Monolithically integrated 40-channel AWG filter with a 40-photodiode array on indium phosphide substrate
measuring only 6 mm by 8 mm. This was fabricated using ion implantation QWI process.

2. QWI enables 2D freedom in Bandgap Engineering

Because bandgaps can be fine tuned at any selected regions of the QW structure, the QWI technique gives complete 2 dimensional freedom in bandgap engineering. This opens up tremendous design possibilities in photonic integrated circuits. QWI fabrications may allow a photonic IC designer to layout optical functions in a 2 dimensional manner much like an integrated circuit designer in the electronic domain. Through this technique, it is conceivable to manufacture different active and passive regions in various geometric configurations on a single wafer creating densely function-packed PICs!






By creating different bandgap energies in neighboring cells via QWI,
the different active regions are able to lase at different wavelengths, creating a multiple wavelength laser array.





Quantum well intermixing was used to engineer the bandgap of the AWG filter to be transparent,
while the broadband photodetector array converts light energy into electrical energy.





Quantum well intermixing is able to monolithically integrate a DFB laser and an electro absorption modulator by
adjusting the bandgap energies of the 2 regions on the wafer. The DFB section has bandgap energy close to
photonic range, while the EA Modulator section has higher bandgap energy at zero bias.

3. QWI enables efficient PIC supply chains

DenseLight envisions the day when the the design of photonic integrated circuits can be composed on a set of common photonic devices such as laser sources, SOAs (semiconductor optical amplifiers), demultiplexing filters, electro-absorption modulators, photodetectors, passive waveguides and couplers. These devices are characterized and standardized as a set of photonic device design libraries.

A photonic foundry firm should be able to take such a design and manufacture it in mass volumes. This model ultimately points the way to an outsourced photonic supply chain where it is feasible for firms to segregate design, manufacture and distribution activities reducing the need for vertically integrated firms. With such segregation, outsourcing is possible, yielding benefits from economies of specialization in design firms and economies of scale in foundry firms. Hence, better and cheaper photonic components will eventually empower optical networks.