The idea of integrating several photonic functions – such as generating, guiding, modulating, filtering and detecting light – within single small-waveguide devices has been around for some time and continues to be an active area of research.
For some, integration carries the promise that optics will change our world much as electronic integrated circuits (ICs) have; for others, it simply offers the opportunity to make the devices that process photons smaller, less expensive or faster, thereby advancing communications, avionics or sensing.
However, researchers are considering a large number of materials and techniques, and one can’t help thinking that the entire field is quite diffuse. This dilemma was described by Giancarlo C. Righini of Italy’s National Research Council as he wrapped up a European meeting on integrated photonics: “The bottleneck of photonic integration is related to the (too) many degrees of freedom – many different materials and technologies, many different component types, many different wavelength ranges and applications. Even if it is the sign of scientific richness and broad technological knowledge, it would be important to try to focus on a few issues; e.g., by building up on a stable technological platform ….”Read more