Dpo 2024

The optical images of the devices were taken by an optical microscope (ZEISS, Axio Imager A2m). The Raman spectra were collected by a micro-zone confocal Raman system (WITec alpha 300R) under 532 nm laser illumination. The thickness of the MoTe₂ film was measured by an atomic force microscope (Asylum Research, Cypher S). All the electrical measurement was conducted in the dark with a semiconductor characterization system (Keithley 4200-SCS) that was connected to a probe station. For the dynamic switching performance measurement, a function generator (Tektronix AFG 3102) and a digital oscilloscope (Tektronix DPO 2024) were employed to generate the V_in and record the V_out, respectively. Both the function generator and the digital oscilloscope had common ground with the semiconductor characterization system, which provided the V_dd. All the characterizations were performed in ambient condition.

The group velocity dispersion (GVD) is simulated using commercial finite element analysis software (COMSOL) based on the fabricated device geometry. Anomalous GVD is achieved for both the TE and TM modes at telecommunication wavelengths (see Supplementary Information). A continuous-wave pump laser (Santec TSL-510) at 1570 nm is amplified by an L-band erbium-doped fibre amplifier (EDFA, Manlight) and sent to the microring resonator using a lensed fibre after a polarisation controller. The tuning of the laser is controlled by a piezo controller. The output is collected by an aspheric objective followed by a fibre collimator. A 90:10 fibre beamsplitter is used to separate the output light into two arms. The 10% arm is sent to an optical spectrum analyser, and the 90% arm is sent through a home-built 4-f shaper (effectively a bandpass filter, 1575–1630 nm) to filter the pump. The filtered comb spectrum is sent to a photodetector (Newport 1811, 125 MHz) and a real-time spectrum analyser (Tektronix RSA5126A). For Fig. 5c, a functional generator with a triangular function is sent to the piezo controller to scan the laser wavelength at 70 Hz, and the filtered comb is collected by a photodetector (Thorlabs, PDA05CF2) followed by an oscilloscope (Tektronix DPO2024, 200 MHz).

Table 2 shows the operating conditions for generating the plasma bubbles used in this study. Plasma was generated between two electrodes separated by an aluminum oxide plate (Figure 1A) and was injected into deionized water (400 mL) at a gas flow rate of 4 L/min through a bubbler. The specific voltage and current waveform generated from the DBD are presented in Figure 1C. Voltage and current profiles were obtained using a digital oscilloscope (DPO 2024, Tektronix, Beaverton, OR, USA) equipped with a voltage probe (P6015A, Tektronix, Beaverton, OR, USA) and current probe (Pearson 411, Pearson Electronics, Inc., Pal Alto, CA, USA).