Bandwidth and Wavelength Tunable All-Optical Filter Based on Cascaded Opto-Mechanical Microring Resonators

Abstract

We propose and experimentally demonstrate an all-optical filter with tunable bandwidth and wavelength based on cascaded opto-mechanical microring resonators (MRRs). As the transmission of each MRR could be tuned by injecting resonance powers, the total transmission of the three cascaded MRRs could be manipulated to realize tunable all-optical filters. Due to the free-hanging waveguides of the opto-mechanical MRRs, the nonlinear effects in the device are efficiently enhanced, which contribute to reduce the resonance powers. In the experiment, the bandwidth and wavelength tunability of the optical filter have been demonstrated by injecting three resonance powers. The tuning efficiencies of the filter's 3 dB bandwidth and wavelength could reach 0.233 nm/mW and 0.043 nm/mW respectively, which benefit the construction of all-optical systems with low-power consumptions. The footprint of the compact device is 0.02 mm 2 . The proposed tunable optical filter is competent to process optical signals with dominant advantages of high tuning efficiencies, all-optical control, compact footprint, and complementary metal-oxide semiconductor-compatibility, which has significant applications for on-chip all-optical systems.

Short Carbon Nanotube Nano-Film-Based Polymer/SiO2 Hybrid Waveguide Micro-Ring Filter

“…It can be seen from the above formulas that the temperature change of the polymer waveguide will cause the change of the volume expansion coefficient and density of the polymer waveguide, which will eventually lead to a change in the RI of the waveguide. Because of the asymmetric structure of the waveguide, a polarization effect will be generated; according to the Lorentz−Lorentz equation, 21 we get (4) where Λ 0 is the strain polarization constant of the polymer waveguide and Λ 0 is far less than 1, which is the density change effect caused by the polarization of the polymer waveguide.…”

“…In 2016, Dai et al proposed an ultra-small bandwidth and wavelength-tunable micro-ring optical passband filter based on silicon chips in the case of 1 dB in-band ripple; 3 the effective tuning range and tuning efficiency were 0.6 nm (75 GHz) to 2.4 nm (300 GHz) and 0.03 nm/mW, respectively. In 2019, Liu et al proposed a high-coherent efficiency bandwidth and wavelength-tunable all-optical tunable filter based on cascaded silicon optomechanical MRRs, 4 and its wavelength tuning efficiency was 0.043 nm/ mW. However, the above-mentioned cascaded structure may easily introduce more noise and lead to more insertion loss for the filter.…”

Tunable Vernier Series-Coupled Microring Resonator Filters Based on InGaAs/InAlAs Multiple Quantum-Well Waveguide

“…Hu et al demonstrated a thermally tunable Si third-order MRR filter with a tuning efficiency of 48.4 mV/nm [20]. Liu et al employed the opto-mechanical effect in MRR tuning, and the wavelength tuning efficiency of the MRR filter reached 0.043 nm/mW [21]. However, most of the MRR filters are mainly derived from the thermo-optic (TO) effect to achieve wavelength tuning.…”

On-Chip All-Optical Tunable Filter With High Tuning Efficiency

“…The extinction ratio is 30 dB while the bandwidth and wavelength tuning efficiencies are only 0.004 nm/mW and 0.003 nm/mW, respectively. Moreover, the cascaded MRRs [23], [24] and Bragg grating couplers [25] are also used to implement tunable optical filters. However, most tuning efficiencies are still lower than 0.05 nm/mW, which limits their practical applications in optical communication systems.…”