Low-voltage quantum well microring-enhanced Mach-Zehnder modulator

Abstract

Modulation characteristics of a novel InGaAs/InAlAs multiple quantum well (MQW) microring-enhanced Mach-Zehnder modulator (MRE-MZM) is investigated in detail and its low-voltage operation with high extinction ratio is demonstrated. The MZM has a single microring resonator in one arm and is driven by the change in electrorefractive index induced by the quantum-confined Stark effect in the MQW core layer. As the MQW, a multiple five-layer asymmetric coupled quantum well (FACQW) is used to obtain a large electrorefractive index change. The driving voltage of the proposed MZM is significantly reduced owing to the enhanced phase shift in the microring resonator. High-mesa waveguide structures are grown by solid-source molecular beam epitaxy and fabricated by inductively coupled plasma etching. A directional coupler with an asymmetric branching ratio is used as an input coupler to prevent the degradation of the extinction ratio of the MZM. The extinction ratio of the fabricated MRE-MZM is approximately 27 dB. The product of the half-wave voltage and phase shifter length, V(π) · L, is 1.7 Vmm in static modulation. This value is one-quarter that of a conventional MZM with the same waveguide structure.

Characteristics of Highly Sensitive Hydrogen Sensor Based on Pt-WO3/Si Microring Resonator

“…Although we discussed the Si-MRR gas sensor in the previous sections, an MRR-enhanced Mach-Zehnder interferometer (MRR-MZI) [32][33][34] enables us to detect hydrogen with much higher sensitivity. Figure 13 shows a schematic top view of the Si-MRR-MZI sensor.…”

“…The light propagation loss in the waveguide was assumed to be 12 dB/cm. The power splitting ratio of the input MMI coupler is adjusted to obtain The MRR is a phaseshifter of the MZI and its phase shift is enhanced owing to the resonant effect in the MRR [32,33]. The phase shift enhancement factor is strongly dependent on the Q-factor of the MRR, and the Q-factor is determined by the power coupling efficiency K between the MRR and the arm waveguide.…”

32-Gbps single silicon microring resonator-loaded Mach–Zehnder modulator

“…In the vicinity of ϕ = 0, that is, in the on-resonance state, the marked nonlinearity and the single-pass phase shift are strongly enhanced. Here, we define the phase shift enhancement factor F pe as 38,39) …”

Highly sensitive optical biosensor based on silicon-microring-resonator-loaded Mach–Zehnder interferometer

“…Figure 2 shows a schematic view of an MRR coupled with a busline waveguide, where E 1 to E 4 are the optical electric fields at Ports 1 to 4, respectively. The effective phase ϕ eff , which is the difference in phase between electric fields E 1 and E 3 , is given by 30,32) eff ¼ arg…”

“…30) Owing to the combination of an MZI and the enhanced phase change in an MRR, compact and low-voltage optical modulators have been developed. [31][32][33][34][35] If an MRR-MZI is applied to biosensing, MRR-based biosensors with higher sensitivity than conventional MRR sensors can be realized.…”