Manufacturing optical elements

A method for use in manufacturing a plurality of optical elements, the method comprising:

• providing a substrate having a surface profile, the substrate surface profile defining a plurality of flow stop features for restraining a flow of viscous material over the substrate surface profile;
• providing a mold tool having a mold surface profile;
• dispensing viscous material onto the mold surface profile and/or onto the substrate surface profile;
• disposing the mold surface profile and the substrate surface profile towards one another;
• and
• aligning the mold surface profile and the substrate surface profile relative to one another;
• wherein the mold surface profile and the substrate surface profile are configured so that when the mold surface profile and the substrate surface profile are disposed towards one another and aligned relative to one another, the mold surface profile and the substrate surface profile define therebetween:
• a plurality of optical element cavities, each optical element cavity being configured to define a profile of a corresponding optical element with respect to a corresponding optical axis;
• a plurality of peripheral cavities, each peripheral cavity being disposed around a periphery of a corresponding optical element cavity and each peripheral cavity including one or more corresponding flow stop features of the plurality of flow stop features;
• and
• one or more air flow paths for allowing air to flow out of each peripheral cavity to an environment external to the mold tool and the substrate, and for allowing air to flow into each peripheral cavity from the external environment;
• wherein each optical element cavity and the corresponding peripheral cavity are separated by a corresponding peripheral constriction therebetween, the peripheral constriction defining an upwardly curved surface of the mold surface profile into the peripheral cavity for allowing formation of an epoxy meniscus profile.