Abstract: Described herein is a diffraction grating (1) for use in an optical system. The diffraction grating includes a substrate (2) and an array of elongate diffracting elements (3) arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Abstract: Described herein is a calibration system (25) for a wavelength selective switch (1). The switch (1) is adapted for dynamically switching optical beams (5, 7) along respective trajectories between input and output ports disposed in an array (3) using a reconfigurable Liquid crystal on silicon (LCOS) spatial light modulator device (17). The calibration system (25) includes a monitor (27) for projecting an optical monitor beam (29) through at least a portion of the switch (1) onto the LCOS (17) and detecting the monitor beam (29) reflected from the LCOS (17). In response, system (25) provides a calibration signal (33) to an active correction unit (35) for applying a correction to one or more of the trajectories while maintaining a constant switching state in the LCOS (17).

Abstract: A distributed optical detection system comprising: a broadband optical source; and a phase and amplitude receiver for measuring phases and amplitudes of distributed backscattered signals from a sensing medium. Methods of quantitatively sensing optical path length changes along a sensing medium in a distributed manner are also disclosed.

Abstract: Described herein is a calibration system (25) for a wavelength selective switch (1). The switch (1) is adapted for dynamically switching optical beams (5, 7) along respective trajectories between input and output ports disposed in an array (3) using a reconfigurable Liquid crystal on silicon (LCOS) spatial light modulator device (17). The calibration system (25) includes a monitor (27) for projecting an optical monitor beam (29) through at least a portion of the switch (1) onto the LCOS (17) and detecting the monitor beam (29) reflected from the LCOS (17). In response, system (25) provides a calibration signal (33) to an active correction unit (35) for applying a correction to one or more of the trajectories while maintaining a constant switching state in the LCOS (17).

Abstract: Methods and apparatus are presented for obtaining high-resolution 3-D images of a sample over a range of wavelengths, optionally with polarisation-sensitive detection. In preferred embodiments a spectral domain OCT apparatus is used to sample the complex field of light reflected or scattered from a sample, providing full range imaging. In certain embodiments structured illumination is utilised to provide enhanced lateral resolution. In certain embodiments the resolution or depth of field of images is enhanced by digital refocusing or digital correction of aberrations in the sample. Individual sample volumes are imaged using single shot techniques, and larger volumes can be imaged by stitching together images of adjacent volumes.

Abstract: Apparatus and methods are presented for enhancing the acquisition speed or performance of Fourier domain optical coherence tomography. In preferred embodiments a plurality of wavelength combs containing interleaved selections of wavelengths from a multi-wavelength optical source are generated and projected onto a sample. In certain embodiments the wavelength combs are projected simultaneously onto a plurality of regions of the sample, while in other embodiments the wavelength combs are projected sequentially onto the sample. Light in the wavelength combs reflected or scattered from the sample is detected in a single frame of a sensor array, and the detected light processed to obtain a tomographic profile of the sample. In preferred embodiments the wavelength comb generator comprises a wavelength interleaver in the form of a retro-reflective prism array for imparting different displacements to different selections of wavelengths from the optical source.

Abstract: Methods and apparatus are presented for obtaining high-resolution 3-D images of a sample over a range of wavelengths, optionally with polarisation-sensitive detection. In preferred embodiments a spectral domain OCT apparatus is used to sample the complex field of light reflected or scattered from a sample, providing full range imaging. In certain embodiments structured illumination is utilised to provide enhanced lateral resolution. In certain embodiments the resolution or depth of field of images is enhanced by digital refocusing or digital correction of aberrations in the sample. Individual sample volumes are imaged using single shot techniques, and larger volumes can be imaged by stitching together images of adjacent volumes.

Abstract: Methods and apparatus are presented for multichannel optical coherence tomography. Light from a wavelength tuneable or steppable optical source is separated into one or more sample beams and one or more reference beams, and the one or more sample beams directed onto a sample to form one or more interaction regions. A plurality of returning probe beams are collected and mixed with the one or more reference beams to form an interference pattern comprising a plurality of interferograms having at least two distinct carrier frequencies. The multichannel optical apparatus can be provided with polarisation discrimination by mixing the returning probe beams with two orthogonally polarised reference beams to form one or more interference patterns each comprising a plurality of interferograms having at least two distinct carrier frequencies.

Abstract: Methods and apparatus are provided for optical coherence metrology or tomography across an extended area of an eye with improved registration. At least two optical coherence tomograms are acquired, with each tomogram containing data from regions of an anterior surface of the eye that are at least partially overlapping, and data from one or more deeper structures such as the retina or the anterior or posterior lens surfaces. The tomograms are then processed to register the data from the overlapping portions of the anterior surface regions, thereby registering the data from the deeper structures. In certain embodiments the reference arm of the apparatus comprises a compound reflector having at least two axially separated reflective surfaces for applying differential delays to different portions of the reference beam. The depth of field of the apparatus is thereby extended to enable measurement of eye length.

Abstract: Method and systems are presented for analysing a wavefront using a spectral wavefront analyser to extract optical phase and spectral information at a two dimensional array of sampling points across the wavefront, wherein the relative phase information between the sampling points is maintained. Methods and systems are also presented for measuring an eye by reflecting a wavefront of an eye and measuring the wavefront at a plurality of angles to provide a map of the off-axis relative wavefront curvature and aberration of the eye. The phase accuracy between wavelengths and sample points over a beam aperture offered by these methods and systems have a number of ocular applications including corneal and anterior eye tomography, high resolution retinal imaging, and wavefront analysis as a function of probe beam incident angle for determining myopia progression and for designing and testing lenses for correcting myopia.

