Nonconservative Coupling in a Passive Silicon Microring Resonator

The authors report on nonconservative coupling in a passive silicon microring between its clockwise and counterclockwise resonance modes. The coupling coefficient is adjustable using a thermo-optic phase shifter. The resulting resonance of the supermodes due to nonconservative coupling is predicted in theory and demonstrated in experiments. This Letter paves the way for fundamental studies of on-chip lasers and quantum photonics, and their potential applications.

Figure 1

(a) Schematic of the nonconservative coupling mechanism investigated in this Letter. (b) Optical image of the device tested.

Figure 2

Spectrum of the device in the initial situation without thermal tuning.

Figure 3

Resonance tuning results with respect to different thermal phase shifter powers [(a) 0, (b) 1.4, (c) 5.6, (d) 12.6, (e) 14.3, and (f) 15.3 mW]. All of the spectra are plotted on a linear scale.