A new publication from Opto-Electronic Advances; DOI 10.29026/oea.2022.210100 considers ultrahigh-resolution on-chip spectrometer with silicon photonic resonators.
Spectrometer is one of the most popular instruments for spectral analysis, and has been used in the fields of biosensor, food safety, drug detection, clinical diagnosis, and environmental monitoring. Traditional spectrometers usually are large and expensive, limiting the application scenario greatly. The volume miniaturization and the system integration has been well recognized for spectrometers as a trend. On-chip spectrometers have unique advantages in size, weight, power consumption and cost. It is still very challenging to realize on-chip spectrometers with ultra-high resolution for the applications in many fields such as smart phones, atmospheric monitoring, and Aerospace Exploration.
The authors of this article propose a silicon-based high-performance on-chip spectrometer with an ultra-compact size and an ultra-high resolution. In particular, the configuration consists of an ultra-narrow-band filter and wideband filters array was introduced.
The ultra-high-Q resonator was realized with Euler-bends, enabling ultra-high-resolution wavelength-selective filtering. Meanwhile, the wideband filter array was used to achieve an extended working window for the on-chip spectrometer. The demonstrated on-chip spectrometer has a footprint as compact as 0.35 mm2 and a resolution as high as 0.005 nm (which is the highest for on-chip dispersive spectrometers). The working window is about 10 nm and the ratio between the working window and the resolution is up to ~2000, which is the record for spectrometers with a footprint less than 1 mm2. The proposed spectrometer breaks the bottleneck of insufficient resolution of the dispersive chip-level spectrometer. It is expected that the present ultrahigh-resolution on-chip spectrometer plays an important role in environmental monitoring, aerospace and many other fields, especially in the field of spectral analyzing in smart phones.
Article reference: Zhang L, Zhang M, Chen TN, Liu DJ, Hong SH et al. Ultrahigh-resolution on-chip spectrometer with silicon photonic resonators. Opto-Electron Adv 5, 210100 (2022). doi: 10.29026/oea.2022.210100
Keywords: integrated photonics / silicon / spectrometer / resonator
