Abstract:
There is provided a wearable display comprising a light source emitting light of a first wavelength; a first SBG device having a front side and a rear side; first and second transparent plates sandwiching said SBG device; independently switchable transparent electrode elements applied to the opposing surfaces of said transparent plates, a means for spatio-temporally modulating light from the light source to provide image light and a means for coupling the image light into the light guide formed by the two transparent plates and the SBG device. The SBG device comprises a multiplicity of selectively switchable grating regions. The SBG device diffracts image into the pupil of an eye.
Abstract:
A device for reducing laser speckle using a micro scanner and a holographic diffuser. The micro scanner includes a first transparent optical substrate with an input surface and an output surface and a second transparent optical substrate with an input surface and an output surface and a variable refractive index medium sandwiched between the output surface of the first substrate and the input surface of the second substrate. Transparent electrodes are applied to the output surface of the first substrate and the input surface of the second substrate. The electrodes are coupled to a voltage generator. The input surface of the first substrate is optically coupled to a laser source. The input surface of the second substrate is configured as an array of prismatic elements. At least one of the input surface of the first substrate or the output surfaces of the second substrate is planar.
Abstract:
A color sequential illumination device including in series: first and second light sources; a condenser lens; and a grating device. The grating device includes at least one Bragg grating. The condenser lens directs light from the first and second sources into the grating device at first and second incidence angles respectively. The grating device diffracts light from the first and second sources into a common direction. Desirably, the Bragg gratings are Electrically Switchable Bragg Gratings. In one embodiment the light sources are Light Emitting Diodes. Alternatively lasers may be used.
Abstract:
There is provided a device for reducing laser speckle comprising: a first transparent substrate; a second transparent substrate; an SBG sandwiched between said substrates; and transparent electrodes applied to said substrates. The first substrate is optically coupled to a laser source. The face of the second substrate in contact with the SBG is configured as an array of prismatic elements.
Abstract:
There is provided a wearable display comprising at least one Switchable Bragg Grating (SBG) device recorded in at least one Holographic Polymer Dispersed Liquid Crystal (HPDLC) layer. Each HPDLC layer is sandwiched between first and second transparent plates to which transparent electrodes have been applied. Each SBG device is characterised in that it provides a grating in a separate switchable region and is clear elsewhere. Each SBG device has a diffracting state and a non diffracting state. The transparent plates and HPDLC layers form a laminar structure which functions as a light guide. In one embodiment of the invention the display magnifies and forms a virtual image of information provided by an external image generator. In one embodiment of the invention the display and forms a virtual image of an image of information encoded in the SBG device.
Abstract:
An Electrically Switchable Bragg Grating (ESBG) despeckler device comprising at least one ESBG element recorded in a hPDLC sandwiched between transparent substrates to which transparent conductive coatings have been applied. At least one of said coatings is patterned to provide a two-dimensional array of independently switchable ESBG pixels. Each ESBG pixel has a first unique speckle state under said first applied voltage and a second unique speckle state under said second applied voltage.
Abstract:
Light from an image displayed on a display screen 10 is transmitted to an observer's eye 11 by way of a dynamic optical element 12 (such as a spatial light modulator or an electrically switchable holographic composite) which acts as a lens. The characteristics of the dynamic optical element 12 can be altered so that it acts sequentially to direct light of different colors to the observer's eye. In one optional embodiment emitters 17 on the display screen 10 emit infra-red radiation which is projected by the dynamic lens 12 as a broad wash onto the eye 11. Infra-red radiation reflected back from the eye 11 is focussed by the dynamic lens 12 onto detectors 18 also provided on the display screen 10. The detectors 18 are thus able to sense the direction of eye gaze, and the dynamic lens 12 is controlled in dependence on this to create an area of high resolution in an area of interest centered on the direction of gaze, which is moved to follow the eye gaze as its direction alters. Other than in the area of interest, the dynamic lens 12 has a relatively low resolution.
Abstract:
A general purpose sensor architecture integrating a surface enhanced Raman spectroscopy (SERS) substrate, a diffractive laser beam delivery substrate and a diffractive infrared detection substrate is provided that can be used to implement a low-cost, compact lab-on-a-chip biosensor that can meet the needs of large-scale infectious disease testing. The sensor architecture can also be used in any other application in which molecules present in the liquid, gaseous or solid phases need to be characterized reliably, cost-effectively and with minimal intervention by highly skilled personnel.
Abstract:
A general purpose sensor architecture integrating a surface enhanced Raman spectroscopy (SERS) substrate, a diffractive laser beam delivery substrate and a diffractive infrared detection substrate is provided that can be used to implement a low-cost, compact lab-on-a-chip biosensor that can meet the needs of large-scale infectious disease testing. The sensor architecture can also be used in any other application in which molecules present in the liquid, gaseous or solid phases need to be characterized reliably, cost-effectively and with minimal intervention by highly skilled personnel.
Abstract:
A general purpose sensor architecture integrating a surface enhanced Raman spectroscopy (SERS) substrate, a diffractive laser beam delivery substrate and a diffractive infrared detection substrate is provided that can be used to implement a low-cost, compact lab-on-a-chip biosensor that can meet the needs of large-scale infectious disease testing. The sensor architecture can also be used in any other application in which molecules present in the liquid, gaseous or solid phases need to be characterized reliably, cost-effectively and with minimal intervention by highly skilled personnel.