Replies to post #82337 on Lightwave Logic Inc (LWLG)

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Heterogeneous integration key to future integrated-photonics growth
Paul van Gerven 16 August 2021

https://bits-chips.nl/artikel/heterogeneous-integration-key-to-future-integrated-photonics-growth/

No single integrated-photonics technology can do it all: they need to be combined for maximum functionality. The set of techniques to do that – hybrid or heterogeneous integration – is a key growth driver for the Dutch integrated-photonics industry.

In electronics, the vast majority of chips are based on silicon. Other semiconductor materials are preferred only for specialized applications. In power management chips, for example, gallium nitride is an up-and-coming substrate. But although emerging applications such as electric driving will certainly spur demand for GaN chips over the next few years, it’s unlikely they’ll ever challenge silicon’s crown in terms of number of chips manufactured or revenue generated.

The situation isn’t as clear-cut in integrated photonics. Each of the three main ‘flavors’ of this technology – indium phosphide (InP), silicon nitride (SiN) and silicon/silica photonics (SiP) – has its own strengths and weaknesses. Rather than thinking about these platforms as competing with one another, they should be considered complementary. For many applications, any one platform can’t shine without the other: they need to be combined to unlock certain functionality. Boosting performance or lowering cost can also be an incentive to making combinations.

Integration of separately manufactured components into higher-level assemblies is called hybrid or heterogeneous integration (HI). Apart from blending photonic flavors, HI is indispensable because all but the most simple photonic devices require control electronics to operate. The optical and electronic chips are manufactured in their own respective factories and then connected, assembled and packaged together into one module.

As the integrated-photonics industry matures, photonic devices will perform increasingly complex tasks. This will likely involve assembling a growing number of components, using increasingly sophisticated HI techniques. These components aren’t just photonic integrated circuits (PICs) and control chips but other (discrete) components as well. Eventually, more ‘exotic’ devices such as MEMS and (bio)sensors will make their way in there....