Abstract: An optical biometric imaging device comprising: an image sensor comprising a plurality of photodetector pixels; a plurality of collimating structures arranged above the image sensor, the collimating structures being configured to limit the incident angle of light reaching the image sensor to be lower than a first predetermined incident angle ?1; wherein at least a subset of the collimating structures comprises a light-blocking element configured to block light having an incident angle lower than a second predetermined incident angle ?2, the second incident angle being lower than the first incident angle, wherein the light-blocking element is configured to allow light having an incident angle between the first and second predetermined incident angles to pass and wherein the light-blocking element is configured to block light within a first predetermined wavelength range.