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Abstract With success of silicon photonics having mature to foundry-readiness, the intrinsic limitations of the weak electro-optic effects in Silicon limit further device development. To overcome this, heterogeneous integration of emerging electrooptic materials into Si or SiN platforms are a promising path to deliver <1fJ/bit device-level efficiency, 50+Ghz fast switching, and <10's um^2 compact footprints. Graphene's Pauli blocking enables intriguing opportunities for device performance to include broadband absorption, unity-strong index modulation, low contact resistance. Similarly, ITO has shown ENZ behavior, and tunability for EOMs or EAMs. Here we review recent modulator advances all heterogeneously integrated on Si or SiN such as a) a DBR-enabled photonic 60 GHz graphene EAM, b) a hybrid plasmon graphene EAM of 100aJ/bit efficiency, d) the first ITO- based MZI showing a VpL = 0.52 V-mm, and e) a plasmonic ITO MZI with a record low VpL = 11 V- um. We conclude by discussing modulator scaling laws for a roadmap to achieve 10's aJ/bit devices.
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Miniature, highly sensitive MOSCAP ring modulators in co-optimized electronic-photonic CMOS
Convergence of high-performance silicon photonics and electronics, monolithically integrated in state-of-the-art CMOS platforms, is the holy grail for enabling the ultimate efficiencies, performance, and scaling of electronic-photonic systems-on-chip. It requires the emergence of platforms that combine state-of-the-art RF transistors with optimized silicon photonics, and a generation of photonic device technology with ultralow energies, increased operating spectrum, and the elimination of power-hungry thermal tuning. In this paper, in a co-optimized monolithic electronics-photonics platform (GlobalFoundries 45CLO), we turn the metal-oxide-semiconductor (MOS) field-effect transistor’s basic structure into a novel, highly efficient MOS capacitor ring modulator. It has the smallest ring cavity (1.5 μm radius), largest corresponding spur-free free spectral range ( FSR = 8.5 THz ), and record 30 GHz/V shift efficiency in the O-band among silicon modulators demonstrated to date. With 1 V pp RF drive, we show an open optical eye while electro-optically tuning the modulator to track over 400 pm (69 GHz) change in the laser wavelength (using 2.5 V DC range). A 90 GHz maximum electro-optic resonance shift is demonstrated with under 40 nW of power, providing a strong nonthermal tuning mechanism in a CMOS photonics platform. The modulator has a separately optimized body layer but shares the gate device layer and the gate oxide with 45 nm transistors, while meeting all CMOS manufacturability design rules. This type of convergent evolution of electronics and photonics may be the future of platforms for high-performance systems-on-chip.
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- Award ID(s):
- 2023751
- PAR ID:
- 10354876
- Date Published:
- Journal Name:
- Photonics Research
- Volume:
- 10
- Issue:
- 1
- ISSN:
- 2327-9125
- Page Range / eLocation ID:
- A1
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1364/PRJ.438047
