation.

Abstract: The invention relates to an exothermic molding material mixture for producing feeders for casting aluminum, comprising at least: - a fireproof base molding material; - a binder; - a proportion of an oxidizable metal of from 5 to 18% by weight relative to the molding material mixture; - an oxidizing agent at a proportion of 10 to 50% by weight relative to the quantity of oxidizing agent required for completely oxidizing the oxidizable metal; and - an igniter for oxidizing the oxidizable metal at a proportion of 15 to 50% by weight relative to the quantity of the oxidizable metal. A feeder made of the exothermic molding material mixture ignites reliably, even at low temperatures, and is characterized by low heat emission. It is therefore particularly suitable for casting aluminum.