Lensless Smart Sensors: Optical and thermal sensing for the Internet of Things

Abstract

Lensless Smart Sensors (LSS) add optical and thermal sensing capabilities to the Internet of Things (IoT) in a form factor that cannot be achieved with traditional lensed systems. Different from lensed systems, LSS is based on diffraction instead of refraction, and different from other diffractive optical elements in that it can operate with a wide field of view (FOV) and over a wide wavelength band. LSS's use of computation to extract information from a captured scene makes LSS a good fit for applications where the goal is not to create an image for human consumption, but for machine viewing (e.g. to trigger actions in a connected device). Since the raw sensed image is encoded by the grating structure, LSS opens applications where the use of a camera would create privacy concerns. This paper describes the operational principle of LSS and discusses three examples in more detail.