Embedded Rings (ER) have been fabricated on InGaAsP/InP multi-quantum wells (MQW) using electron beam lithography and methane + hydrogen reactive ion etching through Cr/SiO2 etched mask. The ER showed a spectrum with interfering resonance modes which has been positively compared with simulation. The device has been used to demonstrate low speed nonlinear tuning of 2 nm with 10 mW input optical power.
Viswas Sadasivan and Das, U., “Nonlinear tuning in InGaAsP Embedded Rings”, Optical and Quantum Electronics, vol. 50, no. 2, p. 76, 2018.