Search for: All records

Abstract The proliferation of Internet-of-Things has promoted a wide variety of emerging applications that require compact, lightweight, and low-cost optical spectrometers. While substantial progresses have been made in the miniaturization of spectrometers, most of them are with a major focus on the technical side but tend to feature a lower technology readiness level for manufacturability. More importantly, in spite of the advancement in miniaturized spectrometers, their performance and the metrics of real-life applications have seldomly been connected but are highly important. This review paper shows the market trend for chip-scale spectrometers and analyzes the key metrics that are required to adopt miniaturized spectrometers in real-life applications. Recent progress addressing the challenges of miniaturization of spectrometers is summarized, paying a special attention to the CMOS-compatible fabrication platform that shows a clear pathway to massive production. Insights for ways forward are also presented. 

The demand for ultra-long waveguides with tunable refractive index keeps growing in various applications, such as tunable delay line, Fourier transform spectrometers, microwave filters, signal processors, programmable photonics circuits, Lidar etc. Thermal tuning using integrated heaters is so far the most popular option to modulate the waveguide index due to simplicity of fabrication, high tuning efficiency, wide tuning range as well as absence of spurious amplitude modulation. But for ultra-long waveguide, the heater design needs to take the in-plane geometry into consideration in order to optimize particular performance metrics. Therefore, in this manuscript we report both theoretical modelling and experimental characterization of integrated heaters for ultra-long waveguides that pays special attention to the impacts of heater geometry.