Patent attributes
The present invention includes a slanted periodically poled device 12 including a light input surface 12a and a light output surface 12b parallel to each other and a terahertz wave input surface 12c orthogonal to the light input surface 12a and the light output surface 12b, a pump beam source 14 which emits pump beam 1 perpendicularly to the light input surface 12a, and a photodetector 16 which detects an up-conversion signal beam A converted from a terahertz wave 3 emitted perpendicularly from the light output surface 12b. The slanted periodically poled device 12 is configured to generate the up-conversion signal beam A in the same direction as and in parallel with the pump beam 1 by quasi phase matching between the terahertz wave 3 perpendicularly incident from the terahertz wave input surface 12c and the pump beam 1.
