A telecommunications module includes a main housing portion and a cover, the main housing portion defining a first sidewall, a front wall, a rear wall, a top wall, and a bottom wall, the cover defining a second sidewall when mounted on the main housing portion. An optical component located within the module receives an input signal from a signal input location of the housing and outputs an output signal toward a signal output location on the front wall. The telecommunications module is configured such that the signal input location can be selected to be either on the front wall or the rear wall of the main housing. The cover defines a protrusion extending from the second sidewall toward the main housing portion, the protrusion being selectively breakable to expose a recess on the front wall of the main housing portion that defines a signal input location.

A reconfigurable optical add/drop multiplexer includes N input ports, N output ports, M add ports and M drop ports. Each of the N input ports and each of the M add ports is respectively connected to one first polarizer. Each of the N output ports and each of the M drop ports is respectively connected to one second polarizer. A first end of the first polarizer is connected to a second end of the first polarizer, forming a loop including the first polarizer. A first end of the second polarizer is connected to a second end of the second polarizer, forming a loop including the second polarizer. An annular waveguide array is between a loop L.sub.Ii and a loop L.sub.Oj. A first polarizer included in the loop L.sub.Ii is connected to an i.sup.th input port. A second polarizer included in the loop L.sub.Oj is connected to a j.sup.th output port.

A wavelength selective switch and a wavelength selection method are provided, where the wavelength selective switch includes: a dual-microring resonator, including a first microring and a second microring that are connected in series, where the first microring and the second microring respectively include one annular PN junction, and a direction of the annular PN junction of the first microring is the same as that of the annular PN junction of the second microring; an electric tuning module, where a first electric port of the electric tuning module is connected to a P zone of the first microring and an N zone of the second microring, a second electric port of the electric tuning module is connected to an N zone of the first microring and a P zone of the second microring; and a thermal tuning module, configured to adjust an operating temperature of the dual-microring resonator.

Narrow linewidth multi-wavelength (MW) light sources and related methods are disclosed. Such a light source includes gain chips coupled to a wavelength combiner and reflection chip that includes phase control sections (PCSs), a wavelength division multiplexer (WDM), and a micro-ring resonator (MRR) based reflector. The WDM combines light beams received from the gain chips, via the PCSs, into a combined light beam. The MRR based reflector receives the combined light beam and generates both a reflection MW light beam and a transmission MW light beam. The WDM receives the reflection MW light beam, separates it into different wavelengths, and provides each different wavelength of light via a respective one of the PCSs to a respective one of the gain chips to self seed an internal laser cavity thereof. The transmission MW light beam is, or is used to produce, the narrow linewidth MW light produced by the light source.

Embodiments of this application disclose a spectrum processing apparatus, which includes: a port assembly, a lens assembly, a dispersive assembly, a spatial light modulator (SLM), and a reflective element. Each port in the port assembly is configured to transmit an input first light beam to a lens corresponding to the port. Each lens in the lens assembly is configured to adjust a width of the first light beam to obtain a second light beam. The reflective element is configured to reflect the second light beam to the dispersive assembly. The dispersive assembly is configured to decompose the second light beam into a plurality of sub-wavelength light beams. The reflective element is further configured to reflect the plurality of sub-wavelength light beams to the SLM. The SLM is configured to modulate the plurality of sub-wavelength light beams, and reflect at least one modulated sub-wavelength light beam to the reflective element.

Predictive management of a network buffer is contemplated. The network buffer maybe predictively managed to control packet drop based at least in part on predicted sojourn time. The predicted sojourn time may be determined to predict time needed from an arriving packet to travel through a queue of the network buffer.

Disclosed is a compact device for wavelength-division multiplexing applications. In particular, disclosed is a device that includes a housing and a core at least partially positioned within the housing. The core includes a first single fiber stub, a second single fiber stub, and at least one functional layer positioned between a first fiber of the first single fiber stub and a second fiber of the second single fiber stub. The at least one functional layer is configured to: (i) permit routing of a transmission signal of a multiplexed signal along an optical path from the first fiber stub to the second fiber stub, and (ii) prevent routing of a non-transmission signal of the multiplexed signal along the optical path from the first fiber stub to the second fiber stub. A distance between a first ferrule of the first fiber stub and a second ferrule of the second fiber stub is less than about 0.05 mm.

Disclosed is a compact device for wavelength-division multiplexing applications. In particular, disclosed is a device that includes a housing and a core at least partially positioned within the housing. The core includes a first single fiber stub, a second single fiber stub, and at least one functional layer positioned between a first fiber of the first single fiber stub and a second fiber of the second single fiber stub. The at least one functional layer is configured to: (i) permit routing of a transmission signal of a multiplexed signal along an optical path from the first fiber stub to the second fiber stub, and (ii) prevent routing of a non-transmission signal of the multiplexed signal along the optical path from the first fiber stub to the second fiber stub. A distance between a first ferrule of the first fiber stub and a second ferrule of the second fiber stub is less than about 0.05 mm.

The optical device coupleable to a waveguide to receive an optical signal from the waveguide generally has at least two optical grating devices optically coupled to one another and having corresponding spectral responses, the spectral response of at least one of said optical grating devices being tunable to adjust an amount of overlapping between the spectral responses of the at least two optical grating devices.

A wavelength selective switching device comprises a plurality of input paths for receiving optical signals, a plurality of output paths for emitting the optical signals, and a switching unit for selectively directing the optical signals from the input paths to the output paths. The switching unit comprises a reflective area adapted to be concurrently illuminated by a first optical signal from a first input path among the plurality of input paths, and by a second optical signal from a second input path among the plurality of input paths, the second input path being different from the first input path, and to concurrently direct the first optical signal to a first output path among the plurality of output paths and the second optical signal to a second output path among the plurality of output paths, the second output path being different from the first output path. Said first output path and said second output path are spatially separated by said first input path and said second input path, or vice-versa.