Editorial for the Special Issue on Silicon Photonics Bloom

Qiancheng Zhao, Ozdal Boyraz
2020 Micromachines  
Silicon (Si) photonics debuted in the mid-1980s through the pioneering work done by Soref et al. While early work mainly focused on waveguides, switches, and modulators, significant momentum surged around the mid-2000s when great breakthroughs were achieved in GHz Si modulators, Raman Si lasers, and germanium (Ge)-on-Si epitaxial integration. Today, 30 years later, silicon photonics has experienced tremendous growth and become the backbone of integrated photonics, evolving from single passive
more » ... mponents to hybrid functionalized architectures. Its scope is far beyond the traditional group IV elements, extending to compounds like silicon nitride, silicon oxynitride, and silicon carbon, in addition to heterogeneous integrations with III-V/II-VI elements, chalcogenide, graphene, crystals, polymers, etc. The popularity of Si photonics is partially attributed to its compatibility with the mature complementary metal-oxide-semiconductor (CMOS) technology that allows for low-cost and large-scale manufacturing. With the recent injection of government and private funding, more and more foundries, equipped with well-established and market-proven product development kits, will spring up, promoting a bloom in Si photonics in the new era. This Special Issue of Micromachines, entitled "Silicon Photonics Bloom", has 10 research papers and 2 review articles, covering the scale from material preparation [1,2], to single device design [3] [4] [5] [6] [7] , to photonic integration [8-11], to system architecture [12] . The demonstrated devices and components include source generation [1, 5, 6, 11] , modulators [7] , switches [4, 8] , gratings [3, 10] , and couplers [9, 12] and are applied to applications such as dispersion control [3], photonic memory [4], optic communication [8,10], polarization management [9], and photonic computing [12] . The spectrum of the contributed research spans a wide range, from visible [1,2,6], to telecom wavelength [3, 4, [7] [8] [9] [10] , to mid-IR [11] , to terahertz frequencies [5] . Revolutionary technology usually starts from fundamental breakthroughs, especially in materials, in which new properties prompt unprecedented discoveries and innovations. Studies on the material properties are the cornerstones of silicon photonics, not only because new materials enable novel functionalities, but also because the accuracy of the material properties directly impacts the design of the photonic devices. Song et al. [1] studied SiC x O y material, particularly on the effect of nitrogen doping on the photoluminescence of the amorphous SiC x O y films. Nitrogen doping creates defect centers in the SiC x O y bandgap. By varying the doping concentration, the defect center energy level could be adjusted, yielding photoluminescence from red to orange, as well as blue photoluminescence. Similar to the SiC x O y , the luminescent properties of the SiN x O y film are also studied in this Special Issue. In the review article [2] by Shi et al., the luminescence properties and fabrication methods of the SiN x O y films are summarized, and their applications as barrier materials in non-volatile semiconducting memory, optical devices, and anti-scratch coating are enumerated with abundant state-of-the-art examples. The review has an in-depth elaboration of the preparation of the SiN x O y film, serving as a solid reference for fabrication.
doi:10.3390/mi11070670 pmid:32664197 fatcat:tlwlomkznrcyxekemtd7lhtz2i