Fig. 1: The concept of I-AO.
a An optical system affected by spatial intensity error sources, with a distorted focal spot. In this work, spatially varying intensity losses are introduced through three sources: (1) a spatial light modulator (SLM) sandwiched by two crossed polarisers for precise control of intensity distribution, generating arbitrary intensity errors; (2) a thin biomedical sample (fibrotic tissue); and (3) a material sample (birefringent crystals). b Integration of an I-AO corrector restores intensity uniformity, addressing spatially varying loss to achieve an ideal focus. The I-AO corrector employs an SLM sandwiched by two crossed polarisers for pixelated intensity correction at the pupil plane, with an additional deformable mirror (DM) to compensate for phase errors. c Conceptual schematic of sensor-based I-AO with dual-loop feedback correction (SB1 and SB2), where an intensity sensor measures the intensity errors directly from the pupil plane. d Conceptual schematic of sensorless I-AO with dual-loop feedback correction (SL1 and SL2), where the intensity error is estimated using images obtained from the focal plane. The experimental setup is shown in Supplementary Note 1, and details of the dual-loop mechanism can be found in Supplementary Note 2
