In recent years, the 2 µm waveband has been gaining significant attention due to its potential in the realization of several key technologies, specifically, future long-haul optical communications near the 1.9 µm wavelength region. In this work, we present a hybrid silicon photonic wavelength-tunable diode laser with an operating range of 1881-1947 nm (66 nm) for the first time, providing good compatibility with the hollow-core photonic bandgap fiber and thulium-doped fiber amplifier. Room-temperature continuous-wave operation was achieved with a favorable on-chip output power of 28 mW. Stable single-mode lasing was observed with side-mode suppression ratio up to 35 dB. Besides the abovementioned potential applications, the demonstrated wavelength region will find critical purpose in H 2 O spectroscopic sensing, optical logic, signal processing as well as enabling the strong optical Kerr effect on Si.

We designed and demonstrated TE-mode arbitrary power splitters based on adiabatic mode evolution. The power splitters are designed with a footprint of smaller than 12 × 2.9 µm 2 , fabricated on a 400-nm silicon-on-insulator platform, requiring only a single etch step. The optimization process and the conditions for arbitrary-power splitting are performed using three-dimensional-FDTD simulations. We prove this concept through the fabrication of asymmetrical adiabatic evolution-based power splitters with splitting ratios of 50:50, 60:40, and 70:30. The fabricated devices are shown to agree closely with simulation results. Broadband operation with low insertion loss of 0.11-0.6 dB is demonstrated across the 3.66-3.89 µm wavelength range (230 nm). This component has applications in a multitude of areas such as spectroscopic optical sensing and optical phased arrays photonic integrated circuits etc.

Silicon photonics at the 2 μm waveband, specifically the 1.9 μm wavelength region is strategically imperative. This is due to its infrastructural compatibility (i.e., thuliumdoped fiber amplifier, hollow-core photonic bandgap fiber) in enabling communications, as well as its potential to enable a wide range of applications. While the conventional Siliconon-Insulator platform permits passive/active functionalities, it requires stringent processing due to high-index contrast. On the other hand, SiN can serve to reduce waveguiding losses via its moderate-index contrast. In this work, by demonstrating SiN passives and Si-SiN interlayer coupler with favorable performance, we extend the Si-SiN platform to the 1.9 μm wavelength region. We report waveguide propagation loss of 2.32 dB/cm. Following, trends in radiation loss with regards to bending radius is analyzed. A high performance 3-dB power splitter with insertion loss and bandwidth of 0.05 dB and 55 nm (1935-1990 nm) respectively is introduced. Lastly, Si-SiN transition loss as low as 0.04 dB is demonstrated.

The key advantage of silicon photonics comes from its potential for large scale integration, in a low-cost and scalable fashion. This has sustained the growth in the area despite disadvantages such as the lack of a monolithic light source, or the absence of a second order non-linear response (χ (2) ). Thus far, the work in the field has focused on reporting individual devices from a single die, with excellent performances. Wafer-level results, an area which has not been addressed sufficiently, is a critical aspect of silicon photonics and will provide the community with information regarding scalability and variation, which will be the key differentiating advantage of silicon photonics over other photonic platforms. In this work, we report the development of a low-loss, high-bandwidth C-band silicon photonic platform on a 200 mm CMOS-compatible process line, demonstrating wafer-level performance in the process. Ultra-low waveguide propagation loss with median values as low as 0.43 dB/cm has been achieved. Silicon Mach-Zehnder and microring modulators with median bandwidth of 38.5 and 43 GHz respectively are presented. Finally, germanium waveguide-integrated photodetectors with median bandwidth of 43 GHz are reported. The results reported in this work are comparable to prior demonstrations concerning individual devices. The baseline designs on this platform presented in this work can be accessed commercially from CompoundTek.

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