Parallel optical system with integrated monitoring photodetectors
The invention provides an optical system, in particular, a multi-channel parallel optical transceiver system with monitoring photodetectors and methods of forming the same. The multi-channel parallel optical system includes a substrate with at least one optical component mounted on the first side, at least one optical monitoring photodetector (mPD) fabricated on the first side of the substrate, a set of optical functional components disposed on the first side of the substrate to guide and reflect the light signal, an arrayed fiber placement structure fixing at least one optical fiber and having an exposed end to couple with the optical functional components to guide and diffract light from and to the optical components mounted on the first side of the substrate. The optical alignment of the optical placement structure, optical functional components, and the optical components mounted on the substrate is realized passively through the alignment holes and pins.
1. An optical system comprising:
a substrate having a first side;
a light emitting component mounted on the first side of the substrate for emitting a light signal;
an optical monitoring photodetector structure disposed on the first side of the substrate;
an arrayed fiber placement structure for fixing at least one optical fiber and having an exposed end that exposes an end of the at least one optical fiber; and
one set of optical functional components disposed between the arrayed fiber placement structure and the first side of the substrate, for directing a part of the light signal emitted by the light emitting component to the exposed end of the arrayed fiber placement structure and directing another part of the light signal emitted by the light emitting component to the optical monitoring photodetector structure,
wherein the one set of optical functional components comprises two single optical functional components arranged back to back, wherein a second side of each of the two single optical functional components includes a slanted surface region, and wherein the slanted surface regions of the two single optical functional components are in tight contact with each other and are disposed on an optical path of the light signal.
2. The optical system of claim 1 , wherein each of the two single optical functional components has at least one alignment hole extending through it.
3. The optical system of claim 1 , wherein the substrate has at least one alignment hole extending into it from its first side, wherein the arrayed fiber placement structure has at least one alignment pin placed through it, the at least one alignment pin being inserted into the at least one alignment holes of the one set of optical functional components and the at least one alignment hole of the substrate.
4. The optical system of claim 1 , wherein the slanted surface regions of the two single optical functional components that are in tight contact with each other form an optical surface to partially reflect the light signal back to the optical monitoring photodetector and partially transmit the light signal to the exposed end of the arrayed fiber placement structure.
5. The optical system of claim 1 , wherein the optical monitoring photodetector includes a light-responsive p-i-n diode or p-n diode including p-doped regions, n-doped regions, and regions sandwiched between the p-doped regions and the n-doped regions.
6. The optical system of claim 1 , wherein the substrate has at least one metal layer formed on its first side and electrically connected to the light emitting element mounted on its first side and the at least one optical monitoring photodetector integrated on its first side.
7. The optical system of claim 2 , wherein each one of the single optical functional components has a first side integrated with at least one optical microlens and wherein the slanted surface region of the second side of each one of the optical functional components is aligned with a center of the at least one optical microlens on the respective first side.
8. The optical system of claim 7 , wherein the slanted surface region on the second side of one of the single optical functional component has an optically smooth surface coated with a partial reflecting film.
9. The optical system of claim 7 , wherein each one of the single optical functional components has spacer structures on the first side.
10. The optical system of claim 1 , wherein the light emitting component includes an array of light emitting devices, wherein the optical monitoring photodetector structure includes an array of optical monitoring photodetectors, wherein the at least one optical fiber includes an array of optical fibers.