Method and system for providing directional light sources with broad spectrum
A system and method for providing laser diodes with broad spectrum is described. GaN-based laser diodes with broad or multi-peaked spectral output operating are obtained in various configurations by having a single laser diode device generating multiple-peak spectral outputs, operate in superluminescene mode, or by use of an RF source and/or a feedback signal. In some other embodiments, multi-peak outputs are achieved by having multiple laser devices output different lasers at different wavelengths.
1. An apparatus comprising:
an optical device comprising:
a gallium and nitrogen containing surface having a first crystalline surface region orientation;
an active region comprising at least one quantum well and at least one barrier layer;
a first cavity member overlaying the active region, the first cavity member having a length of at least 100 um, a width of at least 0.5 um, and being configured to emit laser light with a spectral width of at least 0.5 nm;
a source electrically coupled to the active region for providing modulation, the modulation being configured to induce spectral broadening and increase the spectral width to at least 1.5 nm; and
a lens coupled to the optical device.
2. The apparatus of claim 1 further comprising a second cavity member.
3. The apparatus of claim 1 wherein the modulation is RF modulation, and the spectral width after RF modulation is at least 3 nm.
4. The apparatus of claim 1 wherein the first crystalline surface region orientation comprises a semipolar plane such as {20-21}, {30-31}, {20-2-1}, {30-3-1}, or {11-22}.
5. A laser display or laser TV using the apparatus of claim 1 as the optical device.
6. The apparatus of claim 1 wherein the laser light is blue or green light.
7. An apparatus comprising:
an optical device having a plurality of laset diodes, at least one of the plurality of laser diodes comprising:
a gallium and nitrogen containing surface having a first crystalline surface region orientation;
an active region comprising at least one quantum well and at least one barrier layer;
a first cavity member overlaying the active region, the first cavity member having a length of at least 100 um, a width of at least 0.5 um, and being configured to emit laser light with a spectral width of at least 0.5 nm;
a source electrically coupled to the active region for providing modulation, the modulation being configured to induce spectral broadening and increase the spectral width to at least 1.5 nm; and
a lens coupled to the optical device.
8. The apparatus of claim 7 further comprising a second cavity member, wherein the first crystalline surface region orientation is either non-polar or semi-polar.
9. The apparatus of claim 7 wherein the modulation is RF modulation, and the spectral width after RF modulation is at least 3 nm.
10. The apparatus of claim 7 wherein the first crystalline surface region orientation comprises a semipolar plane such as {20-21}, {30-31}, {20-2-1}, {30-3-1}, or {11-22}.
11. A laser display or laser TV using the apparatus of claim 7 as the optical device.
12. The apparatus of claim 7 wherein the laser light is blue or green light.
13. The apparatus of claim 7 wherein the first crystalline surface region orientation is either non-polar or semi-polar.
14. The apparatus of claim 7 wherein the active region comprises at least the quantum well or double hetereostructure emitting layer and a barrier layer.
15. The apparatus of claim 7 wherein the first cavity member is characterized by a length along a c-plane, the first cavity member being configured to emit laser characterized by a spectral width of at least 1 nm.
16. The apparatus of claim 7 wherein the first cavity member functions as a waveguide.
17. The apparatus of claim 7 further comprising an optical feedback signal source coupled to the active region for inducing mode hopping.
18. The apparatus of claim 7 wherein the at least one of the plurality of laser diodes is configured to emit a multiple peak wavelength obtained by utilizing light generated in the laser diode or by an adjacent light emitting device to provide optical feedback and induce mode hopping.
19. A method for operating an optical device in an apparatus comprising:
providing an apparatus comprising a laser device comprising a gallium and nitrogen containing surface including a first crystalline surface region orientation, an active region comprising at least one quantum well and at least one barrier layer; and a first cavity member overlaying the active region, the first cavity member having a length of at least 100 um, a width of at least 0.5 um, and being configured to emit laser light with a spectral width of at least 0.5 nm;
inducing spectral broadening using a source electrically coupled to the active region for providing modulation, the modulation being configured to induce the spectral broadening and increase the spectral width to at least 1.5 nm; and
coupling the emitted laser light with a lens.
20. The method of claim 19 wherein the laser device is configured to emit a multiple peak wavelength obtained by utilizing light generated in the laser diode or by an adjacent light emitting device to provide optical feedback and induce mode hopping.