Systems, devices, and methods for splitter optics in wearable heads-up displays

A wearable heads-up display (“WHUD”) comprising:

• a support structure that in use is worn on a head of a user;
• a scanning laser projector carried by the support structure;
• a holographic combiner carried by the support structure, wherein the holographic combiner is positioned within a field of view of an eye of the user when the support structure is worn on the head of the user;
• and
• an optical splitter carried by the support structure and positioned in an optical path between the scanning laser projector and the holographic combiner, wherein the optical splitter includes a transparent polygonal structure that comprises:
• an input side oriented to receive laser light from the scanning laser projector and in-couple the laser light into a volume of the optical splitter;
• and
• an output side having N=4 facets, each of the N=4 facets oriented to out-couple a respective portion of the laser light from the volume of the optical splitter and direct the respective portion of the laser light along a respective optical path towards the holographic combiner, wherein:
• the N=4 facets are arranged in a two-by-two array with each one of the N=4 facets sharing a first edge with a first other one of the N=4 facets and a second edge with a second other one of the N=4 facets,
• each one of the N=4 facets comprises a respective rectangular surface oriented at a different angle in three-dimensional space relative to the other ones of the N=4 facets,
• each one of the N=4 facets is oriented to at least partially face away from each of the other ones of the N=4 facets, and
• a respective first vertex of each one of the N=4 facets mates with the respective first vertices of each of the other ones of the N=4 facets to form a vertex on a convex outer surface of the output side of the optical splitter, and wherein:
• the holographic combiner comprises at least one hologram positioned and oriented to receive the respective portions of the laser light from the N=4 facets of the optical splitter and redirect each respective portion of the laser light towards a respective one of N exit pupils at the eye of the user.