Demonstration of DC Kerr effect induced high nonlinear susceptibility in silicon rich amorphous silicon carbide

Abstract

In this study, we demonstrate the DC Kerr effect in plasma-enhanced chemical vapor deposition silicon rich amorphous silicon carbide (a-SiC). Using the resonance shift of the transmission spectra of a ring resonator, we experimentally extract the third order nonlinear susceptibility χ3 to be 6.90×10−19 m2/V2, which is estimated to be more than six times higher than previous reported values in stoichiometric a-SiC. The corresponding induced second order nonlinear susceptibility χ2 of 44.9 pm/V is also three times higher than the reported value in silicon and silicon rich nitride utilizing the DC Kerr effect. The high nonlinearity makes silicon rich a-SiC a good materials candidate for nonlinear photonic applications.

High thermo-optic tunability in PECVD silicon-rich amorphous silicon carbide

“…Table 1 summarizes the materials index and the flow rate of precursor gases for samples SRC1, SRC2, and SRC3 investigated in this work. Energy-Dispersive X-ray spectroscopy (EDX) measurement in our previous work indicates that the silicon content increases as the SiH4/CH4 gas flow ratio increases [14]. The EDX estimated silicon content of these samples is shown in Table 1.…”

“…By tuning the deposition conditions, we can change the silicon content in the material and hence design for improved optical properties. It has already been demonstrated that very high third-order nonlinearity can be obtained in silicon-rich a-SiC through the DC Kerr effect [14]. A higher refractive index facilitates a more confined mode inside the waveguide, thus allowing a smaller device footprint.…”

Nonlinear Optical SiC:C Microring for an ASK-to-PSK Gate and NOT + XOR Logic beyond 10 Gbit/s

“…In addition, Lin and co-workers demonstrated the high- Q amorphous SiC (a-SiC) microdisk with a Q -factor of 1.3 × 10 5 and a nonlinear refractive index of (5.9 ± 0.9) × 10 –15 cm 2 /W at 1550 nm . Yu and co-workers observed the DC Kerr effect in the silicon-rich a-SiC to obtain second- and third-order nonlinear susceptibilities of 44.9 pm/V and 6.9 × 10 –19 m 2 /V, respectively . Yi’s group has used a SiC electro-optic modulator to perform 15 Gbit/s non-return-to-zero on–off keying (NRZ-OOK) modulation .…”

“…49 Yu and co-workers observed the DC Kerr effect in the silicon-rich a-SiC to obtain second-and third-order nonlinear susceptibilities of 44.9 pm/V and 6.9 × 10 −19 m 2 /V, respectively. 50 Yi's group has used a SiC electrooptic modulator to perform 15 Gbit/s non-return-to-zero on− off keying (NRZ-OOK) modulation. 51 To enhance the nonlinear Kerr effect in the waveguide, the non-stoichiometric silicon carbide (SiC x ) is considered a candidate because of its relatively larger nonlinear refractive index coefficient.…”