In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being leveraged for developing sophisticated photonic sensors. Silicon photonic sensors seek to exploit the strong confinement of light in nano-waveguides to transduce changes in physical state to changes in resonance frequency. In the case of thermometry, thermo-optic coefficient, i.e. changes in refractive index due to temperature, cause the resonant frequency of the photonic device such as a Bragg grating to drift with temperature. We are developing a suite of photonic devices such as on-chip Bragg waveguides, ring resonators and photonic crystal cavities that leverage advances in microwave and C-band light sources to fabricate cost-effective photonic temperature sensors. Our preliminary results indicate that using photonic devices such as a ring resonator we can measure short term temperature fluctuations of >100 μK at room temperature. Photonic sensor technology provides a low cost, lightweight, portable and EMI resistant solution which can be deployed in a wide variety of settings ranging from controlled laboratory conditions, a noisy factory floor, advanced manufacturing, to the variable environment of a residential setting.
Journal of Visualized Experiments
photonics, silicon photonics, waveguide, photonic crystal cavity, C-band, ring resonator