Layered 2D graphene oxide (go) films are integrated with micro ring resonators (MRRs), which can enhance nonlinear optics. The thickness of complementary metal oxide semiconductor (CMOS) films doped with silicon dioxide MRRs can be precisely controlled by uniformly coating (1-5 layers) and graphically (10-50 layers) go films on a large area, non transfer and layer by layer method. The graphic device further adopts photolithography and stripping process to ensure accurate control of film position and coating length. The results of four wave mixing (FWM) measurements with different pump powers and resonant wavelengths show that the efficiency of single-layer go device is significantly improved by about 7.6 dB, while that of 50 layer go device is about 10.3 dB. The measurement results are in good agreement with the theory. This is due to the high Kerr nonlinearity and low loss of go film, and the strong light mass interaction in MRRs, which improves the efficiency of FWM. The relationship between the third-order nonlinear pair number of layers of go and the pump power is analyzed from FWM measurement. The interesting physical views on the evolution of go film from 2D single layer to quasi block are revealed. These results show that the integrated cavity combined with 2D layered graphene oxide film has good nonlinear optical properties.
Figure 1. A) schematic diagram of graphene oxide coating integration MRR. b) SEM images of 2D layered go films. c) Raman spectra of go free and go integrated chips with two layers. d) Measure the thickness of go film and the number of go layers. e) Comprehensive MRR drawing of 50th floor go. f) Schematic diagram of preparation process with go film integrated MRR.
Figure 2. A, b) the integrated MRR transmission spectrum with 1-5 layers of go uniformly coated and 10-50 layers of go graphically measured by low power CW light respectively. c. D) when another high-power CW pump injected a resonance of about 1550.18 nm, the MRR transmission spectra with a uniform coating and 50 patterned go were measured by using a low-power CW probe.
Figure 3. A, b) power related extinction ratio (ERs) and C, d) quality factor (QS) of MRR with 1-5 layers of uniform coating and 10-50 layers of patterned go film, respectively. (E, f) the fitting propagation loss obtained from (a? D).
Figure 4. Experimental setup of FWM measurement in integrated MRRs.
Figure 5. A, b) for MRRs with 1-5 layers of uniform coating and 10-50 layers of patterned go film, FWM spectrum at 22 DBM pump power. c. D) ce enhancement and additional insertion loss extracted from (a) and (b). e. F) for MRRs with 1-5 layers of uniform coating and 10-50 layers of patterned go film, the relationship between CE and pump power.
Figure 6. A-C) the spectra of uncoated MRR, evenly coated go, and 50 coated go at different resonance wavelengths. d) The relationship between CE and Δλ / FSR measured by MRRs in (a? C).
Figure 7. Analyze the change of go material properties during FWM.
The related research results were published on small (DOI: 10.1002 / small. 201906563) by David J. moss research group of Swinburn University of technology in 2020. Original: 2D layered graphite oxide films integrated with micro ring resonators for enhanced nonlinear optics.