Design of a Wavelength-Meter with Measurement Range up to 100nm and 8 pm precision

Hereby, we present a new design for an integrated wavelength meter. The device works by coupling an unknown monochromatic light source to four microring resonators of different free spectral range containing a phase modulator. The output of each ring is coupled to a separate photodiode (PD). The setup relies on modulating the spectral position of ring resonances while monitoring transmitted power with PDs. Thanks to data acquired during calibration, is possible to relate such output powers to a unique wavelength. While state-of the art designs allow for either high precision or broad range, our system does not require any tradeoff between those two characteristic, achieving up to 8 pm precision (for a ring Q factor equal to 2*10^5) and 100 nm of wavelength range. We will discuss how losses influence the measurement speed and the resolution of the device. The structure, although platform independent, will be realized in InP.