Abstract: A wavelength blocker including an input port for launching an input beam of light, first dispersing means for dispersing the input beam of light according to wavelength, an array of independently addressable elements for selectively blocking a portion of the dispersed beam of light, second dispersing means for receiving the passed dispersed beam of light and for producing a single multiplexed beam of light therefrom, and an output port for transmitting a modified output beam of light. The array of independently addressable elements are designed such that the wavelength blocker is capable of blocking a variable number of non-consecutive channels without significantly affecting the unblocked channels.

Abstract: A wavelength blocker including an input port for launching an input beam of light, first dispersing means for dispersing the input beam of light according to wavelength, an array of independently addressable elements for selectively blocking a portion of the dispersed beam of light, second dispersing means for receiving the passed dispersed beam of light and for producing a single multiplexed beam of light therefrom, and an output port for transmitting a modified output beam of light. The array of independently addressable elements are designed such that the wavelength blocker is capable of blocking a variable number of non-consecutive channels without significantly affecting the unblocked channels.

Abstract: A system for wavelength locking i.e. for maintaining a frequency of an optical signal to within predetermined limits has means for splitting part of the controlled optical signal into at least three sub-beams of which one is a reference beam and two others are provided to an optical element having a periodic output response and to a filter having a monotonic output response. The three detected outputs are analyzed and processed to determine accurately the wavelength of the optical signal and to produce a correcting signal if it is not within the predetermined limits.

Abstract: The present invention relates to a circuit for monitoring optical signals in a multiple channel system. A tunable band pass filter receives and input signal comprising multiple channels each having a different wavelength and predetermined channel spacing. Output from the tunable filter is directed to a second filter having a periodic response with wavelength, such as an etalon. The response is designed to block wavelengths of light corresponding to the channels, permitting noise in the inter-channel space to be measured by a detector. A reference circuit launches light from a broad band source through a Bragg grating into the tunable filter. The Bragg grating reflects a known reference wavelength. Light which passes from the reference source through the tunable filter is also passed through the second filter to a detector. When a notch is detected by the reference detector, the tunable filter is known to be tuned to the reference wavelength.

Abstract: A variable, hybrid optical attenuator has a flexure member which consists of a bridge portion joining two prongs which are flexibly movable relative to the bridge portion. A mirror is mounted on the bridge portion. The prongs are each connected to an actuator which can expand or contract in response to a control signal applied thereto. The control signal may be heat, an electric field, a magnetic field or, preferably, a combination thereof. The attenuator is positioned opposite a pair of optical waveguides so that an input optical signal from an input waveguide is incident on the mirror and, upon reflection, is received by the second waveguide. Attenuation of the transmission is effected by controlled tilting of the mirror caused by appropriate control signals, single or in combination, applied to one or both of the actuators.