Photoelastic effect in silicon ring resonators

The photoelastic effect of Si was measured in a real optical device, a racetrack ring resonator. The sample holder that can induce strain mechanically was fabricated and the strain dependence of resonance wavelength was investigated. The holder can induce a 10(-4) order strain and a 0.1 nm order shift of resonance wavelength induced by this strain was observed. By subtracting the contribution of change in the circumference of the racetrack ring resonator from the resonance wavelength shift, the photoelastic effect was estimated. As a result, the obtained photoelastic coefficient was consistent with that of bulk Si.