Solid-state light source apparatus

• US 6,738,397 B2
• Filed: 04/15/2002
• Issued: 05/18/2004
• Est. Priority Date: 04/27/2001
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kurimura, Sunao, Yamamoto, Shuhei, Taira, Takunori, Hirano, Yoshihito, Shoji, Ichiro
• Primary Examiner(s): Ip, Paul
• Assistant Examiner(s): NGUYEN, PHILLIP
• Application Number:
  US10/121,705
• Publication Number:
  US 20020158260A1
• Time in Patent Office: 764 Days
• Field of Search: 372/21, 372/28, 372/29.011, 372/38.06, 372/22, 372/20, 372/211, 359/248
• US Class Current: 372/21
• CPC Class Codes: G02F 1/3534 Three-wave interaction, e.g. sum-difference frequency generation G02F1/3532 takes precedence
• CPC Class Codes: G02F 2203/13 involving THZ radiation

Abstract

A solid-state light source apparatus includes a first excitation laser light source for outputting a laser beam of a first wavelength, a second excitation laser light source for outputting a laser beam of a second wavelength, a difference frequency between the laser beam of the first wavelength and the laser beam of the second wavelength being in a terahertz band, and a semiconductor pseudo phase matching device which is disposed at a place where a first optical axis of the laser beam of the first wavelength overlaps with a second optical axis of the laser beam of the second wavelength, and generates a terahertz beam in a direction coaxial with the first and second optical axes on the basis of irradiation of the laser beams of the first and second wavelengths. Thus, high output and high efficiency terahertz wave generation can be easily and certainly realized while a narrow line width characteristic is maintained.

Claims

1. A solid-state light source apparatus, comprising:

a first excitation laser light source for outputting a laser beam of a first wavelength;

a second excitation laser light source for outputting a laser beam of a second wavelength, a difference frequency between the laser beam of the first wavelength and the laser beam of the second wavelength being in a terahertz band; and

a nonlinear wavelength conversion device having a plurality of semiconductor materials united with each other by diffused junction, the nonlinear wavelength conversion device disposed at a place where a first optical axis of the laser beam of the first wavelength overlaps with a second optical axis of the laser beam of the second wavelength, and generates a terahertz beam in a direction coaxial with the first and second optical axes on the basis of irradiation of the laser beams of the first and second wavelengths.

2. A solid-state light source apparatus according to claim 1, wherein the first excitation laser light source is a fixed wavelength laser, and the second excitation laser light source is a tunable wavelength laser.

3. A solid-state light source apparatus according to claim 2, wherein the first excitation laser light source is a Nd:

YAG laser, and the second excitation laser light source is a Yb;

YAG laser.

4. A solid-state light source apparatus according to claim 3, wherein

the first excitation laser light source outputs a monochromatic beam of the first wavelength of 1.064 μ m, and

the second excitation laser light source outputs a monochromatic beam of the second wavelength in a band of 1 μ

m.

5. A solid-state light source apparatus according to claim 1, wherein the first and second excitation laser light sources are Yb:

YAG lasers.

6. A solid-state light source apparatus according to claim 1, wherein the first excitation laser light source is a Nd:

YLF laser, and the second excitation laser light source is a Yb;

YAG laser.

7. A solid-state light source apparatus according to claim 1, wherein the nonlinear wavelength conversion device is a semiconductor pseudo phase matching device comprising said plurality of semiconductor materials united with each other by diffused junction in which a plurality of first semiconductor materials of said plurality of semiconductor materials, each having a length of Λ

/2 in a direction coaxial with the first and second optical axes and a plurality of second semiconductor materials of said plurality of semiconductor materials, each having a length of Λ

/2 are united with one another by diffused junction, and the first and second semiconductor materials are disposed so that directions vertical to the first and second optical axes are [001] axes, directions of the respective [001] axes are parallel to one another, and the directions of the [001] axes are alternately inverted.

8. A solid-state light source apparatus according to claim 7, wherein the first and the second semiconductor materials of the semiconductor pseudo phase matching device are transparent materials in a terahertz region.

9. A solid-state light source apparatus according to claim 8, wherein the first and the second semiconductor materials of the semiconductor pseudo phase matching device are made of GaP.

10. A solid-state light source apparatus according to claim 8, wherein the first and the second semiconductor materials of the semiconductor pseudo phase matching device are made of GaAs.

11. A solid-state light source apparatus according to claim 1, wherein the nonlinear wavelength conversion device is a semiconductor pseudo phase matching device comprising said plurality of semiconductor materials united with each other by diffused junction in which a plurality of first semiconductor materials of said plurality of semiconductor materials, each having a length of Λ

/2 in a direction coaxial with the first and second optical axes and a plurality of second semiconductor materials of said plurality of semiconductor materials, each having a length of Λ

/2 are united with one another by diffused junction, and the first and second semiconductor materials are disposed so that azimuths of the first and second semiconductor materials are the same as a direction perpendicular to the first and second optical axes and directions thereof are alternately inverted.

12. A solid-state light source apparatus according to claim 11, wherein the first and second semiconductor materials of the semiconductor pseudo phase matching device are transparent materials in a terahertz region.

13. A solid-state light source apparatus according to claim 12, wherein the first and second semiconductor materials of the semiconductor pseudo phase matching device are GaP.

14. A solid-state light source apparatus according to claim 12, wherein the first and second semiconductor materials of the semiconductor pseudo phase matching device are GaAs.

15. A solid-state light source apparatus, comprising:

a first laser light source for outputting a first laser beam having a first wavelength;

a second laser light source for outputting a second laser beam having a second wavelength at a slight angle from the first laser beam;

a nonlinear wavelength conversion device having a plurality of semiconductor materials united with each other by diffused junction, the plurality of semiconductor materials having a length in a direction coaxial with the optical axes of the first and second laser beams, and having a polarization direction arranged in parallel and alternately inverted; and

an output beam generated from the nonlinear wavelength conversion device and corresponding to a difference frequency between the first laser beam and the second laser beam, the difference frequency in a terahertz band, wherein said output beam is coaxial with the direction of the plurality of semiconductor materials.

16. A solid-state light source apparatus according to claim 15, wherein the first wavelength of the first laser beam is shorter than the second wavelength of the second laser beam.

17. A solid-state light source apparatus according to claim 15, wherein the first wavelength of the first laser beam is longer than the second wavelength of the second laser beam.