Bonded tunable VCSEL with bi-directional actuation
A MEMS tunable VCSEL includes a membrane device having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity. A VCSEL device includes an active region for amplifying light. Then, a proximal-side electrostatic cavity is defined between the VCSEL device and the membrane device is used to displace the mirror to decrease a size of an optical cavity.
1. A tunable vertical cavity surface emitting laser (VCSEL), comprising:
a VCSEL device including an active region for amplifying light; and
a membrane device, bonded to the VCSEL, device, having a mirror and a distal-side electrostatic cavity for displacing the mirror to increase a size of an optical cavity; and
wherein a proximal-side electrostatic cavity is defined between the VCSEL device and the membrane device for displacing the mirror to decrease a size of the optical cavity.
2. The VCSEL as claimed in claim 1 , wherein the membrane device includes metal bonded to the VCSEL.
3. The VCSEL as claimed in claim 1 , wherein the proximal-side electrostatic cavity is defined between a membrane structure of the membrane device and a proximal-side electrostatic cavity electrode metal layer on the VCSEL device.
4. The VCSEL as claimed in claim 3 , wherein a wire bond pad on the membrane device is electrically connected to the proximal-side electrostatic cavity electrode metal layer.
5. The VCSEL as claimed in claim 3 , wherein the membrane structure is doped for increased conductivity.
6. The VCSEL as claimed in claim 1 , wherein the VCSEL is protected against damage due to electrical overstress of the proximal-side electrostatic cavity by ensuring that a gap in the proximal-side electrostatic cavity is prevented from going to 0 by use of an insulating stand-off.
7. The VCSEL as claimed in claim 6 , wherein the insulating stand-off is a high reflective dielectric coating.
8. The VCSEL as claimed in claim 1 , further comprising a distal-side electrostatic cavity driver for applying a voltage to the membrane device, and a proximal-side electrostatic cavity driver for applying a voltage to the VCSEL device.
9. The VCSEL as claimed in claim 8 , further comprising wire bond pads on the membrane device to which the distal-side electrostatic cavity driver and the proximal-side electrostatic cavity driver connect.
10. The VCSEL as claimed in claim 1 , further comprising using a distal-side electrostatic cavity driver for applying a voltage across the distal-side electrostatic cavity and a proximal-side electrostatic cavity driver for applying a voltage across the proximal-side electrostatic cavity.
11. A method of operation of a tunable vertical cavity surface emitting laser (VCSEL), the method comprising:
amplifying light in an active region of a VCSEL device;
defining an optical cavity for the light between a mirror layer of the VCSEL device and a mirror of a membrane device;
using a distal-side electrostatic cavity to displace the mirror to increase a size of the optical cavity; and
using a proximal-side electrostatic cavity to displace the mirror to decrease a size of the optical cavity.
12. The method as claimed in claim 11 , wherein the membrane device includes metal bonded to the VCSEL.
13. The method as claimed in claim 11 , wherein the proximal-side electrostatic cavity is defined between a membrane structure of the membrane device and the VCSEL device.
14. The method as claimed in claim 13 , further comprising electrically connecting to the VCSEL, device by wire bonding to a wire bond pad on the membrane device.
15. The method as claimed in claim 11 , wherein the proximal-side electrostatic cavity is defined between a membrane structure of the membrane device and a proximal-side electrostatic cavity electrode metal layer on the VCSEL device.
16. The method as claimed in claim 13 , wherein the membrane structure is doped for increased conductivity.
17. The method as claimed in claim 11 , wherein the VCSEL is protected against damage due to electrical overstress of the proximal-side electrostatic cavity by ensuring that a gap in the proximal-side electrostatic cavity is prevented from going to 0 by use of an insulating stand-off.
18. The method as claimed in claim 17 , wherein the insulating stand-off is a high reflective dielectric coating.
19. The method as claimed in claim 11 , further comprising using a distal-side electrostatic cavity driver for applying a voltage to the membrane device, and a proximal-side electrostatic cavity driver for applying a voltage to the VCSEL device.
20. The method as claimed in claim 19 , further comprising connecting the distal-side electrostatic cavity driver and the proximal-side electrostatic cavity driver to wire bond pads on the membrane device.
21. The method as claimed in claim 11 , further comprising using a distal-side electrostatic cavity driver for applying a voltage across the distal-side electrostatic cavity and a proximal-side electrostatic cavity driver for applying a voltage across the proximal-side electrostatic cavity.