Carrier-depletion based silicon modulators with lateral and interdigitated PN junctions are compared systematically on the same fabrication platform. The interdigitated diode is shown to outperform the lateral diode in achieving a low VπLπ of 0.62 V∙cm with comparable propagation loss at the expense of a higher depletion capacitance. The low VπLπ of the interdigitated PN junction is employed to demonstrate 10 Gbit/s modulation with 7.5 dB extinction ration from a 500 µm long device whose static insertion loss is 2.8 dB. In addition, up to 40 Gbit/s modulation is demonstrated for a 3 mm long device comprising a lateral diode and a co-designed traveling wave electrode.

Abstract-Silicon nitride is a promising high-index material for dense photonic circuits and applications in the visiblemidinfrared wavelength regime. Design, fabrication, and optical characterization of silicon nitride waveguides at visible-nearinfrared wavelength are presented. Finally, design and experimental results are presented for the first time for linear and focused grating couplers (GCs) at near-infrared wavelength (900 nm) for plasma-enhanced chemical vapor deposition silicon nitride wires (220 × 500 nm) and compared with theoretical simulations. An experimental efficiency of 5.7 and 6.5 dB and 1-dB bandwidth of 26 and 40 nm are reported for the linear and focused GCs, respectively.

Received Month X, XXXX; revised Month X, XXXX; accepted Month X, XXXX; posted Month X, XXXX (Doc. ID XXXXX); published Month X, XXXX Defect mediated sub-bandgap absorption is observed in ion-implanted silicon-on-oxide waveguides which experience a rapid thermal annealing at 1075 ºC. With this effect, general carrier-depletion silicon modulators exhibit the capability for optical power monitoring. Responsivity is measured to be 22 mA/W at -7.1 V bias voltage for a 3 mm long Mach-Zehnder modulator of 2×10 18 cm -3 doping concentration, and 5.9 mA/W at -10 V bias voltage for a ring modulator of 1×10 18 cm -3 doping concentration. The latter is used to demonstrate data detection of up to 35 Gbit/s.

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Abstract-Optical beam steering can find applications in several domains such as laser scanning, LiDAR (Light Detection And Ranging), wireless data transfer and optical switches and interconnects. As present beam steering approaches use mechanical motion such as moving mirrors or MEMS (MicroElectroMechanical Systems) or molecular movement using liquid crystals, they are usually limited in speed and/or performance. Therefore we have studied the possibilities of the integrated silicon photonics platform in beam steering applications. In this paper, we have investigated a 16 element one-dimensional optical phased array on silicon-on-insulator with a field-of-view of 23• . Using thermooptic phase tuners, we have shown beam steering over the complete field-of-view. By programming the phase tuners as a lens, we have also shown the focusing capabilities of this onedimensional optical phased array. The field-of-view can easily be increased by decreasing the width of the waveguides. This clearly shows the potential of silicon photonics in beam steering and scanning applications.

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We report on the fabrication of free-standing and optically active microdisks with cadmium-based colloidal quantum dots embedded directly into silicon nitride. We show that the process optimization results in low-loss silicon nitride microdisks. The Si3N4 matrix provides the stability necessary to preserve the optical properties of the quantum dots and observe efficient coupling of the photoluminescence to the resonating microdisk modes. Using a spectrally and spatially resolved microphotoluminescence measurement, we map the emission pattern from the microdisk. This technique allows us to identify the resonant modes. The results show good agreement with numerical mode simulations.

Electron beam patterning is an important technology in the fabrication of miniaturized photonic devices. The fabrication process conventionally involves the use of radiation sensitive polymer-based solutions (called resists). We propose to replace typical polymer resists with eco-friendly solvent-free room temperature ionic liquids (RTILs), which are polymerized in situ and solidified by an electron beam. It is demonstrated that the shapes of polymerized structures are different for high-viscous Cl-based RTILs and low-viscous NTf-based RTILs. Due to the the satisfactory quality of the polymerized spatial microstructures and their light transmission properties, the RTIL-derived microstructures are potentially attractive as photonic elements for near-infrared.