Abstract: Attenuators used to regulate optical signals are disclosed. According to one aspect of the present invention, an assembly including an IR source and an IR sensor is provided to sense blockage of optical signals transmitted between two collimators via a fixed common light blocker that is driven by a stepper motor. The movement of the light blocker is sensed by a sensing assembly including an IR source and IR sensor. By detecting the photocurrent from the IR sensor and a feedback circuit, the attenuation of the optical signals can be well controlled.

Abstract: An architecture for controlling a multiprocessing system to provide at least one network service to subscriber data packets transmitted in the system using a plurality of compute elements, comprising a management compute element including service set-up information for at least one service and at least one processing compute element applying said at least one network service to said data packets and communicating service set-up information with the management compute element in order to perform service specific operations on data packets. In a further embodiment, a method of controlling a processing system including a plurality of processors is disclosed.

Abstract: A network content service apparatus includes a set of compute elements adapted to perform a set of network services; and a switching fabric coupling compute elements in said set of compute elements. The set of network services includes firewall protection, Network Address Translation, Internet Protocol forwarding, bandwidth management, Secure Sockets Layer operations, Web caching, Web switching, and virtual private networking. Code operable on the compute elements enables the network services, and the compute elements are provided on blades which further include at least one input/output port.

Abstract: Designs of optical devices particularly useful for separating channels signals that are originally multiplexed are disclosed. In accordance with one design, an optical filter configured to reflect a particular channel signal is positioned to receive a multiplexed signal at a small incident angle so as to minimize residuals of other signals in the channel signal. To further increase isolation from the other channel signals, another filter is introduced to transmit only the reflected channel signal, the another filter has a frequency response reciprocal to that of the original optical filter. One of the key advantages, benefits and objects of the designs is to increase channel signals separation efficiency by increasing isolation among separated channel signals.

Abstract: A network content service apparatus includes a set of compute elements adapted to perform a set of network services; and a switching fabric coupling compute elements in said set of compute elements. The set of network services includes firewall protection, Network Address Translation, Internet Protocol forwarding, bandwidth management, Secure Sockets Layer operations, Web caching, Web switching, and virtual private networking. Code operable on the compute elements enables the network services, and the compute elements are provided on blades which further include at least one input/output port.

Abstract: A grating drive apparatus for use in a multiple-grating spectrometer is provided. The spectrometer has an entrance slit, an exit port, an optical path between the entrance slit and the exit port, and a plurality of diffraction gratings. Each of the gratings is rotatable about a respective preferred axis for selecting a wavelength during spectrometer operation. The grating drive apparatus includes a turret having a plurality of gratings mounted on it, a mechanical stop assembly, and a drive assembly. The drive assembly causes the turret to engage the stop assembly to rotate the turret and select a grating. The drive assembly also rotates the selected grating to select an operational wavelength.