Freeform varifocal optical assembly

A display comprising:

• a light source configured to emit image light;
• and
• a freeform varifocal optical assembly configured to guide the image light to an eyebox of the display, the freeform varifocal optical assembly comprising:
• at least three optical modules, each optical module comprising a corresponding plurality of polarization sensitive optical elements, wherein each optical module is associated with a corresponding Zernike polynomial, wherein, for each optical module, the corresponding plurality of optical elements comprises a corresponding property associated with the corresponding Zernike polynomial, and wherein the corresponding Zernike polynomial associated with each optical module is different,
• wherein one or more optical stages in each optical module comprises a switchable optical retarder and an optical element comprising a Pancharatnam-Berry phase (PBP) lens or a polarization sensitive hologram (PSH) lens, wherein the switchable optical retarder is configured to transmissively convert light of a first polarization or a second polarization into light of the second polarization or the first polarization, respectively,
• wherein the optical element of a first optical module of the optical modules is configured to receive light transmitted through the switchable optical retarder of the first optical module and is configured to change a higher order aberration compensation depending on whether the light transmitted through the switchable optical retarder has the first polarization or the second polarization.

A method comprising:

• transmitting light through at least three optical modules, each optical module comprising a plurality of polarization sensitive optical elements, wherein each optical module is associated with a corresponding Zernike polynomial, wherein for each optical module, the corresponding plurality of optical elements comprises a corresponding property associated with the corresponding Zernike polynomial, wherein the corresponding Zernike polynomial associated with each optical module is different,
• wherein one or more optical stages in each optical module comprises a switchable optical retarder and an optical element comprising a Pancharatnam-Berry phase (PBP) lens or a polarization sensitive hologram (PSH) lens, wherein the switchable optical retarder is configured to transmissively convert light of a first polarization or a second polarization into light of the second polarization or the first polarization, respectively,
• wherein the optical element of a first optical module of the optical modules is configured to receive light transmitted through the switchable optical retarder of the first optical module and is configured to change a higher order aberration compensation depending on whether the light transmitted through the switchable optical retarder has the first polarization or the second polarization;
• and
• adjusting the focal power of one or more of the at least three optical modules by changing respective states of one or more optical elements of the plurality of optical elements in the one or more of the at least three optical modules.