Abstract:
An optical measurement apparatus comprises an optical system. The optical system comprises a source and an image capture device. The source is arranged to generate, when in use, a beam of electromagnetic radiation. Further, the optical system is arranged to direct the beam of electromagnetic radiation to a location to be measured. The optical measurement apparatus also comprises a feedback arrangement arranged to receive a reflected beam from the location to be measured and to provide feedback information in response to receipt of the reflected beam, the feedback information being indicative of degree of alignment of the location to be measured with the optical system.
Abstract:
A multimode optical fibre communications system, and in particular to a system in which non-linearities in the propagation of the signal through a multimode optical communications channel degrade the signal presented to the receiver. The system includes an optical transmitter unit for connection to a multimode optical fibre transmission link. The transmitter unit has a data input for receiving an input data signal, a data signal processing circuit and a source of optical radiation. The data signal processing circuit is arranged to receive the input data signal from the data input and to provide a processed data signal to the source of optical radiation and the source of optical radiation is arranged to generate from this an optical signal for transmission by a multimode optical fibre. The data processing circuit is arranged to provide from the input data signal a non-inverted data signal and an inverted data signal, receive a control signal for controlling the generation of the processed data signal, apply a controllable delay in accordance with the control signal to at least one of the non-inverted and inverted data signals, and combine the non-inverted and inverted signals after the application of the controllable delay(s) and gain factor(s) to generate the processed data signal.
Abstract:
An arrangement for optical fibre communications, for used, e.g., in millimetre (MM) fibre transmission systems includes: a source (1) of optical radiation defining an offset launch path of optical radiation (R) into an optical fibre (F), and at least one active element (3,4; 6; 7) actuatable to selectively vary said offset launch path in order to achieve an adjustable offset launch of said optical radiations (R) into said optical fibre (F).
Abstract:
An optical component in the form of a right angled triangular prism having a first side, a second side orthogonal to the first side, and a third side generally inclined to the first and second sides to reflect optical radiation incoming from the first side towards the second side. The first and second sides have semi-reflecting surfaces acting as etalon surfaces providing an interferometric pattern. The optical transmittance between the first and the second sides is wavelength dependent and the radiation exiting the second side of the component is rotated 90 degrees to the radiation entering the first side.
Abstract:
An optoelectronic device, for example a laser diode transmitter or receiver module is disclosed having thermoelectric control of the operating temperature of the device.
Abstract:
An optical measurement apparatus comprises an optical system (100). The optical system (100) comprises a source (102) and an image capture device (112). The source (102) is arranged to generate, when in use, a beam of electromagnetic radiation. Further, the optical system (100) is arranged to direct the beam of electromagnetic radiation to a location to be measured (132). The optical measurement apparatus also comprises a feedback arrangement (400, 602, 604) arranged to receive a reflected beam from the location to be measured and to provide feedback information in response to receipt of the reflected beam, the feedback information being indicative of degree of alignment of the location to be measured with the optical system.
Abstract:
An optoelectronic device, for example a laser diode transmitter or receiver module is disclosed having thermoelectric control of the operating temperature of the device.
Abstract:
A control loop detects the presence of cross-talk between first, second and third adjacent amplitude modulated wavelength division modulated channels of an optical communications system. A receiver including a demultiplexer, such as an Arrayed Waveguide Grating (AWG), receives portions of the energy in the channels to derive first, second and third electrical signals that are respectively replicas of the modulation of the first, second and third channels. Wavelength drift of the carried frequencies of the channels in detected by comparing the three signals in an electronic combinatorial logic unit.
Abstract:
An optical assembly for use in an optical telecommunications system and method for aligning the optical assembly. The assembly uses a pair of ball bearings to support an optical fibre on a baseplate. The optical fibre is aligned with respect to an optical device and then the first ball bearing is inserted and welded in place. The fibre alignment is then fine tuned and the second ball bearing is inserted and welded in place, thereby providing a simpler and more accurate method of aligning an optical fibre to an optical device.
Abstract:
An apparatus for determining the wavelength of light emitted by, for example, a laser, includes three photodiodes. One photodiode receives a proportion of the light redirected from the main optical path by a beam splitter. A second photodiode receives a proportion of the light redirected from the main optical path by the beam splitter and passing through a broadband filter. A third photodiode receives light that has been caused to interfere by an interferometric device. The ratio of the light intensities at the first and second photodiodes provide a coarse determination of wavelength, when compared to a lookup table, and the ratio of the light intensities at the first and third photodiodes provide a more exact determination of the wavelength.