Abstract: A method of making a bulk crystal substrate of a GaN single crystal includes the steps of forming a molten flux of an alkali metal in a reaction vessel and causing a growth of a GaN single crystal from the molten flux, wherein the growth is continued while replenishing a compound containing N from a source outside the reaction vessel.

Abstract: A group-III nitride crystal growth method comprises the steps of: a) preparing a mixed molten liquid of an alkaline material and a substance at least containing a group-III metal; b) causing growth of a group-III nitride crystal from the mixed molten liquid prepared in the step a) and a substance at least containing nitrogen; and c) creating a state in which nitrogen can be introduced into the molten liquid prepared by the step a).

Abstract: Disclosed is a piezoelectric resonator that has a piezoelectric plate that has formed thereon a pair of main electrodes and has formed thereon a second electrode surrounding the peripheral edge of the main electrode with a gap being provided between the second electrode and a peripheral edge of the main electrode. The material of the main electrode and the material of the second electrode are differentiated from each other. As the material of the second electrode there is used a material the density of that is lower than the material of the main electrode. With this construction, there is obtained means for suppressing the occurrence of spurious due to an inharmonic mode generating in the high frequency piezoelectric resonator.

Abstract: The invention provides a lamination apparatus including using a sheet roll with an encoder plate secured to the end face of an adhesive sheet roll, and a slit pattern on the encoder plate being detected by a photointerruptor. In addition, a duty ratio is calculated on the basis of rectangular pulse signals output from the photointerruptor, thereby identifying the type of the adhesive sheet roll. Further, the period of the rectangular pulse signals output from the photointerruptor is compared with a predetermined value, such that the trailing edge of the adhesive sheet of the adhesive sheet roll is detected at the time point when the period is smaller than the predetermined value.

Abstract: A light emitting diode chip includes a substrate carrying thereon a number of light emitting diodes aligned in a row to form an array for producing a number of optical beams parallel to each other in a first direction, and monitoring element provided monolithically on the substrate for detecting the power of the optical beams produced by the light emitting diodes, wherein the monitoring element includes: a reference light emitting diode having a structure identical to the light emitting diodes in the array for producing an optical beam in a second direction perpendicular to the first direction; and a photodiode having a structure identical to the light emitting diodes in the array and separated from the reference light emitting diode by an isolation groove for detecting the optical beam produced by the reference light emitting diode.

Abstract: A semiconductor device includes a semiconductor substrate, and a plurality of semiconductor layers formed on the semiconductor substrate and forming a concave lateral surface, the semiconductor layers including an active layer for either emitting light or receiving light, wherein the concave lateral surface is used as either a light-emitting surface or a light-receiving surface.