Light transmitting modules with optical power monitoring
View Patent ↗An optical module, such as a package for a vertical cavity surface emitting laser diode (VCSEL) or other light emitting device, includes monitoring of the emitted optical power by tapping the transmitted beam. The module includes a substrate, which carries the light emitting device and an optical monitor. In addition, the module includes a transparent plate with at least two reflective regions that together redirect part of the light from the light emitting device to the optical monitor.
1. An optical assembly comprising:
an optical module comprising a housing in which a light emitting device and an optical monitor are mounted;
a multi-functional piece comprising:
a cavity to receive the optical module; and
a first reflective surface to reflect light from the light emitting device in a direction substantially perpendicular to a direction of light emitted by the light emitting device such that some of the light reflected by the first reflective surface is received by an optical component with an optical axis aligned substantially along the perpendicular direction; and
a second reflective surface to reflect some of the light from the first reflective surface to the optical monitor.
2. The optical assembly of claim 1 wherein the multi-functional piece includes a receptacle for an optical fiber ferrule to facilitate positioning of a fiber to receive at least some of the light reflected by the first reflective surface and not subsequently reflected by the second reflective surface.
3. The optical assembly of claim 1 wherein the second reflective surface is positioned to reflect light from the first reflective surface in a direction substantially perpendicular to a direction of light reflected by the first reflective surface.
4. The optical assembly of claim 3 wherein the light emitting device and the optical monitor are hermetically sealed in the optical module.
5. The optical assembly of claim 1 wherein the optical component comprises an optical fiber.
6. The optical assembly of claim 1 wherein the first reflective surface comprises a groove or facet.
7. The optical assembly of claim 6 wherein the second reflective surface comprises a groove or facet.
8. The optical assembly of claim 7 wherein the multi-functional piece is composed of plastic.
9. The optical assembly of claim 1 wherein the light emitting device is a semiconductor laser diode.