Emerging applications in quantum information, microscopy, biosensing,
depth sensing, and augmented reality demand miniaturized components in
the visible (VIS) and near-infrared (NIR) spectrum with wavelengths
between 380 and 1100 nm. Foundry silicon photonics, which has been
optimized for telecommunication wavelengths, can be adapted to this
wavelength range. In this article, we review recent developments in
silicon photonics for VIS and NIR wavelengths, with a focus on
platforms, devices, and photonic circuits fabricated in foundries.
Foundries enable the creation of complex circuitry at a wafer scale.
Platforms based on silicon nitride and aluminum oxide
wave-guides compatible with complementary
metal–oxide–semiconductor (CMOS) foundries are becoming available. As
a result, highly functional photonic circuits are becoming possible.
The key challenges are low-loss waveguides, efficient input/output
coupling, sensitive detectors, and heterogeneous integration of lasers
and modulators, particularly those using lithium niobate and other
electro-optic materials. These elements, already developed for
telecommunications, require further development for λ < 1100 nm. As short-wavelength silicon
photonics technology advances, photonic integrated circuits can
address a broader scope of applications beyond O- and C-band
communication.