Image sensors have benefited immensely from the steady advances in semiconductor fabrication, resulting in an order of magnitude resolution increase every decade for the last three decades. Moore?s law has had a similar impact on both computing and image sensor technology. In addition to the sensor, however, cameras and other imaging devices require lenses whose manufacturing processes has not benefited from Moore?s law. As a result the ultimate scaling and cost of imaging devices is limited by physical optics. This research project involves the development of Lens-Free Cameras (LFCs), a novel imaging architecture for visible, short-wave infrared (SWIR), mid-wave infrared (MWIR) and thermal wavelengths that exploits amplitude multiplexing masks and computational demultiplexing algorithms to replace lenses in traditional cameras. Such lensless imaging technology will produce thin cameras that can be directly fabricated using contemporary semiconductor fabrication processes, thereby benefitting from the scaling laws of semiconductor fabrication.
An LFC consists of an image sensor and a thin amplitude modulation mask fabricated at a few hundreds of microns above the image sensor surface. The amplitude modulation mask creates a linear mapping between the scene and the sensor measurements. The linear system describing the LFC contains millions of variables and millions of measurements. Solving this large linear system of equations will allow for the reconstruction of high resolution images from the sensor measurements. This project will focus on the fabrication of a thin lensfree camera. The result of this fabrication process will be the world?s first camera less than a millimeter thick. The advance in lensfree cameras will be more widely applicable to several challenging applications such as microscopy, endoscopy and other space constrained imaging scenarios.
