Large tolerance fiber optic transmitter and receiver
View Patent ↗An optical transmitter relaxes the tolerance between a source assembly and a fiber receptacle to facilitate passive alignment. The source assembly includes a light source and a lens. The lens is held at a fixed distance away from the light source using precise support structures typically formed by photolithographic processes. The fiber receptacle includes an optical element. The fiber receptacle is adapted to hold an optical fiber at a fixed distance from the optical element. The lens substantially collimates light from the light source into the form of collimated light. The optical element focuses the collimated light onto the aperture of the optical fiber.
1. An optical coupling system, comprising:
a plurality of light sources formed in a substrate;
a plurality of support structures photolithographically formed on the substrate;
a plurality of first lenses attached to the support structures, each first lens substantially collimating light from a corresponding light source, each first lens being fixed at a first distance from a corresponding light source by a corresponding support structure; and
a fiber receptacle comprising a plurality of second lenses and a plurality of ports for receiving a plurality of fiber connectors, each port positioning a corresponding fiber connector at a second distance from a corresponding second lens, each second lens focusing substantially collimated light from a corresponding first lens onto a corresponding optical fiber in a corresponding fiber connector.
2. An optical coupling system as in claim 1 , wherein each of the support structures includes a standoff for supporting the first lens.
3. An optical coupling system as in claim 2 , wherein each of the first lenses is a ball lens having a first focal length, the ball lens being substantially spherical.
4. An optical coupling system as in claim 3 , wherein each of the second lenses comprises a lens surface having a second focal length.
5. An optical coupling system as in claim 4 , wherein the first distance is substantially equal to the first focal length of the ball lens.
6. An optical coupling system as in claim 5 , wherein the second distance is substantially equal to the second focal length of the lens surface.
7. An optical coupling system as in claim 6 , wherein each of the light sources is a vertical cavity surface emitting laser (VCSEL).