In the wavelength selective switch provided in the present invention, at least one optical element is successively arranged in the wavelength selective switch according to a sequence of processing optical signals. The at least one optical element receives a service optical signal from a service laser, receives a monitoring optical signal from a monitoring laser, and performs same optical signal processing on the service optical signal and the monitoring optical signal according to a processing function of the at least one optical element, where a wavelength of the service optical signal and a wavelength of the monitoring optical signal are different. A service optical signal processed by the at least one optical element and a monitoring optical signal processed by at least one optical element are output, where the monitoring optical signal processed by the at least one optical element is used for monitoring performance of the wavelength selective switch.

Methods and apparatus for furcating fiber optic cables are provided. In some embodiments, a molded furcation tube array is generated by compressing rearward end portions of a plurality of furcation tubes together, and heating at least a portion of the rearward end portions to form a molded portion of the furcation tube array. Reinforcing filaments can be bonded into and/or throughout the molded portion. The molded portion can have internal chambers in communication with separate furcation tubes of the furcation tube array, in which optic fibers can be slidably retained, and the molded portion can be fixedly coupled to a housing, which in turn, can be coupled to a cable trunkline. Optic fibers can piston or slide longitudinally within the trunkline housing and molded portion.

In various embodiments, wavelength beam combining laser systems incorporate optical cross-coupling mitigation systems and/or engineered partially reflective output couplers in order to reduce or substantially eliminate unwanted back-reflection of stray light.

In various embodiments, wavelength beam combining laser systems incorporate optical cross-coupling mitigation systems and/or engineered partially reflective output couplers in order to reduce or substantially eliminate unwanted back-reflection of stray light.

A self-fit optical filter includes a dual fiber collimator, a diffraction grating for spatially dispersing the input light beam into a plurality of sub-beams, a cylindrical lens for focusing each of the sub-beams at a saturable absorber which becomes saturated dependent on intensity of light, and a reflector for reflecting the sub-beams back along their optical paths. A method of filtering includes: demultiplexing an input beam into a plurality of sub-beams having distinct center wavelengths, at least partially absorbing one or more of the sub-beams by using a saturable absorber while allowing other sub-beams to pass through, substantially unattenuated, and multiplexing the sub-beams into an output optical signal.

Embodiments of present invention provide a digital dispersion compensation module. The digital dispersion compensation module includes a multi-port optical circulator and a plurality of dispersion compensation units connected to the multi-port optical circulator, wherein at least one of the plurality of dispersion compensation units includes a first and a second reflectively terminated element and an optical switch being capable of selectively connecting to one of the first and second reflectively terminated elements, and wherein the at least one of the plurality of dispersion compensation units is adapted to provide a substantially zero dispersion to an optical signal, coming from the multi-port optical circulator, when the optical switch connects to the first reflectively terminated element and is adapted to provide a non-zero dispersion to the optical signal when the optical switch connects to the second reflectively terminated element.

In the wavelength selective switch provided in the present invention, at least one optical element is successively arranged in the wavelength selective switch according to a sequence of processing optical signals. The at least one optical element receives a service optical signal from a service laser, receives a monitoring optical signal from a monitoring laser, and performs same optical signal processing on the service optical signal and the monitoring optical signal according to a processing function of the at least one optical element, where a wavelength of the service optical signal and a wavelength of the monitoring optical signal are different. A service optical signal processed by the at least one optical element and a monitoring optical signal processed by at least one optical element are output, where the monitoring optical signal processed by the at least one optical element is used for monitoring performance of the wavelength selective switch.

Apparatus include a first optical fiber including a core situated to propagate a signal beam at a signal wavelength and an unwanted stimulated Raman scattering (SRS) beam at an SRS wavelength associated with the signal wavelength, and a fiber Bragg grating (FBG) situated in a core of a second optical fiber optically coupled to the core of the first optical fiber, the FBG having a selected grating reflectivity associated with the SRS wavelength and being situated to reflect the SRS beam back along the core of the second optical fiber and to reduce a damage associated with propagation of the SRS beam to power sensitive laser system components optically coupled to the second optical fiber. Methods are also disclosed.

An object of the present disclosure is to provide an optical side input/output circuit for allowing light for being input into or output from a side surface of an optical fiber with high efficiency.

The present disclosure is an optical side input/output circuit including: a tap unit in which a tap waveguide is formed for allowing light for propagation through a core of an optical fiber for being input into or output from a side surface of the optical fiber; and a refractive index matching unit, having a refractive index higher than a refractive index of the tap waveguide, on the side surface of the optical fiber where the light is allowed for being input or output by the tap waveguide.

The invention relates to an optical fiber mounted photonic integrated circuit device, wherein the tolerance for positioning in terms of the coupling between the single mode optical fibers and the optical waveguides provided on the photonic integrated circuit device is increased. An optical waveguide core group is provided in such a manner where a plurality of optical waveguide cores having a portion that is tapered in the direction of the width within a plane are aligned parallel to each other at intervals that allow for mutual directional coupling and that are narrower than the width of the core of the single mode optical fiber, and the inclined connection end surface of the single mode optical fiber and the upper surface of an end portion of the optical waveguide cores face each other for coupling.