Oxford University Innovation Ltd

Isis Innovation Limited

Martin James Booth

Patrick Salter

Tony Wilson

Rimvydas Juskaitis

Edward Botcherby

Steve J Elston

Stephen M Morris

Jason Smith

Julian Fells

Joerg Bewersdorf

Mark Andrew Aquilla Neil

Travis J Gould

Chloe C Tartan

Yu-Chen Chen

Yu Chen Chen

Daniel Burke

Chao He

Patrick Stephen Salter

A single-shot Mueller matrix polarimeter (), MMP, comprising: a polarization state generator (), PSG, arranged to receive a source optical field () and provide a probe field () having a plurality of spatial portions, each portion having a different polarization state; a polarization state analyser (), PSA, arranged to receive a modified probe field () resulting from interaction of the probe field generated by the PSG with a sample under investigation, and further arranged to apply, to each of a corresponding plurality of spatial portions of the modified probe field, a plurality of retardances and a plurality of fast axis orientations; and a detector () arranged to detect an output () of the PSA.

Single-shot Mueller matrix polarimeter

The invention provides a method for laser modification of a sample to form a modified region at a target location within the sample. The method comprises positioning a sample in a laser system for modification by a laser; measuring tilt of a surface of the sample through which the laser focusses; using at least the measured tilt to determine a correction to be applied to an active optical element of the laser system; applying the correction to the active optical element to modify wavefront properties of the laser to counteract an effect of coma on laser focus; and laser modifying the sample at the target location using the laser with the corrected wavefront properties to produce the modified region.

Method for laser machining inside materials

Method of laser modifying an optical fibre to form a modified region at a target location within the fibre, comprising positioning at least a portion of an optical fibre in a laser system for modification by a laser, applying a correction to an active optical element of the laser system to modify wavefront properties of the laser to counteract an effect of aberration on laser focus, and laser modifying the optical fibre at the target location using the laser with the corrected wavefront properties to produce the modified region.

Method of laser modification of an optical fibre

A device for modulation of light () having a wavelength, comprising: a first substrate () with a first face () and a second opposite face (), and comprising a first electrode (); a second substrate () adjacent to the second face () and defining a gap between the first and second substrate (), the second substrate () comprising a second electrode (); a responsive liquid crystal layer () disposed in the gap, wherein the responsive liquid crystal layer () has a flexoelectro-optic chiral nematic phase, and is birefringent with an optic axis that tilts in response to an applied electric field between the first and second electrode (); and a mirror adjacent to the second substrate (), the mirror configured to reflect incident circular polarised light while preserving its handedness.

Liquid crystal modulator

A method of fabricating one or more colour centres in a crystal is described. The method comprises focusing a laser into a crystal to induce the creation, modification, or diffusion of defects within a focal region of the laser. Fluorescence detection is used to determine when one or more colour centres are formed within the focal region and the laser is terminated when a desired number of colour centres have been formed. The method enables colour centres to be formed in a crystal with a high degree of control in terms of both the number and location of colour centres within the crystal, and a degree of control over other parameters such as colour centre orientation and local environment. In particular, it is possible to form a well-defined pattern of colour centres within a crystal.

Laser writing for colour centres in crystals

A method is disclosed of electrically controlling state transition of a liquid crystal material in a device (). The device () comprises the liquid crystal material () and a polymeric structure () consisting of polymerised liquid crystal material with a selected liquid crystal state. The method comprises: applying an electric field to the liquid crystal material () to force the liquid crystal material () into a high-energy state; reducing the strength of the electric field to cause a lower-energy state region of the liquid crystal material () to nucleate on at least a part of the polymeric structure ().

Method and apparatus for controlling liquid crystal states

There is provided a method of fabricating a trapped vacancy in a crystal lattice of a target comprising: positioning the target in a laser system, the target containing vacancy trapping elements within the crystal lattice; modifying the crystal lattice within the target by using a laser to generate a lattice vacancy; and annealing the target to cause the lattice vacancy to migrate and be captured by a vacancy trapping element to form the trapped vacancy in the crystal lattice.

Method for trapping vacancies in a crystal lattice

A focusing apparatus for use with an optical system having a high NA objective lens includes an image forming and capturing mechanism for forming an image in an intermediate image zone and for capturing an image by receiving and refocusing light from a selected focal plane within the intermediate image zone, and a focus adjusting mechanism for adjusting the position of the selected focal plane within the intermediate image zone. The image forming and capturing mechanism includes at least one high NA lens. In use, spherical aberration introduced by the high NA objective lens is reduced.

Focusing apparatus and method

Aberrations in stimulated emission depletion microscopy are corrected using an adaptive optics approach using a metric which combines both image sharpness and brightness. Light modulators () are used to perform aberration correction in one or more of the depletion path (), the excitation path (), or the emission path from sample to detector.

Stimulated emission depletion microscopy

A focusing apparatus for use with an optical system having a high NA objective lens includes an image forming and capturing apparatus for forming an image in an intermediate image zone, and for capturing an image by receiving and refocusing light from a selected focal plane within the intermediate image zone, and a focus adjusting apparatus for adjusting the position of the selected focal plane within the intermediate image zone. The image forming and capturing apparatus includes at least one high NA lens. In use, spherical aberration introduced by the high NA objective lens is reduced.

The wavefront sensing device consists of a light source, a binary phase mask ( ), a fixed focus lens ( ) and at least two finite sized spatially separated detectors ( ) positioned in the plane of focus of the wavefront sensing device. The binary phase mask ( ) simultaneously applies a positive bias and a negative bias to the wavefront of the incident light such that a pair of spatially separated light points are generated in the plane of focus and detected by the detectors ( ). The difference in intensity between the pair of light points is representative of the aberration of the wavefront of the incident light from the ideal.

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Oxford, United Kingdom

Martin James Booth