Abstract: An optical modulator, a substrate for an optical modulator, a method of manufacturing an optical modulator, and a method of manufacturing a substrate for an optical modulator that can reduce a propagation loss are provided. An optical modulator 1 according to an embodiment includes: a base substrate 10; a waveguide substrate 20 disposed over the base substrate 10 and including an electro-optic effect; a waveguide 23 formed on the waveguide substrate 20 for performing optical modulation; and an electrode 40 configured to apply a voltage to the waveguide 23. Here, the base substrate 10 and the waveguide substrate 20 are made of the same material, the waveguide 23 is formed inside the waveguide substrate 20, and a refractive index of the waveguide substrate 20 is larger than a refractive index of the base substrate 10.

Abstract: An optical modulator, a substrate for an optical modulator, a method of manufacturing an optical modulator, and a method of manufacturing a substrate for an optical modulator that can reduce a propagation loss are provided. An optical modulator 1 according to an embodiment includes: a base substrate 10; a waveguide substrate 20 disposed over the base substrate 10 and including an electro-optic effect; a waveguide 23 formed on the waveguide substrate 20 for performing optical modulation; and an electrode 40 configured to apply a voltage to the waveguide 23. Here, the base substrate 10 and the waveguide substrate 20 are made of the same material, the waveguide 23 is formed inside the waveguide substrate 20, and a refractive index of the waveguide substrate 20 is larger than a refractive index of the base substrate 10.

Abstract: In the case of forming a scribe line by irradiating a laser in an ultraviolet range in one stroke, the glass bending strength after glass is cut is about 50 MPa or less, and the glass is likely to be subjected to crack damage during use as liquid crystal panel glass or the like. In a glass cutting method in which a portion to be cut of glass 4 is irradiated with a pulse laser 2 in one stroke of relative movement to form a scribe line 7, and then the glass is cut by applying a break force to the scribe line 7, a pulse laser of an ultraviolet range is used as the pulse laser 2, and the pulse laser 2 is irradiated while the pulse laser 2 is being relatively moved so that the total number of pulses at each irradiation portion is in a range of 2,667 to 8,000 pulses, whereby the scribe line 7 is formed to a depth of 1.8 to 6.3% of the thickness of the glass 4.