129 results about "Wavelength reuse" patented technology

An integrated etched multilayer grating-based wavelength multiplexer/demultiplexer is disclosed wherein an etched multilayer grating structure is monolithically integrated within the optical waveguide stack of the multiplexer/demultiplexer to reflectively diffract an input optical beam. The multilayer grating structure is generally comprised of a series of etched diffractive elements and an etched multilayer reflector, the combined optical response of which providing the desired multiplexing/demultiplexing effect. The etched structures are generally comprised of shallow etch structures in a top surface of the multiplexer/demultiplexer waveguide stack. Monolithically integrated input and output ridge waveguides may also be provided, optionally fabricated in a same etching step as the etched multilayer grating.

Apparatus connecting electrical circuit boards (1, 2, 3, . . . N) so each board can communicate with each other. Each board has an optical circuit, which in turn has a transmitter module (T) and a receiver module (R). The transmitter module (T) has electrical to optical converters (11B) for converting electrical signals into optical signals, a wavelength multiplexer (12) for multiplexing the optical signals into a single optical waveguide (12A), and an optical splitter (13) for dividing the multiplexed signal into a plurality of identical signals for transmission to each of the receiver modules (R). The receiver module (R) has an optical selector (14) for selecting signals from the transmission modules (T), a wavelength demultiplexer (21) for demultiplexing the selected signal into signals each of a different wavelength (lambd1 . . . lambdn), and optical to electrical converters (22B) for converting each of the signals of different wavelengths into an electrical signal.

Provided is a passive optical network (PON) based on a reflective semiconductor optical amplifier (RSOA). In the PON, seed-light-injection RSOAs are used in an optical line terminal (OLT) to achieve the color-less management of the wavelengths of OLT optic sources, and wavelength reuse RSOAs are used to achieve the color-less management of the wavelengths of ONTs. Therefore, problems related to ONT wavelength management can be eliminated by the wavelength reuse RSOAs, and problems related to OLT wavelength management can be eliminated by the seed-light-injection RSOAs.

A multimode wavelength multiplexing optical transceiver has: a plurality of light emitting elements that emit single-mode lights with wavelengths different from each other; and a multimode waveguide module that is operable to multiplex the emitted single-mode lights into a multimode light. The multimode waveguide module is a step-index type multimode waveguide module that is operable to reduce a low-order mode component of the multimode light.

A receiver optical module to facilitate the assembling is disclosed. The receiver optical module includes an intermediate assembly including the optical de-multiplexer and the optical reflector each mounted on the upper base, and the lens and the PD mounted on the sub-mount. The latter assembly is mounted on the bottom of the housing; while, the former assembly is also mounted on the bottom through the lower base. The upper base is apart from the bottom and extends in parallel to the bottom to form a surplus space where the amplifying circuit is mounted.

The invention is suitable for the optical communication field and discloses a multi-wavelength multiplexing/demultiplexing parallel light receiving/emitting component. Four laser emitting chips or detector receiving chips arranged on a PCB circuit board are located on the same straight line; four collimating lenses are respectively located above the four laser emitting chips or detector receiving chips, and top light spots are aligned to the centers of photosensitive surfaces of the four detector receiving chips or the four laser emitting chips; four wavelength division multiplexing/demultiplexing optical filters are respectively arranged above the four collimating lenses and parallel to each other, the reflecting surfaces face to the downside, and the angle between each reflecting surface and the PCB circuit board is 45 degrees; a fifth collimating lens is located at one side of the reflecting surface of each wavelength division multiplexing/demultiplexing optical filter, and the optical paths between the fifth collimating lenses and the wavelength division multiplexing/demultiplexing optical filters are vertical to the optical paths between the wavelength division multiplexing/demultiplexing optical filters and laser emitting chips or detector receiving chips. Several channels only need one optical fiber to perform communication transmission, and the optical fiber cost is greatly saved.

