Optical waveguide structure improvements of novel photonic dew point sensor

• Main Author: Yu, Joelle Anya
• Other Authors: Zhang Dao Hua
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/75289
• Institution: Nanyang Technological University

A dew point sensor based on integrated photonics provides a potential humidity measurement solution with higher measurement sensitivity, as well as being significantly smaller and faster than the current industry standard, the chilled mirror hygrometer. This thesis looks to understand and further develop this sensor by examining the photonics structure design. It focuses on two areas and how they affect the sensor’s performance: the shape of the photonics structure and the effects of the operating environment temperature. The investigation into the photonics structure uses Lumerical MODE Solutions simulations and finds that the structure should use a coupling gap of 300nm, should not incorporate a coupling length and should consider using a one-sided design to combine the input and output. The effect of high operating temperatures is considered by analysing previously manufactured sensors’ performances under varying temperatures and benchmarking the current maximum operating temperature as 117°C. It is apparent that the cycling in higher temperatures causes shifts in the alignment with the optical fibres when the sensor is packaged.