Wavelength division multiplexing (WDM) has enabled telecommunication service providers to fully exploit the transmission capacity of optical fibers. State of the art systems in long-haul networks now have aggregated capacities of terabits per second. Moreover, by providing multiple independent multi-gigabit channels, WDM technologies offer service providers with a straight forward way to build networks and expand networks to support multiple clients with different requirements. In order to reduce costs, enhance network flexibility, reduce spares, and provide re-configurability many service providers have migrated away from fixed wavelength transmitters, receivers, and transceivers, to wavelength tunable transmitters, receivers, and transceivers as well as wavelength dependent add-drop multiplexer, space switches etc. However, to meet the competing demands for improved performance, increased integration, reduced footprint, reduced power consumption, increased flexibility, re-configurability, and lower cost it is desirable to exploit/adopt monolithic optical circuit technologies, hybrid optoelectronic integration, and microelectromechanical systems (MEMS).

An optical filter includes a spectroscopic element configured to disperse input light, and emit the dispersed input light as spectrum light; and an optical fiber including an end face having a recess, a core having a first face in contact with a bottom of the recess and a second face sandwiched between the first face and a circumference end of the recess, and a clad surrounding the core, wherein in the optical fiber, the recess is irradiated with the spectrum light, the second face is inclined such that a second portion incident from the second face to the core out of the irradiated spectrum light is emitted to the clad, and a first portion incident from the first face to the core out of the irradiated spectrum light is outputted.

An object of the present invention is to provide a core position recognition method, a connection method, and a connection apparatus that can simplify connection operations, and reduce rotational displacement and positional displacement. The connection apparatus according to the present invention includes a function capable of acquiring the rotation amount of an MCF during the bonding/fixing step. Specifically, the connection apparatus of the present invention uses an MCF with lines drawn on a side surface thereof, thereby recognizing the rotation amount of the MCF from the side surface, and calculating the absolute positions of the cores. The connection apparatus according to the present invention can recognize the absolute position s of the cores from a side image of an MCF in a state in which the MCF has been rotated. By forming a waveguide on a glass substrate serving as a connection destination so as to match the absolute positions of the cores, the rotational and positional displacements of the MCF can be eliminated, thus making it possible to reduce the connection loss.

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.

The present invention provides a wavelength division multiplexing/demultiplexing optical transceiving assembly based on a diffraction grating, which is an uplink optical emitting unit and a downlink optical receiving unit that comprise a laser chip array, a light receiving detector array, a first fast axis collimating lens, a second fast axis collimating lens, a first slow axis collimating lens, a diffraction grating, a slow axis focusing lens, a second slow axis collimating lens, an optical isolator, a coupling output lens, a coupling input lens, a coupling outputting optical fiber and a coupling inputting optical fiber. The wavelength division multiplexing/demultiplexing optical transceiving assembly solves the technical problem of sharing a diffraction grating to realize a wavelength division multiplexing/demultiplexing function, achieves the beneficial effects of better diffraction grating filtering property, smaller light path coupling loss and insertion loss correlative with wavelength, larger independent optical element sizes, and simpler assembly process, and is more suitable for manufacturing a multi-channel wavelength division multiplexing/demultiplexing optical transceiving assembly.

A wavelength division multiplexer is disclosed. The wavelength division multiplexer may include an input waveguide, in which a plurality of Bragg gratings for separating multiplexed optical signals into respective optical signals are provided, and a plurality of output waveguides connected to the input waveguide and configured to receive the optical signals separated by the plurality of Bragg gratings. The plurality of Bragg gratings may include a first Bragg grating including first protrusions each having a first width, and a second Bragg grating including second protrusions each having a second width larger than the first width. Each of the first and second protrusions may include a curved side surface, to which a corresponding one of the optical signals is incident.

Wavelength division multiplexing (WDM) has enabled telecommunication service providers to fully exploit the transmission capacity of optical fibers. State of the art systems in long-haul networks now have aggregated capacities of terabits per second. Moreover, by providing multiple independent multi-gigabit channels, WDM technologies offer service providers with a straight forward way to build networks and expand networks to support multiple clients with different requirements. In order to reduce costs, enhance network flexibility, reduce spares, and provide re-configurability many service providers have migrated away from fixed wavelength transmitters, receivers, and transceivers, to wavelength tunable transmitters, receivers, and transceivers as well as wavelength dependent add-drop multiplexer, space switches etc. However, to meet the competing demands for improved performance, increased integration, reduced footprint, reduced power consumption, increased flexibility, re-configurability, and lower cost it is desirable to exploit/adopt monolithic optical circuit technologies, hybrid optoelectronic integration, and microelectromechanical systems (MEMS).

The present invention provides a wavelength division multiplexing/demultiplexing optical transceiving assembly based on a diffraction grating, which is an uplink optical emitting unit and a downlink optical receiving unit that comprise a laser chip array, a light receiving detector array, a first fast axis collimating lens, a second fast axis collimating lens, a first slow axis collimating lens, a diffraction grating, a slow axis focusing lens, a second slow axis collimating lens, an optical isolator, a coupling output lens, a coupling input lens, a coupling outputting optical fiber and a coupling inputting optical fiber. The wavelength division multiplexing/demultiplexing optical transceiving assembly solves the technical problem of sharing a diffraction grating to realize a wavelength division multiplexing/demultiplexing function, achieves the beneficial effects of better diffraction grating filtering property, smaller light path coupling loss and insertion loss correlative with wavelength, larger independent optical element sizes, and simpler assembly process, and is more suitable for manufacturing a multi-channel wavelength division multiplexing/demultiplexing optical transceiving assembly.

A beam-splitting apparatus arranged to receive an input radiation beam and split the input radiation beam into a plurality of output radiation beams. The beam-splitting apparatus comprising a plurality of reflective diffraction gratings arranged to receive a radiation beam and configured to form a diffraction pattern comprising a plurality of diffraction orders, at least some of the reflective diffraction gratings being arranged to receive a 0.sup.th diffraction order formed at another of the reflective diffraction gratings. The reflective diffraction gratings are arranged such that the optical path of each output radiation beam includes no more than one instance of a diffraction order which is not a 0.sup.th diffraction order.

A compact wavelength dispersing device and a wavelength selective optical switch based on the wavelength dispersing device is described. The wavelength dispersing device has a folding mirror that folds the optical path at least three times. A focal length of a focusing coupler of the device is reduced and the NA is increased, while the increased optical aberrations are mitigated by using an optional coma-compensating wedge. A double-pass arrangement for a transmission diffraction grating allows further focal length and overall size reduction due to increased angular dispersion.