Prism member, terahertz-wave spectroscopic measurement device, and terahertz-wave spectroscopic measurement method

1. A prism member for use in transmission spectrometry of an object to be measured employing a terahertz wave, the prism member comprising:

an entrance surface for arranging a terahertz-wave generator for generating a terahertz wave in response to pump light incident thereon;

an arrangement part for arranging the object;

an exit surface for arranging a terahertz-wave detector for detecting a correlation between the terahertz wave transmitted through the object in the arrangement part and probe light;

a first optical surface for collimating or condensing the terahertz wave incident thereon from the entrance surface toward the arrangement part; and

a second optical surface for condensing the terahertz wave transmitted through the arrangement part toward the exit surface;

wherein the arrangement part forms a depression adapted to be filled with a liquid incapable of dissolving the object therein, and

wherein the depression includes a first refractive surface for refracting the terahertz wave from the first optical surface toward the object and a second refractive surface for refracting the terahertz wave transmitted through the object toward the second optical surface.

2. A prism member according to claim 1 , wherein the object is a solid, and wherein the arrangement part has a support part for supporting the object.

3. A prism member according to claim 1 , wherein the object is a liquid, and wherein the arrangement part has a support part for supporting a cell containing the object.

4. A terahertz-wave spectrometer for performing transmission spectrometry of an object to be measured by using a terahertz wave, the spectrometer comprising:

a light source for emitting laser light;

a branching unit for splitting the laser light emitted from the light source into pump light and probe light; and

a prism member;

wherein the prism member has:

an entrance surface for arranging a terahertz-wave generator for generating a terahertz wave in response to the pump light incident thereon;

an arrangement part for arranging the object;

an exit surface for arranging a terahertz-wave detector for detecting a correlation between the terahertz wave transmitted through the object in the arrangement part and the probe light;

a first optical surface for collimating or condensing the terahertz wave incident thereon from the entrance surface toward the arrangement part; and

a second optical surface for condensing the terahertz wave transmitted through the arrangement part toward the exit surface;

wherein the arrangement part forms a depression adapted to be filled with a liquid incapable of dissolving the object therein, and

wherein the depression includes a first refractive surface for refracting the terahertz wave from the first optical surface toward the object and a second refractive surface for refracting the terahertz wave transmitted through the object toward the second optical surface.

5. A terahertz-wave spectrometer according to claim 4 , wherein the object is a solid, and wherein the arrangement part has a support part for supporting the object.

6. A terahertz-wave spectrometer according to claim 4 , wherein the object is a liquid, and wherein the arrangement part has a support part for supporting a cell containing the object.

7. A terahertz-wave spectrometric method for performing transmission spectrometry of an object to be measured by using a terahertz wave,

the method using a prism member having:

an entrance surface for arranging a terahertz-wave generator for generating a terahertz wave in response to pump light incident thereon,

an arrangement part for arranging the object,

an exit surface for arranging a terahertz-wave detector for detecting a correlation between the terahertz wave transmitted through the object in the arrangement part and probe light,

a first optical surface for collimating or condensing the terahertz wave incident thereon from the entrance surface toward the arrangement part, and

a second optical surface for condensing the terahertz wave transmitted through the arrangement part toward the exit surface,

wherein the arrangement part forming a depression adapted to be filled with a liquid incapable of dissolving the object therein; and

the method comprising:

arranging the object in a state where the depression is filled with the liquid incapable of dissolving the object therein; and

measuring an optical constant concerning the object according to the terahertz wave transmitted through the object,

wherein the prism member has the arrangement part constituted by the depression including a first refractive surface for refracting the terahertz wave from the first optical surface toward the object and a second refractive surface for refracting the terahertz wave transmitted through the object toward the second optical surface.

8. A terahertz-wave spectrometric method according to claim 7 , wherein the object is a solid, and wherein the prism member has a support part for supporting the object in the arrangement part.

9. A terahertz-wave spectrometric method according to claim 7 , wherein the object is a liquid, and wherein the prism member has a support part for supporting a cell containing the object.

10. A terahertz-wave spectrometric method according to claim 7 , wherein a liquid incapable of absorbing the terahertz wave is used as the liquid incapable of dissolving the object therein.

11. A terahertz-wave spectrometric method according to claim 7 , wherein a fluorine-based inert liquid is used as the liquid incapable of dissolving the object therein.

12. A terahertz-wave spectrometric method according to claim 7 , wherein a silicone oil is used as the liquid incapable of dissolving the object therein.