Role of Nanoimprint Lithography for Strongly Miniaturized Optical Spectrometers

Optical spectrometers and sensors have gained enormous importance in metrology and information technology, frequently involving the question of size, resolution, sensitivity, spectral range, efficiency, reliability, and cost. Nanomaterials and nanotechnological fabrication technologies have huge potential to enable an optimization between these demands, which in some cases are counteracting each other. This paper focuses on the visible and near infrared spectral range and on five types of optical sensors (optical spectrometers): classical grating-based miniaturized spectrometers, arrayed waveguide grating devices, static Fabry-Perot (FP) filter arrays on sensor arrays, tunable microelectromechanical systems (MEMS) FP filter arrays, and MEMS tunable photonic crystal filters. The comparison between this selection of concepts concentrates on (i) linewidth and resolution, (ii) required space for a selected spectral range, (iii) efficiency in using available light, and (iv) potential of nanoimprint for cost reduction and yield increase. The main part of this review deals with our own results in the field of static FP filter arrays and MEMS tunable FP filter arrays. In addition, technology for efficiency boosting to get more of the available light is demonstrated.

Automated summary

Optical spectrometers and sensors are crucial in metrology and information technology, with factors like size, resolution, sensitivity, spectral range, efficiency, reliability, and cost to consider. Nanomaterials and nanotechnologies have the potential to optimize these demands, which can sometimes conflict with each other. The paper focuses on visible and near infrared ranges, comparing different optical sensors and technologies for efficiency and cost-effectiveness.