Speckle reduction laser and laser display apparatus having the same
A speckle reduction laser and a laser display apparatus having the speckle reduction laser are provided. The speckle reduction laser includes a semiconductor unit that comprises an active layer and emits laser light through a first side surface thereof by resonating light generated from the active layer, and a vibration mirror unit disposed adjacent to a second side surface of the semiconductor unit. The laser further includes a mirror, and the resonance of the laser light is generated between the first side surface of the semiconductor unit and the mirror, and a resonance mode of the laser light is changed according to the vibration of the mirror.
1. A speckle reduction laser comprising:
a semiconductor unit that comprises an active layer and emits laser light through a first side surface thereof by resonating light generated from the active layer; and
a vibration mirror unit, disposed at a second side surface of the semiconductor unit, and comprising a mirror,
wherein a resonance of the laser light is generated between the first side surface of the semiconductor unit and the mirror, and a resonance mode of the laser light is changed according to a vibration of the mirror.
2. The speckle reduction laser of claim 1 , further comprising an antireflective member provided on the second side surface of the semiconductor unit.
3. The speckle reduction laser of claim 1 , wherein the semiconductor unit further comprises a half mirror disposed on the first side surface, wherein the laser light is emitted through the half mirror.
4. The speckle reduction laser of claim 1 , wherein a variation width of the resonance mode of the laser light is equal to or smaller than a resonance modes spacing when the resonance mode is viewed in a frequency spectrum.
5. The speckle reduction laser of claim 1 , wherein the semiconductor unit has a limited resonance region defined by a ridge structure on the active layer.
6. The speckle reduction laser of claim 1 , wherein the vibration mirror unit comprises a vibrator on which the mirror is attached.
7. A laser display apparatus that displays an image by scanning laser light on a screen, the apparatus comprising:
a laser lighting system comprising a speckle reduction laser that comprises:
a semiconductor unit that comprises an active layer and that emits laser light through a first side surface thereof by resonating light generated from the active layer; and
a vibration mirror unit disposed at a second side surface of the semiconductor unit and comprising a mirror,
wherein a resonance of the laser light is generated between the first side surface of the semiconductor unit and the mirror, and a resonance mode of the laser light is changed according to a vibration of the mirror.
8. The laser display apparatus of claim 7 , further comprising a reflection preventive member provided disposed on the second side surface of the semiconductor unit.
9. The laser display apparatus of claim 7 , wherein the speckle reduction laser further comprises a half mirror provided on the first side surface of the semiconductor unit, wherein the laser light is emitted through the half mirror.
10. The laser display apparatus of claim 7 , wherein a variation width of a resonance mode of the laser light is equal to or smaller than a resonance modes spacing when the resonance mode is viewed in a spectrum.
11. The laser display apparatus of claim 7 , wherein the semiconductor unit has a limited resonance region defined by a ridge structure on the active layer.
12. The laser display apparatus if claim 7 , wherein the vibration mirror unit comprises a vibrator on which the mirror is attached.
13. The laser display apparatus of claim 7 , a vibration frequency of the vibration mirror unit is equal to or greater than a pixel frequency of an image displayed by the laser display apparatus.
14. The laser display apparatus of claim 7 , further comprising:
an image forming device that forms an image corresponding to an image signal input from laser light emitted from the laser lighting system; and
a projection optical system that enlarges and projects an image, formed in the image forming device, onto a screen.
15. The laser display apparatus of claim 7 , further comprising a scan system that forms an image by scanning the laser light emitted from the laser lighting system onto the screen.
16. The laser display apparatus of claim 15 , wherein the scan system comprises a two-dimensional optical scanner that scans a beam emitted from the laser lighting system in horizontal and vertical directions.
17. The laser display apparatus of claim 15 , wherein the scan system comprises:
a beam shaper that shapes incident light so that a cross-sectional shape of light emitted from the laser lighting system has a linear shape;
a line panel that modulates light shaped by the beam shaper in response to an image signal; and
a one-dimensional optical scanner that scans light emitted from the laser lighting system in a direction perpendicular to a lengthwise direction of the line panel after modulating the light in response to an image signal.