Partially tinted flexigrid wavelength-dividing multiplexer / demultiplexer

Abstract

To provide a wavelength division multiplex apparatus and optical modules in which a layer of arrayed waveguides is used to extend the number of ports of wavelength selective switches used in multiplexing and / or demultiplexing optical signals transported over an optical network.SOLUTION: An apparatus 100 includes: optical modules 108; and a wavelength selective switch (WSS) 112, a contentionless WSS 116 and / or a colorless splitter / combiner 120. The apparatus is coupled to transponders 104, and functions as a wavelength division multiplexer / demultiplexer to multiplex or demultiplex optical signals that are received from or sent to the transponders 104. In the multiplex or addition direction, each optical module receives optical data signals from a transponder, combines the received signal into an optical signal 128, and transmits it via a WSS or combiner over a transport fiber pair 132 to far-end or remotely located systems, apparatuses or equipment.SELECTED DRAWING: Figure 1

Description

Background Art

[0001] Wavelength division multiplexing (WDM) technology enables data transmission using multiple wavelengths of light through an optical fiber medium where each wavelength forms a different channel. More specifically, optical signals at different wavelengths (colors) are multiplexed onto a single optical fiber. This allows more data to be transmitted through a single optical fiber, and as a result, typically increases the capacity of an optical data transmission network. WDM systems are generally considered to be of two types: coarse WDM (CWDM) and dense WDM (DWDM). A CWDM system is typically considered to be a system that uses less than 8 active wavelengths per fiber. A DWDM system is typically considered to be a system that uses more than 8 active wavelengths per fiber. DWDM systems support optical data rates of hundreds of gigabits per second (Gb / s) and even terabits per second (Tb / s). These higher optical data rates can be provided through a flexible grid pattern (“flexgrid”) where different optical signals have different bandwidths or spectral widths. In practice, the flexgrid allows each wavelength of an optical signal to be defined as having an individual spectral width.

[0002] The multiplexing and demultiplexing of multiple optical signals can be achieved using different optical technologies including, but not limited to, wavelength selective switches (WSSs), arrayed waveguide gratings (AWGs), and passive colorless splitters / combiners. In the case of WSS-based and AWG-based architectures, a single WSS device or AWG device is typically used to provide the multiplexing / demultiplexing capability to cover the transmission spectrum of an optical communication link. A WSS enables flexible routing of optical signals on a WDM network. For example, a WSS can route multiple wavelengths on a common port to any one of several multi-wavelength ports. A WSS typically has a limited number of ports. A layer of passive colorless optical splitters / combiners can be used to increase the number of effective ports on a WSS.

[0003] AWGs are used in transmitters to couple channels of different wavelengths into a single optical fiber. AWGs are also used in receivers to separate individual channels. [Overview of the project]

[0004] The disclosed technology relates to a WDM node that enables efficient multiplexing or demultiplexing of multiple optical signals with different bandwidths, such as providing flexigrid functionality, while mitigating or avoiding scaling insertion loss with the number of ports. For example, the disclosed technology may take the form of an AWG-based WDM module or submodule, each functioning to multiplex and / or demultiplex one or more wavelengths or channels. In practice, layers of AWG are used to scale the number of ports used when multiplexing and / or demultiplexing optical signals transmitted over an optical network. The insertion loss of the AWG does not scale with the number of ports. Thus, layers of AWG enable flexigrid functionality while mitigating the loss scaling with the number of ports. In contrast, the insertion loss of a colorless optical splitter / combiner typically scales with the number of ports, which can create power budget challenges for some optical transceivers. Embodiments of the disclosed technology mitigate such losses.

[0005] Embodiments of the disclosed technology may include apparatus, systems, optical modules(s) or processes for wavelength division multiplexing and / or demultiplexing of optical signals. For example, the disclosed technology includes a plurality of optical modules, each optical module having a first array waveguide grating, the first array waveguide grating having a first output port and a plurality of first input ports, each of the plurality of first input ports being configured to receive an optical data signal from one of a plurality of transponders for transmission on a transmission fiber, and the first output port outputting a coupled signal formed from the optical data signals received from the plurality of transponders, the plurality of optical modules being configured such that spectrally adjacent optical signals are mapped to corresponding first input ports on different modules of the plurality of optical modules, and each optical module having an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive a coupled signal from a first output port of the first array waveguide grating, and including a wavelength division multiplexing apparatus.

[0006] According to this embodiment of the disclosed technology, the apparatus may include a wavelength selective switch having a plurality of multi-wavelength ports and one common port, the common port having a common optical signal formed from the optical signals input to the plurality of multi-wavelength ports, each multi-wavelength port being associated with the output of one optical amplifier of an optical module, and the common port being coupled to a transmission fiber. The apparatus may further include a non-contour wavelength selective switch coupled between the plurality of multi-wavelength ports of the wavelength selective switch and the output of the optical amplifier of each optical module. Furthermore, the plurality of optical modules includes N optical modules, and the plurality of multi-wavelength ports includes N multi-wavelength ports, where N is an integer value greater than or equal to 2. Furthermore, the plurality of first input ports includes M first input ports, where M is an integer value greater than 2 and equal to N.