Abstract: Described herein is a wavelength selective switch (WSS) type optical switching device (1) configured for switching input optical beams from input optical fiber ports (3, 5 and 7) to an output optical fiber port (9). Device (1) includes a wavelength dispersive grism element (13) for spatially dispersing the individual wavelength channels from an input optical beam in the direction of a second axis (y-axis). The optical beams propagate from input ports (3, 5 and 7) in a forward direction and are reflected from a liquid crystal on silicon (LCOS) device (11) in a return direction to output port (9). The input optical beams are transmitted through a port selecting module (21), which provides polarization diversity to device (1) and provides capability to restrict optical beams returning from LCOS device (11) from being coupled back into input ports (3, 5 and 7).

Abstract: Described herein are embodiments of a diffractive optical element (23) such as a grism. In one embodiment, the diffractive optical element (23) includes an input surface (31) configured to receive an input optical signal (29), a diffractive surface (33) adapted to spatially disperse the input optical beam (29) into a dispersed signal and an output surface (35) configured to output the dispersed signal from the diffractive optical element. The input surface (31) and the diffractive surface (33) are non-parallel and the diffractive surface (33) is formed in situ by a photolithographic technique.

Abstract: Described herein is a diffraction grating (1) for use in an optical system. The diffraction grating includes a substrate (2) and an array of elongate diffracting elements (3) arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Abstract: Methods and apparatus are presented for confocal microscopy using dispersed structured illumination. In certain embodiments the apparatus also comprises an optical coherence tomography (OCT) system, and OCT images acquired from two or more regions of a sample are registered using a corresponding set of two or more larger area images acquired with the confocal microscopy system. In preferred embodiments the apparatus is suitable for analysing the retina of an eye. The confocal microscopy system can be operated in a purely intensity mode or in a coherent mode. In other embodiments a confocal microscopy system using dispersed structured illumination is utilised for surface metrology.

Abstract: Described herein is a diffraction grating (1) for use in an optical system. The diffraction grating includes a substrate (2) and an array of elongate diffracting elements (3) arranged in a grating profile across the substrate. The grating profile imparts a predefined phase change to optical beams to at least partially correct the beams for optical aberrations present in the optical system.

Abstract: Described herein is a spatial light modulator (15) for modulating the phase, retardation or polarization state of an incident optical signal propagating in a first dimension. The optical phase modulator (15) includes a liquid crystal material (17) and a pair of electrodes (19 and 21) for supplying an electric potential across the liquid crystal material (17) to drive liquid crystals in a predetermined configuration. Modulator (15) also includes a diffractive optical element (29) disposed adjacent a first electrode (19). Element (29) includes a first array of diffractive elements (31) formed of a first material having a first refractive index and extending in a second dimension substantially perpendicular to the first dimension. Elements (31) are at least partially surrounded by a second material (33) formed of a lower refractive index.

Abstract: A holographic display image projector system including an input light source for generating an at least partially coherent optical input beam and an imaging system for transforming an image representation in the Fourier domain into a corresponding holographic image in the spatial domain. The image projector includes a spatial light modulator having a reflective phase manipulating surface and being responsive to an electric control signal to generate a two-dimensional phase profile on the reflective phase manipulation surface to diffract the optical input beam into a diffracted beam having a plurality of diffraction components angularly separated in a first dimension. A coupling prism having a first surface positioned such that a first subset of the diffraction components is refracted through the first surface to the imaging system, wherein upon refraction, an angular separation of the first subset of diffraction components is increased by at least a factor of 2.

Abstract: A holographic display image projector system including an input light source for generating an at least partially coherent optical input beam and an imaging system for transforming an image representation in the Fourier domain into a corresponding holographic image in the spatial domain. The image projector includes a spatial light modulator having a reflective phase manipulating surface and being responsive to an electric control signal to generate a two-dimensional phase profile on the reflective phase manipulation surface to diffract the optical input beam into a diffracted beam having a plurality of diffraction components angularly separated in a first dimension. A coupling prism having a first surface positioned such that a first subset of the diffraction components is refracted through the first surface to the imaging system, wherein upon refraction, an angular separation of the first subset of diffraction components is increased by at least a factor of 2.

Abstract: Methods and apparatus are presented for obtaining high-resolution 3-D images of a sample over a range of wavelengths, optionally with polarisation-sensitive detection. In preferred embodiments a spectral domain OCT apparatus is used to sample the complex field of light reflected or scattered from a sample, providing full range imaging. In certain embodiments structured illumination is utilised to provide enhanced lateral resolution. In certain embodiments the resolution or depth of field of images is enhanced by digital refocusing or digital correction of aberrations in the sample. Individual sample volumes are imaged using single shot techniques, and larger volumes can be imaged by stitching together images of adjacent volumes.

Abstract: In an example embodiment, a WDM array includes an optical filter, N common ports, N reflection ports, and N pass ports. The N common ports may be positioned to a first side of the optical filter. N may be greater than or equal to two. The N reflection ports may be positioned to the first side of the optical filter. The N pass ports may be positioned to a second side of the optical filter opposite the first side.