Qinetiq Limited

Other

The Secretary of State for Defence in Her Majesty's Government of the

Andrew Maxwell Scott

Mark Edward McNie

Andrew Charles Lewin

Kevin Michael Brunson

Keith Loder Lewis

Kevin Dennis Ridley

Christopher William Slinger

Gilbert William Smith

Simon Christopher Woods

Andrew J Turner

David J Jackson

Steven Matthew Stone

Henry M Prain

A method and corresponding apparatus for coupling an optical beam into a first end of an optical fiber includes two steps. First, light is coupled into a second end of the optical fiber such that an optical reference beam is output from the first end of the optical fiber. Second, at least one beam parameter of the optical beam is matched with the corresponding beam parameter of the optical reference beam. The second step may be performed using a wavefront sensor.

Apparatus and method for coupling an optical beam with an optical fibre

A retro-reflective identification tag capable of modulating an optical signal whereby to support bi-directional communication with an associated remote optical interrogation device. The tag comprises a MOEMS modulating layer over a retro-reflective substrate, giving the tag a wide angle of effective operation. The tag modulator may optionally be switched on only responsive to detection of a precursor beam from the interrogation system in order to save power. The interrogation device may make use of multiple optical wavelengths for communicating with the tag.

Dynamic optical reflector and interrogation system

Methods of providing duplex free-space optical, communication comprising receiving a time-shift keying (TSK) encoded signal and selectively re-modulating&#x2014;and optionally retro-reflecting &#x2014;received TSK pulses so as to transmit an on-off keying (OOK) signal wherein modulation is achieved by operating a micro-opto-electronic mechanical system (MOEMS) device having a oscillation period, the difference in timing between logic 1 and logic 0 pulses of the TSK encoded signal being such that each pulse arrives at a time within a single MOEMS device oscillation period chosen to ensure high or low transmissivity through the MOEMS device independent of incident TSK encoded signal pulse value (0 or 1).

Method of providing duplex optical communications and optical modulator therefor

A micro-opto-electro-mechanical systems (MOEMS) electro optical modulator () having an electrically tuneable optical resonator comprising an asymmetric Fabry-Perot etalon incorporating a mirror () resiliency biased with respect to a substrate () and moveable in relation thereto in response to a voltage applied there-between. The optical modulator () is capable of modulating electromagnetic radiation having a plurality of wavelengths. The modulator is adapted to modulate the transmission of short wave infrared radiation (SWIR), medium wave infrared radiation (MWIR) and long wave infrared radiation (LWIR) and the reflection of visible radiation. A spatial optical modulator having a plurality of said MOEMS optical modulators (). A method of addressing said spatial optical modulator.

Optical modulator

An optical modulator comprising a spacing-controllable etalon having at least one sprung micro-mirror suspended above a substrate. At least one electrically insulating stop is provided between the micro-mirror and the substrate to avoid short-circuit when the micro-mirror is drawn towards the substrate by an applied voltage. An optical detector detects the time of arrival of a first laser pulse. A control circuit predicts from this an arrival time of the next incident laser pulse and, responsive to a control signal, either retains the micro-mirror in its pulled-down state held against the insulating stops or releases the micro-mirror at a time predicted to maximise or minimise the light transmitted through the modulator. After a time interval calculated to permit a predetermined number of mechanical oscillations, the micro-mirror is pulled back down onto the stops.

Optical modulation

Apparatus for indicating the departure of a shape of an object from a specified shape is described. The apparatus includes a light source for directing an incident beam of radiation onto the object, and an inspecting device for inspecting the final beam after transmission by or reflection from the object. The apparatus is arranged so that the final beam will have a substantially planar wavefront when the object has the specified shape, and said inspecting device is arranged to determine any departure of the wavefront of the final beam from planarity. In one embodiment, the inspecting device includes a beamsplitter, for example a diffraction grating or hologram, and a detector such as a CCD camera. The beamsplitter is then arranged to split the final beam into two or more beams and to direct the two or more beams to laterally displaced locations on the detector.

Surface shape measurement apparatus and method

Optical apparatus for simultaneously focussing first and second coaxially spaced object planes in respective separate first and second areas of a common image plane(such as the sensor of a CCD camera) comprises non-diffractive beamsplitter means for receiving light from said object planes along a common pathfor transmission to said first and second image areas along respective first and second optical paths, and reflective or transmissive focussing meansarranged to bring said first and second object planes into focus in said first and second areas. The object planes may be differentiated by having different length paths(different physical lengths and/or using a differential optical delay), and/or by having different focussing powers in the two paths. In an add-on for a camera, differently curved mirrors of long focal length modify the main camera lens. Polarising optics may be used to separate the two images. The apparatus may be used for 3-D imaging or wavefront analysis.

Imaging system

A multi-pass optical amplifier system is provided comprising an amplifier medium ( ) and at least one relay imaging telescope ( ) for imaging light from the amplifier medium onto a primary light directing optical component, such as a mirror ( ) and for imaging light directed back from a primary light directing optical component ( ) into the amplifier medium so that light is re-passed through the amplifier medium. The system further includes a phase conjugate mirror arrangement for intercepting light between passes for the amplifier medium to generate a phase conjugate reflection of the light incident on it. Preferably, the system is arranged such that a light beam is incident on phase conjugate mirror ( ), after having passed through the amplifier medium a predetermined number of times and the phase conjugate reflection retraces the path of the incident beam. The system may be arranged such that a light beam from the amplifier medium which is re-imaged into the amplifier medium is spatially separated from itself at at least one point in its path between passes of the amplifier medium in order that it can be intercepted by additional light directing optical components, such as a prism ( ).

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Worcestershire, United Kingdom

Andrew Maxwell Scott