Optoelectronic modules including an optical system tilted with respect to a focal plane
The present disclosure describes optoelectronic modules that include an optical system tilted with respect to a focal plane. For example, an optoelectronic module can includes an optical system including a vertical alignment feature. An optoelectronic sub-assembly includes an active optoelectronic device, wherein the vertical alignment rests on a surface of the optoelectronic sub-assembly and wherein an optical axis of the optical system is tilted with respect to a focal plane in the sub-assembly.
1. A method comprising:
acquiring optical data for an optical system that includes a vertical alignment feature;
machining the vertical alignment feature based, at least in part, on the acquired optical data so as to adjust an amount by which the vertical alignment feature extends from the optical system; and
placing the optical system over an optoelectronic sub-assembly such that the vertical alignment feature rests on a surface of the optoelectronic sub-assembly and such that an optical axis of the optical system is tilted with respect to a focal plane in the optoelectronic sub-assembly, wherein placing the optical system over the optoelectronic sub-assembly includes placing the optical system such that the machined vertical alignment feature rests directly in contact with a surface of an image sensor.
2. The method of claim 1 wherein machining the vertical alignment feature includes at least one of cutting, dicing or grinding.
3. The method of claim 1 wherein the acquired optical data includes modulation transfer function versus z data of an on-axis field parameter and a plurality of off-axis field parameters, wherein the z data represents a distance from the optical system.
4. The method of claim 1 wherein placing the optical system over the optoelectronic sub-assembly includes placing the optical system such that the vertical alignment feature rests directly in contact with a surface of an illumination projector sub-assembly.
5. The method of claim 4 wherein the illumination projector sub-assembly includes a mask, and wherein placing the optical system over the optoelectronic sub-assembly includes placing the optical system such that the vertical alignment feature rests directly in contact with a surface of the mask.
6. The method of claim 1 wherein the vertical alignment feature includes an annular or semi-annular protrusion, the method including machining different parts of the protrusion so as to have heights that differ from one another.
7. The method of claim 1 wherein the vertical alignment feature includes a plurality of protrusions, the method including machining the protrusions so as to have heights that differ from one another.
8. The method of claim 1 wherein the tilt at least partially corrects for distortion asymmetry.