Wavelength division multiplexing receiver
AssigneeNokia Solutions and Networks Oy
InventorsJoan Manel Ramirez, Claire Besancon
Life of this patent
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Abstract
A demultiplexer-free wavelength division multiplexing receiver based on cascaded-bandgap waveguide photodiodes, includes a substrate; and a plurality of different absorbing material sections forming a plurality of independent photodetector sections, each with a different thickness and a different bandgap. The plurality of photodetector sections may be fabricated at the same time on the same substrate, whereby different widths between each pair of mask stripes results in a different thickness of each photodetector section and a different bandgap of each photodetector section. The photodetector sections are then optically connected together into concatenated photodetector sections forming a single elongated optical waveguide.
Claims17
A wavelength division multiplexor (WDM) photodetector receiver, comprising:
- cascaded-bandgap waveguide photodetector sections with multiple concatenated bandgaps, arranged from lowest wavelength to highest wavelength, based on Multiple Quantum Well (MQW) absorbing media, each photodetector section configured for a corresponding different single wavelength in bandgap and length, wherein the cascaded-bandgap waveguide photodetector sections are aligned and connected into concatenated photodetector sections forming a single elongated optical waveguide adapted for guiding an incoming signal successively through each waveguide photodetector section,
- wherein a respective minimum photodetector length is defined for absorbing a respective single wavelength, and
- at least one of the photodetector sections is configured longer than a corresponding respective minimum photodetector length for absorbing the respective corresponding different single wavelength.
A method of fabricating a wavelength division multiplexor (WDM) photodetector receiver, comprising:
- a) providing a substrate;
- b) providing a plurality of pairs of selective mask stripes with a trench therebetween on the substrate, each pair of mask stripes having a different width;
- c) providing an absorbing material in each trench forming a plurality of photodetector sections at a same time, whereby the different width of each pair of mask stripes results in a different thickness of each photodetector section and a different bandgap of each photodetector section;
- d) separating the plurality of photodetector sections;
- and
- e) connecting the plurality of photodetector sections into concatenated photodetector sections forming a single elongated optical waveguide.
Dependencies are inferred from the claim text.