The present invention provides a wavelength multiplexer/demultiplexer comprising a Mach-Zehnder interferometer and an arrayed waveguide diffraction grating, the wavelength multiplexer/demultiplexer having a simple configuration and being capable of reducing the degradation in the temperature compensation characteristics of a temperature compensation material provided in the Mach-Zehnder interferometer or the peeling-off of the temperature compensation material, and a method of manufacturing the same. A wavelength multiplexer/demultiplexer comprises an AWG including two separated slab waveguides and an MZI including two arm waveguides. A temperature compensation groove is formed in the two arm waveguides, wherein in a space between the temperature compensation groove, and two separated slab waveguides, a compensation material, the refractive index matching that of the AWG or Mach-Zehnder interferometer, the compensation material having a temperature dependence coefficient with a sign different from that of the temperature dependence coefficient of the waveguide core and having plasticity or fluidity, is filled.

A stacked waveguide assembly can have multiple waveguide stacks. Each waveguide stack can include a plurality of waveguides, where a first waveguide stack may be associated with a first subcolor of each of three different colors, and a second waveguide stack may be associated with a second subcolor of each of the three different colors. For example, the first stack of waveguides can incouple blue, green, and red light at 440 nm, 520 nm, and 650 nm, respectively. The second stack of waveguides can incouple blue, green, and red light at 450 nm, 530 nm, and 660 nm, respectively.

A wavelength selective switch device includes an incidence part where wavelength multiplexed light made of light of a plurality of wavelengths enters, an exit part that includes a plurality of fiber that outputs light of a wavelength selected from a signal in which wavelength multiplexed light that entered from the incidence part enters, a polarization diversity part that separates incidence light that entered the incidence part according to polarization components of the incidence light to make first and second optical beams, a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength, and a wavelength dispersion and synthesis element that spatially disperses incidence light according to a wavelength of the incidence light and multiplexes the spatially dispersed reflected light according to the wavelength.

In an optical device, each of a plurality of radiation sources generates a separate different wavelength output signal to a wavelength locking device wherein a grating device receives the separate wavelength output signals from the plurality of radiation sources. The grating device generates a multiplexed wavelength output signal at a zero diffraction order output port thereof, and resolves separate symmetric wavelength+δ and wavelength−δ output signals at separate predetermined locations within at least one non-zero diffraction order thereof for each of the radiation sources. Each of a plurality of radiation detectors is coupled to receive a separate one of the symmetric wavelength+δ and wavelength−δ output signals and generate an output signal representing the magnitude of the received wavelength output signal. A control device is responsive to output signals from each pair of radiation detectors coupled to receive the separate symmetric wavelength+δ and wavelength−δ output signals from a specified predetermined radiation source for generating an output control signal appropriate to that radiation source for locking the wavelength thereof.

A method includes generating an optical millimeter wave signal for modulation of a first data signal, and deriving from the generated optical millimeter wave signal a subsequent light source for modulation of a second data signal. More specifically the generating includes modulating a light wave to a multiple of a frequency of an oscillating signal. Alternatively, the generating includes modulating a data signal mixed with an oscillating signal to a multiple of a frequency of the oscillating signal. The deriving includes modulating a frequency component filtered from a data modulation of the generated optical millimeter wave signal.

A porous silicon filter for wavelength multiplexing and de-multiplexing. Preferred embodiments include rugate-type porous silicon filters with pores having continuously varying widths with pore depth an optical cross connect switch. In other preferred embodiments, the pores are filled with a material that changes index of refraction with changes in applied voltage, current or temperature. Important applications of these porous silicon filters are for multiplexing and de-multiplexing in fiber optic communication systems. For example, a preferred embodiment is an all optical fiber optic switch utilizing these filters.

A method and apparatus for implementing an RF photonic transversal filter that utilizes tap apodization and wavelength reuse to obtain a high side lobe suppression together with narrow and configurable passbands. Several taps are obtained from one wavelength by using dispersive optical delay lines such as chirped fiber gratings that introduce a delay between successive wavelengths. A selected subset of the input wavelengths is utilized to generate multiple taps per wavelength. Some of the taps are apodized to generate various filter transfer functions that yield a high side lobe suppression ratio.

A phased antenna array includes an array of antenna elements, and an electro-optic (EO) readout circuit coupled to the array of antenna elements. The EU readout circuit includes an optical source including a mode locked laser (MLL) configured to generate an optical carrier signal having beam carrier wavelengths, an EO modulator configured to modulate a signal from an antenna element based upon the optical carrier signal, a first WDM coupled downstream from the EO modulator, and optical-to-electrical converters coupled downstream from the first WDM. The first WDM is configured to multiplex each modulated beam carrier wavelength to a respective optical-to-electrical converter.

