Micro lenses are fabricated using processes which operate on multiple lenses
at a time. In one embodiment, wafer-scale processing includes employing photolithography
for defining gray-scale masks which permit relatively smooth or continuous curvatures
of lens surfaces to be formed by, e.g., reactive ion etching. Processes and materials
are used which achieve desired etching at a sufficiently rapid rate such as etching
to a depth of about 200 micrometers in less than about 10 hours. Wafer-scale molding
processes can also be used. Diffractive features can be formed on or adjacent lens
surfaces to provide functions such as dispersion correction. Also, sub-wavelength
scale features may be etched to provide quarter-wave plate functionality, birefringence,
anti-reflective functions and the like. Structures such as mounting rings and/or
crash stops can be formed integrally with the lens body, eliminating the need to
glue or otherwise couple separate components.
