Parameters-Insensitive Modulator for Optical Interconnect Systems Based on Double Injection

A racetrack-shaped ring modulator based on Double Injection (DI) was recently reported. It is capable of delivering a variety of transform functions, and can be designed to exhibit considerably less sensitivity to deviations in parameters. The modulator is referred to as PIR20 - Parameters-Insensitive Response with a minimum extinction ratio of 20dB. The unique properties of the DI approach can override the impact of such deviations so as to obtain an extinction ratio of at least 20dB, which compares favorably with other device architectures. Such deviations may result from fabrication variations and influence sensitive components of the circuit such as coupling structures. In addition, in some architectures, e.g. Silicon Photonics, electro-optical activity generates heat due to carrier transport, which affects the circuit operation. The sensitivity of the PIR20 modulator to deviations in directional couplers and changes in temperature is analyzed and compared to other known modulators based on either a ring, MZI or Fabry-Pérot resonators. The analysis is carried out for Silicon Photonics and reveals that the PIR20 is considerably more robust to both effects compared with other devices. Comprised of only one ring and having a small footprint, makes this modulator an appealing candidate for large scale integration in interconnects systems and RF photonics.