Main . Photonic structures that can perform mathematical operations and solve equations are becoming increasingly popular due to the resurgence of optical analogue computing with the promise of low-power, high-speed, parallel computations enabled by light1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11. Specifically, designing a photonic structure for performing robust linear operations has central importance in a range of applications, including optical imaging12...