Abstract: There are provided a manufacturing method of a glass member capable of being cut well without causing a decrease in strength even by using laser light to form a reformed region inside a glass and cutting the glass along the reformed region, and a glass member obtained by the manufacturing method. A glass member 100 having, as a main body thereof, a glass substrate 110 including: strengthened principal surfaces 110a and an end surface; a reformed region R formed on the end surface made by light radiated to be focused thereto, in which a tension stress (CT) of a center portion in a tension stress region, a fracture toughness (K1c) of the glass substrate, and a crack initiation load (CIL) of the glass substrate satisfy a predetermined expression.

Abstract: To provide an optical glass, being an optical glass manufactured by a cutting method using laser light, more increases strength to make it difficult to cause breakage when external force such as impact is applied thereon, or more increases a bonding strength to a casing to more increase reliability of the product. An optical glass 100 is a plate-shaped optical glass to be bonded to a casing to cover an opening of the casing, the optical glass being made of a glass substrate 110 including: a first principal surface 110A being the side to be bonded to the casing; a second principal surface 110B being the side opposite to the first principal surface; and a cut surface cut along a reformed region R formed therein by light radiated to be focused therein, in which the reformed region R exists unevenly at the second principal surface 110B side.

Abstract: Provided are a method of cutting a glass substrate which is capable of secure cutting by a simpler operation and an optical glass having high bending strength and dimension accuracy obtained by that method. The method of cutting the glass substrate comprising: forming selectively a plurality of reformed portions with a crack extending in the glass substrate from at least one of the plurality of reformed portions by radiating light to be focused inside the glass substrate so as to form a reformed region; and making a fracture occur in a thickness direction of the glass substrate along the reformed region so as to cut the glass substrate, wherein the crack has a tip portion at a depth of 3 to 20% of a thickness of the glass substrate from a cut surface, and an optical glass 100 is obtained by the above cutting method.

Abstract: There are provided a manufacturing method of a glass member capable of being cut well without causing a decrease in strength even by using laser light to form a reformed region inside a glass and cutting the glass along the reformed region, and a glass member obtained by the manufacturing method. A glass member 100 having, as a main body thereof, a glass substrate 110 including: strengthened principal surfaces 110a and an end surface; a reformed region R formed on the end surface made by light radiated to be focused thereto, in which a tension stress (CT) of a center portion in a tension stress region, a fracture toughness (K1c) of the glass substrate, and a crack initiation load (CIL) of the glass substrate satisfy a predetermined expression.

Abstract: To provide an optical glass, being an optical glass manufactured by a cutting method using laser light, more increases strength to make it difficult to cause breakage when external force such as impact is applied thereon, or more increases a bonding strength to a casing to more increase reliability of the product. An optical glass 100 is a plate-shaped optical glass to be bonded to a casing to cover an opening of the casing, the optical glass being made of a glass substrate 110 including: a first principal surface 110A being the side to be bonded to the casing; a second principal surface 110B being the side opposite to the first principal surface; and a cut surface cut along a reformed region R formed therein by light radiated to be focused therein, in which the reformed region R exists unevenly at the second principal surface 110B side.

Abstract: To provide a cutting method for a glass substrate which can be easily cut by efficiently forming a modified region inside the glass substrate, a glass substrate, and a near-infrared cut filter glass. The cutting method for a glass substrate according to the present invention includes the steps of: radiating light to be focused inside a glass substrate to selectively form a modified region inside the glass substrate; and causing a crack in a thickness direction of the glass substrate starting from the modified region and cutting the glass substrate along the modified region, in which the glass substrate has a fracture toughness of 0.1 MPa·m1/2 to 0.74 MPa·m1/2.