Optical wavelength signal detector via tunable micro-ring resonator for sensor applications

This paper reports a compact optical wavelength tracker, which consists of an electrically controlled tunable micro-ring resonator and a flip-chip bonded photodiode. The input optical wavelength is measured and the wavelength change is tracked by analyzing the photocurrent variation of the photodiode. This wavelength tracker has compact size (0.5 mm × 1.5 mm), high resolution (3 pm), cost-effective and can be easily integrated with other devices on a single chip. It offers a simple chip-level optical wavelength tracking and detection approach for low-cost batch production, which has potential applications in optical sensors and fiber communications.