Thin laser package for optical applications
An optical projection system includes: a laser emitter configured to emit a beam along an emission axis; an optical element having an optical axis non-parallel to the emission axis, the optical element having a back focal length; and a folding optic configured to redirect the beam toward the optical axis, the beam following a folded optical path having: a first section along the emission axis from the laser emitter to the folding optic; and a second section along the optical axis from the folding optic to the optical element, the sum of the lengths of the first and second sections being equal to the back focal length, the length of the first section being a function of a divergence of the beam and the back focal length, and the folding optic having a height along the optical axis configured to redirect substantially the entire beam emitted by the laser emitter.
1. An optical projection system comprising:
a laser emitter configured to emit a beam of light along an emission axis, the beam having a divergence;
an optical element having an optical axis, the optical axis being non-parallel to the emission axis, the optical element having a back focal length; and
a folding optic configured to redirect the beam emitted by the laser emitter toward the optical axis of the optical element, the beam following a folded optical path having:
a first section extending along the emission axis from the laser emitter to the folding optic; and
a second section extending along the optical axis from the folding optic to the optical element,
the sum of the lengths of the first and second sections being equal to the back focal length,
the length of the first section being a function of the divergence of the beam and the back focal length of the optical element, the function being designed to reduce the height of the folding optic, and
the folding optic having a height along the optical axis configured to redirect substantially the entire beam emitted by the laser emitter.
2. The optical projection system of claim 1 , wherein a thickness of the optical projection system along the optical axis is independent of optical characteristics of the optical element.
3. The optical projection system of claim 2 , wherein the thickness of the optical projection system is less than 3 mm.
4. The optical projection system of claim 3 , wherein the divergence is in a range of 16 degrees to 20 degrees, and
wherein the back focal length is in a range of 3 mm to 5 mm.
5. The optical projection system of claim 1 , wherein the laser emitter is mounted on a submount, the submount raising a height of laser emitter along a direction of the optical axis, and
wherein an active area of the laser emitter faces the submount.
6. The optical projection system of claim 1 , wherein the emission axis is perpendicular to the optical axis.
7. The optical projection system of claim 1 , wherein the folding optic is a mirror.
8. The optical projection system of claim 1 , wherein the folding optic is a prism.
9. The optical projection system of claim 1 , wherein the optical element comprises a diffractive optical element.
10. The optical projection system of claim 9 , wherein the diffractive optical element is configured to perform a collimation function.
11. The optical projection system of claim 9 , wherein the diffractive optical element is configured to perform a collimation function and a patterning function.
12. The optical projection system of claim 1 , wherein the optical element comprises a light diffuser.
13. The optical projection system of claim 1 , wherein the optical element comprises a refractive lens.
14. The optical projection system of claim 1 , wherein the laser emitter and the folding optic are mounted on a substrate, the substrate having an airflow port in an optically inactive region of the substrate.
15. An optical projection system configured to emit light along an optical axis toward an optical element at a configured location, the optical element having a back focal length and being aligned with the optical axis, the optical projection system comprising:
a laser emitter configured to emit a beam of light along an emission axis, the beam having a divergence; the emission axis being non-parallel to the optical axis; and
a folding optic configured to redirect the beam emitted by the laser emitter toward the optical axis,
the optical projection system being configured to transmit the beam along a folded optical path having:
a first section extending along the emission axis from the laser emitter to the folding optic; and
a second section extending along the optical axis from the folding optic to the configured location of the optical element,
the sum of the lengths of the first and second sections being equal to the back focal length,
the length of the first section being a function of the divergence of the beam and the back focal length of the optical element, the function being designed to reduce the height of the folding optic, and
the folding optic having a height along the optical axis configured to redirect substantially the entire beam emitted by the laser emitter.
16. The optical projection system of claim 15 , wherein a thickness of the optical projection system along the optical axis, from the folding optic to the configured location, is independent of optical characteristics of the optical element.
17. The optical projection system of claim 16 , wherein the thickness of the optical projection system, from the folding optic to the configured location, is less than 3 mm.
18. The optical projection system of claim 17 , wherein the divergence is in a range of 16 degrees to 20 degrees, and
wherein the back focal length is in a range of 3 mm to 5 mm.
19. The optical projection system of claim 15 , wherein the optical element comprises a diffractive optical element.
20. The optical projection system of claim 19 , wherein the diffractive optical element is configured to perform a collimation function.