Harnessing birefringence properties in multifunctional GRIN lens based cascades

Graded Index (GRIN) lenses are affordable, flat, rigid lenses commonly used for compact imaging systems. GRIN lenses have the inherent property of radially changing birefringence, a property undesired for most applications.

Researchers at the University of Oxford have drawn previously undesirable birefringence properties of GRIN lenses to build GRIN lens cascades. GRIN lens cascades are light manipulation structures that enable novel extra functionality in commonplace GRIN lens systems, extending their range of applications.

GRIN lenses are sold widely today. Their low mass and size means optical devices using GRIN-lenses can be created in an easier, more stable, compact, low-cost way compared with conventional methods, such as using adaptive spatial light modulators or q-plates.

The GRIN based lens cascade could be applied as a multi-functional optical device which is capable of imaging, phase modulation and polarisation modulation simultaneously.

The main applications include:

• A new vector vortex beam (VVB) generator that could benefit complex light beam engineering as well as modification of the shape of laser beam focus for microscopy and super-resolution applications
• A new orbital angular momentum (OAM) generator that could benefit further microscope techniques including optical tweezing, sensing in astronomy, as well as quantum optics communication
• A new single-shot Mueller matrix measurement probe that could assist minimally invasive surgery techniques to do simultaneous scanning for detecting the boundary of, say a cancerous tumour, as a label-free indicator

Patent protection

A patent has been filed which covers this technology. Oxford University Innovation is interesting in talking to potential partners to aid in the commercialisation of these new methods.