A bulged, forward-acting rupture disc (10) and a pressure relief device (38) incorporating a rupture disc (10), having a line of opening (28) formed in the transition region (26) of the disc between the bulged section (12) and flange section (14) are provided. The line of opening (28) is a stress-concentrating feature that, in conjunction with a stress-intensifying edge (68) located on an associated outlet ring (42), facilitates opening of the disc (10) when exposed to a predetermined pressure acting upon the concave face (20) of the bulged section (12).

A bulged, forward-acting rupture disc (10) and a pressure relief device (38) incorporating a rupture disc (10), having a line of opening (28) formed in the transition region (26) of the disc between the bulged section (12) and flange section (14) are provided. The line of opening (28) is a stress-concentrating feature that, in conjunction with a stress-intensifying edge (68) located on an associated outlet ring (42), facilitates opening of the disc (10) when exposed to a predetermined pressure acting upon the concave face (20) of the bulged section (12).

Methods for singulating an optical waveguide material at a contour include directing a first laser beam onto a first side of the optical waveguide material to generate a first group of perforations in the optical waveguide material. A second laser beam is directed onto a second side of the optical waveguide material to generate a second group of perforations in the optical waveguide material. The second side is opposite the first side. The first group of perforations and the second group of perforations define a perforation zone at the contour. A third laser beam is directed at the perforation zone to singulate the optical waveguide material at the perforation zone.

Methods for singulating an optical waveguide material at a contour include directing a first laser beam onto a first side of the optical waveguide material to generate a first group of perforations in the optical waveguide material. A second laser beam is directed onto a second side of the optical waveguide material to generate a second group of perforations in the optical waveguide material. The second side is opposite the first side. The first group of perforations and the second group of perforations define a perforation zone at the contour. A third laser beam is directed at the perforation zone to singulate the optical waveguide material at the perforation zone.

An electromagnetic radiation system for directing an electromagnetic radiation beam (11) at a target (28) having a first arrangement (12) in which the radiation beam (11) is directed along a marking beam path that is within a marking range of the electromagnetic radiation system and a second arrangement (12, 15) in which the radiation beam (27) is directed along a different beam path (27) that is not within the marking range of the electromagnetic radiation system, wherein a positional relationship between the marking beam path (11) and the different beam path (27) satisfies a predetermined condition at the target (28) when the electromagnetic radiation system is at a predetermined distance (29) from the target (28).

An electromagnetic radiation system for directing an electromagnetic radiation beam (11) at a target (28) having a first arrangement (12) in which the radiation beam (11) is directed along a marking beam path that is within a marking range of the electromagnetic radiation system and a second arrangement (12, 15) in which the radiation beam (27) is directed along a different beam path (27) that is not within the marking range of the electromagnetic radiation system, wherein a positional relationship between the marking beam path (11) and the different beam path (27) satisfies a predetermined condition at the target (28) when the electromagnetic radiation system is at a predetermined distance (29) from the target (28).

A gas inlet element for a CVD reactor includes a cylindrical main body, which together with an outer wall, forms a gas outlet face. The outer wall surrounds at least one gas distribution chamber. A plurality of gas outlet openings originating in the gas distribution chamber open out into the gas outlet face. A cooling device includes a plurality of cooling channels running adjacently but separately in the outer wall, and the gas outlet openings extend between the cooling channels.

A mask includes a mask sheet including an upper surface and a lower surface facing the upper surface, the mask sheet including an opening passing through the upper surface and the lower surface; and a mask frame that supports the mask sheet, the mask sheet includes a protrusion adjacent to the opening and protruding from the lower surface, and a recess adjacent to the protrusion and recessed from the lower surface toward the upper surface of the mask sheet.

Separation lines are formed in a glass plate having first and second main surfaces by irradiating with laser light. The separation lines are configured of a product line corresponding to an outline of a glass article to be separated; and a release line. The product line includes a first in-plane void array configured of in-plane voids arranged on the first main surface; and internal void arrays for product line, each having an in-plane void. The release line includes internal void arrays for release line. A maximum length of the internal void array for product line L.sub.1max is equal to a maximum length of the internal void array for release line L.sub.2max, and a minimum length of the internal void array for product line L.sub.1min is greater than a minimum length of the internal void array for release line L.sub.2min; or the length L.sub.1max is greater than the length L.sub.2max.

Separation lines are formed in a glass plate having first and second main surfaces by irradiating with laser light. The separation lines are configured of a product line corresponding to an outline of a glass article to be separated; and a release line. The product line includes a first in-plane void array configured of in-plane voids arranged on the first main surface; and internal void arrays for product line, each having an in-plane void. The release line includes internal void arrays for release line. A maximum length of the internal void array for product line L.sub.1max is equal to a maximum length of the internal void array for release line L.sub.2max, and a minimum length of the internal void array for product line L.sub.1min is greater than a minimum length of the internal void array for release line L.sub.2min; or the length L.sub.1max is greater than the length L.sub.2max.