This invention discloses a method and a system for generating and re-using full light millimeter waves of full duplex communication and re-using wave lengths in the Radio-on-Fiber ROF communication system, which applies a carier suppression method by double pole modulator and filters by an optical filter to separate two vertical modes of a carrier suppression signal, one of which is modulated in its baseband signals and couples to the other one un-modulated to generate optical millimeter waves to simplify, stabilize the structure of the central station at low cost, and an optical filter is used in the base station to filter out the vertical mode with un-modulated signals as the optical carrier of up link and realizes repeatedly using the wavelength in down-link in the up link so that light source is not used any more in the base station and the structure is simple and cost, besides, a ROF system is provided for realizing generating light millimeter waves and re-using up link wavelength.

Disclosed is a wavelength multi/demultiplexer for separating two wavelength bands with a narrow wavelength spacing. A dielectric multilayer filter is provided in an intersection portion where two optical waveguides intersect each other and separates incident light to the dielectric multilayer filter to transmitted light and reflected light. Here, the distance X from the multilayer surface on the light-incident side of the dielectric multilayer to the central intersection point of the two intersecting optical waveguides is arranged to satisfy 0≦X≦d/2 (where “d” represents the thickness of the dielectric multilayer). With this configuration, a multi/demultiplexer can be realized that shows good wavelength response without spectral degradation even for two wavelengths having narrow wavelength spacing.

The invention discloses an ROADM node, an optical wavelength correction frequency shifter and an implementation method. The wavelength correction frequency shifter comprises a sawtooth wave electric signal generator and an electro-optic phase modulator, wherein the sawtooth wave electric signal generator produces continuous sawtooth wave electric signals with the repetition frequency of F, which serve as driving electric signals, and the electro-optic phase modulator loads driving electric signals to conduct frequency shift delta fi on the central wavelength of input optical signals, so that the central wavelength lambada i of input optical signals is close to the expected central wavelength lambada i-1, and c represents the velocity of light. According to the ROADM node, the optical wavelength correction frequency shifter and the implementation method, the central wavelength of input optical signals is close to the designed central wavelength of an ROADM through correction of the central wavelength of input optical signals, so that the effective bandwidth loss of the ROADM, which is caused by the multistage filtering cascaded filtering function, is reduced, an all-optical method is used for correcting the wavelength of optical signals, and the implementation method is applicable to ROADM nodes of any wavelength multiplexing wavelength division multiplex (WDM) optical networks of various transmission rates.

A method and system for maximizing wavelength reuse in an optically protected wavelength-division-multiplexed (WDM) network, the WDM network supporting a plurality of service connections, includes associating service connections supported by non-overlapping paths to form respective service channel groups, and for each service channel group, assigning at least one common wavelength channel for establishing the service connections. In addition, for each of said groups, at least one common wavelength channel is assigned for establishing a shared protection path for the service connections of each of said groups. In addition, the wavelength channels assigned for establishing the shared protection paths for each of the groups may be used for providing service connections for the WDM network when not in use as shared protection paths. However such provisional service connections are dropped when the wavelength channels are needed to establish shared protection paths. Such provisional service connections may be offered at reduced cost.

The subject to be attained by the disclosed technique is to provide an optical unit less expensive than conventional like optical units and having a wavelength multiplexer and optical waveguides. For achieving the above subject there is provided a wavelength multiplexer wherein a light combining/branching section is constituted by a multi-mode interference type optical waveguide, and an incident-side optical waveguide and a reflection-side optical waveguide are spaced a predetermined distance from each other at their connections to the multi-mode interference type optical waveguide. An optical filter is installed in the multi-mode interference type optical waveguide and a multi-mode interference is set so that a peak in a light intensity distribution is formed in the vicinity of an inlet of each of an exit-side optical waveguide and the reflection-side optical waveguide.

A method and apparatus is described for controlling the attenuation of multiple wavelengths signals propagating in an optical fiber, that may have a time-dependent power in each signal, to provide an output signal having a desired attenuated power in each of the multiple signals. An equalizer may be used that has various optical elements to focus and disperse light, such as a concave diffraction grating and a modulator array having modulators disposed on a concave surface. The equalizer may also be coupled to various components such as a circulator or thermally expanded core fibers.