Highly curved large-format sensors for infrared imaging

A curved, rather than flat, photoreceptive surface requires fewer optical elements and enhances illumination and sensitivity uniformity for wide-field vision. While such designs are common in vertebrate eyes, creating manmade curved sensing surfaces using high-performance sensors has been technologically challenging. Here, we surpassed previous practices by manipulating the strain within a die using a ductile metal layer. This enabled scalability to large-format sensors, which are valuable for capturing wide viewing angles with high resolution. We showcased this methodology using two types of III-V compound semiconductor photodetectors for mid-wave infrared (MWIR) imaging. The radiometric response of a hybridized fanout chip curved to a solid angle of 0.24 sr - over 300% beyond the limit of standard methods - was evaluated. A fully imaging focal plane array curved to 0.11 sr exhibited >97% operability. This demonstration of a spherically curved, cryogenically cooled MWIR imaging sensor highlights the feasibility of curving sensors comprised of heterogeneous semiconductor layering, which are commonly used in infrared, visible, and ultraviolet imagers.