Wavelength converter and two-dimensional image display device
View Patent ↗A wavelength converter of the present invention is provided with a laser resonator including a fiber containing an laser-active material and a fiber grating formed in the fiber, a laser light source for emitting an excitation light to the fiber, and a wavelength conversion element for converting a fundamental wave of a laser beam emitted from the laser resonator into a harmonic, wherein the fiber is coiled and has the outer side thereof coated with a heat radiating member having a reflection surface for reflecting light having a wavelength of an excitation light. The wavelength converter is designed to prevent an efficiency reduction caused by the heat generation of a rare-earth doped fiber in a wavelength converter.
1. A wavelength converter, comprising:
a fiber laser resonator including a fiber containing a laser-active material and a fiber grating formed in the fiber;
a laser light source for emitting an excitation light to the fiber; and
a wavelength conversion element for converting a fundamental wave of a laser beam emitted from the fiber laser resonator into a harmonic,
wherein:
the fiber containing the laser-active material is coiled; and
at least a part of the outer surface of the fiber includes a reflection surface for reflecting light having the wavelength of the excitation light and is covered by a heat radiating member that radiates heat generated by the fiber.
2. A wavelength converter according to claim 1 , wherein the heat radiating member is made of a sheet of metal.
3. A wavelength converter according to claim 1 , wherein the heat radiating member is made of metal and is coated on the outer surface of the fiber.
4. A wavelength converter according to claim 3 , further comprising:
a pair of resin films bonded to each other by compression; and
a heat transfer sheet;
wherein the heat radiating member coated on the fiber is accommodated between the pair of resin films and is held on the heat transfer sheet.
5. A wavelength converter according to claim 4 , wherein a part of the heat transfer sheet is arranged outside the pair of resin films.
6. A wavelength converter according to claim 5 , further comprising a heat sink provided in a part of the heat transfer sheet arranged outside the pair of resin films.
7. A wavelength converter according to claim 1 , further comprising:
a pair of resin films bonded to each other by compression; and
a heat transfer sheet;
wherein the fiber is accommodated between the pair of resin films and is held on the heat transfer sheet.
8. A wavelength converter according to claim 7 , wherein a part of the heat transfer sheet is arranged outside the pair of resin films.
9. A wavelength converter according to claim 8 , further comprising a heat sink provided in a part of the heat transfer sheet arranged outside the pair of resin films.
10. A wavelength converter according to claim 7 , wherein the heat transfer sheet is made of layered graphite.
11. A wavelength converter according to claim 7 , wherein the heat transfer sheet has a groove, and the fiber includes a coiled part which is accommodated between the resin films and which is arranged in the groove.
12. A wavelength converter according to claim 1 , wherein:
the fiber has a cladding diameter from 120 μm (inclusive) to 130 μm (inclusive) and a core diameter of 12 μm or shorter.
13. A wavelength converter according to claim 1 , wherein:
the fiber has a cladding diameter from 120 μm (inclusive) to 130 μm (inclusive) and a core diameter of 10 μm or shorter; and
the fiber is coiled to have a diameter of 10 cm or shorter.
14. A wavelength converter according to claim 1 , wherein the fiber contains Yb ions or Nd ions as the laser-active material.
15. A wavelength converter according to claim 1 , wherein:
an oscillation wavelength of the laser light source is 900 nm (inclusive) to 980 nm (inclusive); and
the heat radiating member is made of metal containing aluminum or gold.
16. A wavelength converter according to claim 1 , wherein:
an oscillation wavelength of the laser light source is 450 nm (inclusive) to 980 nm (inclusive); and
the heat radiating member is made of metal containing aluminum.
17. A wavelength converter according to claim 1 , wherein:
the fiber includes a core, a cladding provided on the outer side of the core and a coating film provided on the outer side of the cladding; and
the heat radiating member is provided on the outer side of the coating film.
18. A wavelength converter according to claim 1 , further comprising a temperature compensating mechanism for suppressing a dimensional change of the fiber in longitudinal, direction result from a temperature change, wherein the temperature compensating mechanism is located at a position corresponding to the fiber grating.
19. A 2D image display device, comprising:
the wavelength converter according to claim 1 ;
a mechanism for controlling a light quantity in accordance with luminance information of an inputted video signal, and controlling an average light quantity by applying a Pulse Width Modulation (PWM) control to a light source.