Compact optoelectronic modules
Compact optoelectronic modules are described that, in some implementations, can have reduced heights, while at the same time having very little optical crosstalk or detection of stray light. An optoelectronic module having optical channel can include a support on which is mounted an optoelectronic device arranged to emit or detect light at a particular one or more wavelengths. The module has a cover including an optically transmissive portion over the optoelectronic device. The optically transmissive portion is surrounded laterally by sections of the cover that are substantially non-transparent to the one or more wavelengths. A passive optical element is present on a surface of the optically transmissive portion. A spacer separates the support from the cover. The cover can be relatively thin so that the overall height of the module is relatively small.
1. A wafer-level fabrication method for making a plurality of optoelectronic modules, the method comprising:
providing a support wafer on which are mounted a plurality of optoelectronic devices each of which is arranged to emit or detect light at a particular one or more wavelengths;
providing an optics wafer that includes optically transmissive portions surrounded laterally by sections composed of a non-transparent PCB, polymer, or ceramic material, wherein the optics wafer includes a non-transparent coating disposed directly on a surface of the non-transparent PCB, polymer, or ceramic material, wherein the surface is parallel to the support wafer, wherein the non-transparent coating is composed of a material different from the non-transparent PCB, polymer, or ceramic material, wherein each of the transmissive portions including a respective passive optical element on its surface, and wherein a combined thickness of the coating and the non-transparent PCB, polymer, or ceramic material has a thickness in a range of 100-150 μm and the coating has a thickness of less than 20 μm; and
attaching the support to the optics wafer by way of a spacer to form a wafer stack.
2. The method of claim 1 further including separating the wafer stack into multiple optoelectronic modules each of which includes a light emitting channel and a light detecting channel.
3. The method of claim 1 wherein the coating is a metal or polymer.
4. The method of claim 1 wherein opposite surfaces of the PCB, polymer, or ceramic material include a non-transparent material coating thereon.
5. The method of claim 1 wherein the coating has a thickness in a range of 5-15 μm.
6. The method of claim 1 wherein the coating has a thickness greater than 0.5 μm.