This Small Business Innovation Research (SBIR) Phase I project seeks to develop a technology to fabricate thin-film spectrally-tunable optical filters with wide bandwidth for operation in the visible and near infrared spectrum. Spectrally-tunable optical filters with electronic controllability are desired in optical imaging systems, such as fluorescence microscopy systems, dual-band cameras, and adaptive optical systems. Such filters can significantly reduce the complexity of the optics in imaging systems and help to enable a lightweight, a small-volume automated imaging system with significantly improved capabilities. The proposed effort will use low-refractive-index nano-rod thin film materials for tunable optical filter fabrication. The nano scale feature size of the nano-rod has negligible scattering effect and enables a nano-rod layer which can be used as a viable optical thin film material. The intellectual merit mainly lies in solving the technical challenges for nano-structured material fabrication, and addressing the optical filter design by combining the optical property and the nano-structure of the low-refractive-index material.
The broader impact/commercial potential of this project is mainly lying on the fact that the availability of wide-band spectrally-tunable optical filters at visible and near infrared spectrum will be extremely beneficial to the next generation of optical imaging technology by enabling the multiple-band imaging function with electronic controllability. Additionally, such filters can be used in any optical system to improve the system's capability with spectral band tunability and controllability, including, but not limited to, multi-band imaging system, spectrally-tunable optical display systems, machine vision system, multi-band detection system, and spectrally-tunable light sources. The proposed electronically tunable optical filter is the core device to enable such advanced applications. Therefore a successful completion of the program could result in a worldwide paradigmatic shift in the optical system development.
This Small Business Innovation Research Phase I project seeks to develop a technology to fabricate thin-film based spectrally-tunable optical filter in the visible and near infrared spectrum. Thin-film optical filters are the most popular optical filter on the market due to their low cost. However, there is no tunable thin-film based optical filter available because conventional optical thin films are not tunable. In this project, a novel optical thin film that has tunable optical thickness has been developed and demonstrated. This tunable optical thin film can be integrated into the optical filter consisting of multi-layer thin film stack to enable a tunable optical filter. Such technology allows the fabrication of large area tunable optical filter based on thin film technology. Additionally, such technology allows the fabrication of variety of tunable optical filters that conventional technology cannot achieve. A simplified tunable band-pass filter has been demonstrated. A characterization method has been developed to demonstrate and measure the spectral tunability of the tunable optical thin film and the optical filter using this tunable optical thin film. The study on controllable tunability has been initiated. The tunable optical thin film allows the fabrication of variety of tunable optical filters that conventional optical filter technology cannot achieve, such as tunable long-pass filter. Such special tunable optical filters are greatly desired in optical imaging instrument, such as fluorescence microscope, for the application of life-science. The fast imaging speed and fully automated imaging function is essential to achieve real-time diagnostics or characterization for life-science application. The technology developed in this project provides the possibility to fabricate the tunable band-pass filters and tunable dichroic filters that can be integrated into the optical imaging instrument to achieve the real-time and automated imaging acquisition.
