Abstract: An installer for a computing device determines firstly whether or not a software package for installation has been signed. If the package is signed it is installed on the device. However, if the package is unsigned, the installer will only install the package on the device if it contains a non-null VID (vendor identity).

Abstract: Methods, apparatuses, and systems are provided for determining proximity between computing apparatuses. A method may include extracting information indicating a transmit signal strength from each of a plurality of electromagnetic transmissions sent by a plurality of second computing apparatuses and received by a first computing apparatus. The method may further include determining received signal strengths of the electromagnetic transmissions. The method may additionally include determining proximities between the first computing apparatus and each of the second computing apparatuses based at least in part upon transmit signal strengths and the received signal strengths. The method may also include generating a list listing the second computing apparatuses and providing an indication of the determined proximities of the second computing apparatuses. Corresponding apparatuses and systems are also provided.

Abstract: A computing device is operated in a manner which provides improved checking to determine whether or not an authentication certificate for a software application being loaded onto the device has been revoked. In the case of trusted certificate chains that contain no revocation information, the device checks using an AuthorityInfoAccess extension (AIA) as selected by the device. In the case of untrusted certificate chains, notably including self-signed certificates, the device is controlled so that it ignores any authentication revocation information provided with the software application and always uses information stored on the device.

Abstract: A computing device having a security model based on user permissions is provided with an ability to emulate a security model based on process capabilities by providing each executable program on the device with a separate user identity.

Abstract: A computing device is arranged to use any possible permutation of methods available to it to authenticate a user, without needing to persistently store any unencrypted data that can be used in authentication, such data only ever being held in transient memory. A user of the device is provided with their own unique common protection key (CPK) which can be used to guard or encrypt sensitive data and functionality. Each authentication method is guaranteed to return a unique consistent identification sequence (CIS) each time it is employed by any specific user. When a user registers on the device, the CIS from each authentication method is used to generate a key which in turn is used to encrypt the CPK; this E(CPK) is then stored in a table indexed by user and authentication method. Neither the CPK nor any CIS are ever kept on the device except in transient memory. When authentication is sought, the CIS for each requested method is obtained and is used to regenerate the key that can be used to decrypt the E(CPK).

Abstract: A wavelength of an optical source is monitored by first and second adjacent detectors on a common base. A bulk reflective component has first and second partially reflective surfaces that respectively direct first and second portions of energy from the source to the first and second detectors. A wavelength discriminator is positioned between the first detector and first surface. An optical isolator downstream of the reflective component prevents radiation from the source and exiting the component from being coupled to the detectors and back to the source.

Abstract: A wavelength of an optical source is monitored by first and second adjacent detectors on a common base. A bulk reflective component has first and second partially reflective surfaces that respectively direct first and second portions of energy from the source to the first and second detectors. A wavelength discriminator is positioned between the first detector and first surface. An optical isolator downstream of the reflective component prevents radiation from the source and exiting the component from being coupled to the detectors and back to the source.

Abstract: A laser located within a casing of an optoelectronic module is operated by heating the laser to an operating temperature at or above the maximum specified, operating temperature of the module casing using a heater device within the module, the laser having operating characteristics at its operating temperature that are sufficient for its required function. The heater device can be separated from the module casing by an insulating layer or by a thermal switch. The thermal switch can include a droplet of thermally conductive fluid displaceable between a first position where it provides a low thermal impedance path between the heater device and the module casing and a second position wherein a high thermal impedance path is provided between the heater device and the module casing.

Abstract: An optoelectronic assembly (300) includes a laser (102) for emitting light along a main optical path. Beam splitters (110, 114) split a proportion of light from the main optical path and the split light is guided by optical light guides (310) to a photodiode array (302). The light guides (310) are mouldable and substantially rigid and can be co fabricated as a single assembly including fiducials to facilitate positioning on a substrate (124) of the assembly (300). By having the array (302) adjacent the periphery of the substrate (124), wirebonds (308) need only be provided directly from the array (302) to a feed-through (130), and electrical tracks on the substrate and ceramic blocks for mounting the photodiodes are eliminated, as is individual placement of the ceramic blocks on the substrate.

Abstract: The slope efficiency of a laser diode is determined by temporarily adjusting a current applied to the laser and measuring a corresponding change in the average output power. Such prior art techniques require the laser modulation current average to be small to avoid impairment of transmission of data by the laser diode. An optical attenuator opposite an output of a laser diode resolves this problem by maintaining the average power emitted by the laser diode within acceptable operating limits.

Abstract: The slope efficiency of a laser diode is determined by temporarily adjusting a current applied to the laser and measuring a corresponding change in the average output power. Such prior art techniques require the laser modulation current average to be small to avoid impairment of transmission of data by the laser diode. An optical attenuator opposite an output of a laser diode resolves this problem by maintaining the average power emitted by the laser diode within acceptable operating limits.

Abstract: A laser (102) located within a casing (128) of an optoelectronic module (200) is operated by heating the laser (102) to an operating temperature at or above the maximum specified operating temperature of the module casing (128) using a heater device (202) within the module (200), the laser (102) having operating characteristics at its operating temperature that are sufficient for its required function. The heater device (202) can be separated from the module casing (128) by an insulating layer (204) or by a thermal switch. The thermal switch can include a droplet of thermally conductive fluid displaceable between a first position where it provides a low thermal impedance path between the heater device and the module casing and a second position wherein a high thermal impedance path is provided between the heater device and the module casing.

Abstract: An optoelectronic assembly (300) includes a laser (102) for emitting light along a main optical path. Beam splitters (110, 114) split a proportion of light from the main optical path and the split light is guided by optical light guides (310) to a photodiode array (302). The light guides (310) are mouldable and substantially rigid and can be co fabricated as a single assembly including fiducials to facilitate positioning on a substrate (124) of the assembly (300). By having the array (302) adjacent the periphery of the substrate (124), wirebonds (308) need only be provided directly from the array (302) to a feed-through (130), and electrical tracks on the substrate and ceramic blocks for mounting the photodiodes are eliminated, as is individual placement of the ceramic blocks on the substrate.

Abstract: An integrated variable optical attenuator and isolator assembly includes:

Abstract: Known devices for detecting wavelengths of received light require discrete components, which need to be placed with care and accurately aligned. Additionally, some known devices for detecting wavelengths have relatively large dimensions and do not lend themselves well to monolithic integration with other devices. The present invention provides a wavelength photodetector (100), for example, a p-i-n photodetector having a waveguide (110) disposed therein, the waveguide comprising a chirped Bragg grating (202) to provide wavelength selectivity. The waveguide photodetector (100) therefore generates a current linearly proportional to the wavelengths of light received. Advantageously, the waveguide photodetector can be integrally formed with other semiconductor devices and does not require precise alignment of discrete components.

Abstract: A wavelength of an optical source is monitored by first and second adjacent detectors on a common base. A bulk reflective component has first and second partially reflective surfaces that respectively direct first and second portions of energy from the source to the first and second detectors. A wavelength discriminator is positioned between the first detector and first surface. An optical isolator downstream of the reflective component prevents radiation from the source and exiting the component from being coupled to the detectors and back to the source.