Abstract: A terahertz wave generator 1 includes a nonlinear crystal 4, which is capable of generating a terahertz wave TH, a pumping beam emitter 2, which emits a pumping beam L1, a seed beam emitter 3, which is disposed so as to be parallel to a nonlinear crystal 4 and emits a seed beam L2, a first total reflection mirror 17 and a second total reflection mirror 18, which successively reflect the seed beam L2 emitted from the seed beam emitter 3 to cause the seed beam L2 to be incident on the nonlinear crystal 4, and a convex lens 6, which collects the seed beam L2.

Abstract: A pumping beam L1 is caused to be incident on an end surface 4A of a nonlinear crystal 4, and a seed beam L2, the diameter of which is increased by a concave lens 6, is collected and adjusted into a collimated beam by a convex lens 7 and caused to be incident on the end surface 4A described above. The pumping beam L1 and the seed beam L2 are caused to be incident on the end surface 4A with the pumping beam L1 and the seed beam L2 superimposed on each other, whereby the nonlinear crystal 4 generates a terahertz wave TH.

Abstract: A pumping beam L1 enters from a pumping beam projector 3 into one end surface 2a of a nonlinear crystal 2, the pumping beam L1 and idler wave L2 are generated from another end surface 2b of the nonlinear crystal 2. The pumping beam L1 emitted from the other end surface 2b of the nonlinear crystal 2 is reflected and re-enters as a pumping beam L? into the other end surface 2b and the idler wave L2 generated from the other end surface 2b of the nonlinear crystal is reflected by the reflection optical system 6 and re-enters as a seed beam L2? into the other end surface 2b. The idler wave L2 enters as the seed beam L2? together with the pumping beam L1? into the nonlinear crystal and thus a terahertz wave with a large output and including a plurality of wavelengths can be generated.

Abstract: A pumping beam L1 enters from a pumping beam projector 3 into one end surface 2a of a nonlinear crystal 2, the pumping beam L1 and idler wave L2 are generated from another end surface 2b of the nonlinear crystal 2. The pumping beam L1 emitted from the other end surface 2b of the nonlinear crystal 2 is reflected and re-enters as a pumping beam L? into the other end surface 2b and the idler wave L2 generated from the other end surface 2b of the nonlinear crystal is reflected by the reflection optical system 6 and re-enters as a seed beam L2? into the other end surface 2b. The idler wave L2 enters as the seed beam L2? together with the pumping beam L1? into the nonlinear crystal and thus a terahertz wave with a large output and including a plurality of wavelengths can be generated.

Abstract: Pumping beam L1 is caused to be incident on an end surface 4A of a nonlinear crystal 4, and seed beam L2 the diameter of which is increased by a concave lens 6 is collected and adjusted into a collimated beam by a convex lens 7 and is caused to be incident on the end surface 4A described above. As described above, the pumping beam L1 and the seed beam L2 are caused to be incident on the end surface 4A with the pumping beam L1 and the seed beam L2 superimposed on each other, whereby the nonlinear crystal 4 generates terahertz wave TH. Since the diameter of the seed beam L2 described above is increased by the concave lens 6, the diameter of the seed beam L2 incident on the end surface 4A can be greater than the diameter of the seed beam generated by a terahertz wave generator of related art shown in FIG. 3. The area where the pumping beam L1 and the seed beam L2 incident on the end surface 4A are superimposed on each other can be greater than the area in the terahertz wave generator of related art.

Abstract: A terahertz wave generator 1 includes a nonlinear crystal 4, which is capable of generating terahertz wave TH, a pumping beam emitter 2, which emits pumping beam L1, a seed beam emitter 3, which is disposed so as to be parallel to the nonlinear crystal 4 and emits seed beam L2, a first total reflection mirror 17 and a second total reflection mirror 18, which successively reflect the seed beam L2 emitted from the seed beam emitter 3 to cause the seed beam L2 to be incident on the nonlinear crystal 4, and a convex lens 6, which collects the seed beam L2. When the pumping beam L1 and the seed beam L2 are caused to be incident on the nonlinear crystal 4 with the pumping beam L1 and the seed beam L2 superimposed on each other, the nonlinear crystal 4 generates the terahertz wave TH.

Abstract: In a terahertz wave generation apparatus including a first non-linear optical crystal 3 on which first laser L1 and second laser L2 from laser generation means 2 are incident to generate terahertz wave TH1, the laser generation means includes a second non-linear optical crystal 7 on which laser having the same wavelength as that of the second laser is incident to generate idler light L1 including a plurality of wavelengths, and makes the idler light L1 generated from the second non-linear optical crystal incident on the first non-linear optical crystal as the first laser L1, to generate terahertz wave including a plurality of wavelengths from the first non-linear optical crystal 3, and wavelength selection means including a transmission section which transmits an idler light having the specific wavelength in the idler light including the plurality of wavelengths can be provided, as needed.

Abstract: In a terahertz wave generation apparatus including a first non-linear optical crystal 3 on which first laser L1 and second laser L2 from laser generation means 2 are incident to generate terahertz wave TH1, the laser generation means includes a second non-linear optical crystal 7 on which laser having the same wavelength as that of the second laser is incident to generate idler light L1 including a plurality of wavelengths, and makes the idler light L1 generated from the second non-linear optical crystal incident on the first non-linear optical crystal as the first laser L1, to generate terahertz wave including a plurality of wavelengths from the first non-linear optical crystal 3, and wavelength selection means including a transmission section which transmits an idler light having the specific wavelength in the idler light including the plurality of wavelengths can be provided, as needed.