PIC: Mobile in Situ Fourier Transform Spectrometer on a Chip

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Optical spectroscopy excels at chemical identification and is ubiquitous in the sciences as a highly specific and noninvasive probe of molecular structure. Moving forward the integration of miniaturized optical spectrometers into mobile platforms will have unprecedented impact on applications ranging from unmanned aerial vehicles to mobile phones. To address this demand, silicon photonics stands out as a manufacturable platform capable of delivering compact and cost-effective devices and systems. Its implementation in silicon photonics manufacturing will contribute to bringing broadband operation and fine resolution to the chip scale enabling such attributes as compactness, power efficiency, real time operation and low cost. Thus integrated spectrometers will have a profound impact by incorporation into various mobile platforms and creation of distributed sensor networks towards large scale internet of things applications. The proposed research will advance the basic science and technology of engineered CMOS manufactured Si-Photonic integrated systems on a chip. We anticipate that the spectrometer will find applications in monitoring environment, healthcare, national security, and defense applications. The project will provide scientific training for students at graduate and undergraduate levels as well as serve as a platform for outreach, education and collaborative efforts with middle and high schools. Significant efforts have been directed towards the realization of miniaturized, embedded optical spectrometers for spectral analysis in numerous areas of science and technology including remote sensing, planetary sciences, medical research, and pharmaceutical processes. The state of the art Optical Fourier Transform spectroscopy has thus far been relegated as a benchtop instrument owing to the large footprint and mechanical stability necessary for accurate operation. To overcome this limitation, we propose to develop an integrated chip-scale Fourier transform spectrometer that is fully CMOS compatible. This approach will improve the measurement speed, and relax the sampling rate and dynamic range requirements compared to conventional ones, and retain the strong advantages that Fourier transform spectrometers possess compared to other conventional designs, such as superior performance in power throughput, operation in noisy environments, and accuracy. To reach these goals, we propose to achieve the following objectives: (1) design a chip-scale spectrometer on a chip (2) fabricate it as a monolithic integrated device, (3) experimentally test and characterize the performance of the constructed device and (4) devise signal processing algorithms for concatenation of the detected channelized signals to construct high resolution broad band resultant spectra. Rapid prototyping and testing will be performed at UCSD with full scale runs performed at the AIM Photonics foundry. The proposed research is transformative in nature as it will not only mark the first step toward integration of inexpensive, compact, high resolution sensitive spectrometers into mobile phone technology, but also offer a route to ultra-compact networked sensor systems for environmental management, medicine, and security. The project will provide scientific training for students at graduate and undergraduate levels as well as serve as a basis for outreach, education and collaborative efforts with middle and high schools. Engagement of students of diverse ethnicity, gender and economic backgrounds in Science, Technology, Engineering and Mathematics (STEM) will be continued via the ongoing RET, REU, and COSMOS activities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.