Abstract: A reflection-type terahertz spectrometer includes an input optical path through which terahertz waves are propagated, an irradiating mechanism that irradiates a sample with terahertz waves propagated through the input optical path, an output optical path through which terahertz waves exiting from the irradiating mechanism are propagated, and a detector that receives and detects the terahertz waves propagated through the output optical path. The irradiating mechanism has at least one planar interface and a refractive index greater than that of a peripheral region contacting the planar interface and is disposed between the input optical path and the output optical path such that the terahertz waves propagated through the input optical path to be incident on the planar interface undergo total internal reflection at the planar interface, and the sample is disposed in the peripheral region contacting the planar interface of the irradiating mechanism.

Abstract: A method for measuring a spectrum of a terahertz pulse includes generating a terahertz pulse using an ultrashort pulsed pumping light, generating a white light pulse using an ultrashort pulsed probe light, stretching and chirping the white light pulse modulating the chirped white light pulse such that the terahertz pulse and the chirped white light pulse irradiate into an electro-optic crystal synchronously, so that the chirped white light pulse is modulated by an electric field signal induced at the electro-optic crystal irradiated by the terahertz pulse, detecting a spectrum of chirped white light pulse modulated at the electro-optic modulating step by a multi-channeled detector, analyzing an electric field of the teraherz pulse irradiated to the electro-optic crystal from the spectrum of the chirped white light pulse detected by the multi-channeled spectrum detecting step, and transforming the analyzed electric field signal into a frequency spectrum of the terahertz pulse.

Abstract: A terahertz wave-generating semiconductor crystal includes a zincblende-type III-V compound semiconductor crystal that generates terahertz wave pulses upon application of an ultrashort light pulse in the optical communication band serving as a pump beam.

Abstract: A reflection-type terahertz spectrometer includes an input optical path through which terahertz waves are propagated, an irradiating mechanism that irradiates a sample with terahertz waves propagated through the input optical path, an output optical path through which terahertz waves exiting from the irradiating mechanism are propagated, and a detector that receives and detects the terahertz waves propagated through the output optical path. The irradiating mechanism has at least one planar interface and a refractive index greater than that of a peripheral region contacting the planar interface and is disposed between the input optical path and the output optical path such that the terahertz waves propagated through the input optical path to be incident on the planar interface undergo total internal reflection at the planar interface, and the sample is disposed in the peripheral region contacting the planar interface of the irradiating mechanism.

Abstract: A terahertz wave-generating semiconductor crystal includes a zincblende-type III-V compound semiconductor crystal that generates terahertz wave pulses upon application of an ultrashort light pulse in the optical communication band serving as a pump beam.

Abstract: A multi-channeled measuring method for measuring a spectrum of a terahertz pulse includes the steps of a terahertz pulse generating step for generating a terahertz pulse by using an ultrashort pulsed pumping light, a white light generating step for generating a white light pulse by using an ultrashort pulsed probe light, a stretching step for stretching and chirping the white light pulse generated at the white light pulse generating step, an electro-optic modulating step for modulating the chirped white light pulse stretched and chirped at the stretching step in such a manner that the terahertz pulse and the chirped white light pulse irradiate into an electro-optic crystal synchronously, so that the chirped white light pulse is modulated by an electric field signal induced at the electro-optic crystal irradiated by the terahertz pulse, a multi-channeled spectral detecting step for detecting a spectrum of chirped white light pulse modulated at the electro-optic modulating step by a multi-channeled detector, an

Abstract: A diamond high brightness ultraviolet ray emitting element employs the carrier high-density phase of a diamond as a light-emitting mechanism. It includes a diamond substrate, a first diamond layer formed on the diamond substrate, a second diamond layer formed on the first diamond layer and functioning as an emission layer, a third diamond layer formed on the second diamond layer, a first electrode formed on the first diamond layer, and a second electrode formed on the third diamond layer. The second diamond layer constitutes the carrier high-density phase formed by high-density excitation. The combination of the high-density excitation with the high-quality diamond can implement the device that has stable carrier high-density phase, and emission efficiency higher than a conventional device with low-density excitation.