Optical receiver package
View Patent ↗A sub-assembly or package for a die in the receiving section of an optical transceiver includes a semiconductor sub-mount that is electrically connected to the die and a cap that is bonded to the sub-mount to hermetically seal the die in a cavity. The die can be flip-chip bonded to the sub-mount and can include a diffractive optical element fabricated on a back side of the die. Active circuitry such as an amplifier for an output signal from a photosensor one the die can be integrated into the sub-mount. For an OSA, a post can be attached to the package along a path of an optical signal to the photosensor. The post facilitates alignment of an optical fiber. A flexible or rigid circuit can be soldered to external terminals of the sub-mount.
1. A device comprising:
a sub-mount;
a die including a sensor that is electrically connected to the sub-mount;
a cap attached to the sub-mount so as to form a cavity enclosing the die; and
an alignment post attached to the cap, wherein the alignment post is glued to a surface of the cap through which an optical path to the sensor passes.
2. The device of claim 1 , further comprising a sleeve having a bore sized to accommodate the alignment post at a first end of the bore and an optical fiber connector at a second end of the bore.
3. The device of claim 1 , wherein the die is attached to the sub-mount so that a front face of the die is adjacent to the sub-mount.
4. The device of claim 3 , further comprising a lens formed on a back face of the die, the lens focusing on a photosensitive area of the sensor.
5. The device of claim 1 , farther comprising a lens integrated into the cap between the alignment post and the photosensor.
6. The device of claim 1 , wherein the sub-mount incorporates an active circuit that operates on an electrical output signal of the sensor.
7. The device of claim 6 , wherein the active circuit comprises an amplifier.
8. The device of claim 1 , wherein the cavity enclosing the die is hermetically sealed.
9. The device of claim 1 , wherein the sub-mount comprises:
internal terminals that are within the cavity and electrically connected to the die; and
external terminals that are accessible outside the cavity and are electrically connected to the internal terminals.
10. The device of claim 9 , further comprising a flexible circuit connected to the external terminals.
11. A device comprising:
a sub-mount;
a die including a sensor having a photosensitive area at a front face of the die, the die being attached to the sub-mount so that the front face of the die is adjacent to the sub-mount;
a cap attached to the sub-mount so as to form a cavity enclosing the die, the cap permitting transmission of an optical signal into the cavity; and
a lens on a back face of the die, the lens focusing the optical signal onto the photosensitive area of the sensor.
12. The device of claim 11 , further comprising a post attached to the cap along an optical path to the photosensitive area of the sensor.
13. The device of claim 12 , further comprising a sleeve having a bore sized to accommodate the alignment post at a first end of the bore and an optical fiber connector at a second end of the bore.
14. The device of claim 11 , wherein the sub-mount incorporates an active circuit that operates on an electrical output signal of the sensor.
15. The device of claim 14 , wherein the active circuit comprises an amplifier.
16. The device of claim 11 , wherein the cavity enclosing the die is hermetically sealed.
17. The device of claim 11 , wherein the sub-mount comprises:
internal terminals that are within the cavity and electrically connected to the die; and
external terminals that accessible outside the cavity and are electrically connected to the internal terminals.
18. The device of claim 17 , further comprising a flexible circuit connected to the external terminals.
19. A device comprising:
a semiconductor sub-mount including an active circuit integrated into the semiconductor sub-mount;
a die including a photosensor that is electrically connected to the active circuit; and
a cap attached to the sub-mount so as to form a cavity enclosing the die.
20. The device of claim 19 , wherein the active circuit operates on an electrical output signal of the photosensor.
21. The device of claim 19 , wherein the active circuit comprises an amplifier.
22. The device of claim 19 , wherein the cavity enclosing the die is hermetically sealed.
23. The device of claim 19 , wherein an optical signal enters the cavity through the cap.
24. The device of claim 19 , wherein the sub-mount comprises:
internal terminals that are within the cavity and electrically connected to the die; and
external terminals that are accessible outside the cavity and electrically connected to the internal terminals.
25. The device of claim 24 , further comprising a flexible circuit connected to the external terminals.
26. The device of claim 19 , further comprising an alignment post glued to a surface of the cap, wherein an optical path to the photosensor passes through the surface to which the alignment post is glued.
27. The device of claim 26 , wherein the optical path passes through the alignment post.
28. The device of claim 1 , wherein the optical path passes through the alignment post.