[0007] Furthermore, according to this embodiment of the disclosed technology, each of the plurality of optical modules has at least two first array waveguides coupled to two or more of the plurality of first input ports. Furthermore, the optical data signals received at each of the plurality of first input ports from each of the plurality of transponders are of different wavelengths. Moreover, spectrally adjacent optical signals include optical signals having a center wavelength within a predetermined continuous spectral bandwidth, and the center wavelength is adjacent to another center wavelength within the predetermined continuous spectral bandwidth.

[0008] Furthermore, according to this embodiment of the disclosed technology, each of the plurality of optical modules includes a second array waveguide grid, each including a plurality of output ports configured to provide a plurality of transponders with a transmission data signal received on a transmission fiber. Furthermore, the second array waveguide grid includes a second input port that receives the transmission data signal and separates the transmission data signal into individual received signals for each of the plurality of output ports. Furthermore, the second input port is coupled to a plurality of multi-wavelength ports of a wavelength-selective switch. Furthermore, the plurality of output ports are equivalent to a plurality of first input ports of the first array waveguide grid.

[0009] Furthermore, according to this embodiment of the disclosed technology, the apparatus includes a colorless splitter / combiner having a plurality of colorless input ports and one common port, wherein the common port has a common optical signal formed from optical signals input to a plurality of multi-wavelength ports, one of each colorless input port is associated with the output of one optical amplifier of an optical module, and the common port is coupled to a transmission fiber.

[0010] Another aspect of the disclosed technology is an optical module for a wavelength division multiplexer or demultiplexer, comprising a first array waveguide grid, the first array waveguide grid comprising one first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of optical transponders for transmission on a transmission fiber, and the first output port outputting a coupled signal formed from the optical data signals received from the plurality of transponders, and the first array waveguide grid, An optical module comprising a first array waveguide grating having one first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of optical transponders for transmission in a transmission fiber, and the first output port outputting a coupled signal formed from the optical data signals received from the plurality of transponders; and an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive a coupled signal from the first output port of the first array waveguide grating.

[0011] According to this embodiment of the disclosed technology, the optical module may further include a second array waveguide grid, which includes a plurality of output ports configured to provide a plurality of optical transponders with a transmission data signal received on a transmission fiber. Furthermore, the second array waveguide grid includes a second input port that receives the transmission data signal and separates the transmission data signal into individual received signals for each of the plurality of output ports. Furthermore, the second input port is coupled to a plurality of multi-wavelength ports of a wavelength-selective switch. Moreover, the plurality of output ports are equivalent to a plurality of first input ports of the first array waveguide grid.

[0012] Another aspect of the disclosed technology is a plurality of transponders, a transmission fiber, and a plurality of optical modules, each optical module having a first array waveguide grating, the first array waveguide grating including one first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of the plurality of transponders for transmission on the transmission fiber, the first output port outputting a coupled signal formed from the optical data signals received from the plurality of transponders, and the plurality of optical modules, each optical module having the first array waveguide grating The system includes a first array waveguide grid, which includes one first output port and a plurality of first input ports, each of which is configured to receive an optical data signal from one of a plurality of transponders for transmission over a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders, and each optical module has an optical amplifier having an output and an input, the input of which is coupled to receive the coupled signal from the first output port of the first array waveguide grid.

[0013] Another aspect of the disclosed technology includes an apparatus, optical module, or system that performs the process of mapping spectrally adjacent optical signals received from a transponder to corresponding first input ports on different optical modules of a plurality of wavelength division submultiplexing optical modules. [Brief explanation of the drawing]

[0014] [Figure 1] An exemplary apparatus or system according to one aspect of the disclosed technology is shown. [Figure 2] An example of an optical signal occupying a portion of the optical spectrum using the disclosed technology is shown. [Figure 3] An exemplary apparatus or system according to one aspect of the disclosed technology is shown. [Figure 4] An exemplary apparatus or system according to one aspect of the disclosed technology is shown. [Figure 5]An example of an optical signal occupying a portion of the optical spectrum using the disclosed technology is shown. [Modes for carrying out the invention]

[0015] Figure 1 shows an example of an apparatus or system 100 according to one aspect of the disclosed technology. Apparatus 100 includes an optical module 108 and different configurations including a wavelength selective switch (WSS) 112, a non-conflicting WSS 116, and / or a colorless splitter / combiner 120. Apparatus 100 is coupled to a transponder 104. Apparatus 100 functions as a wavelength division multiplexer / demultiplexer for multiplexing or demultiplexing optical signals it receives from or transmits to the transponder 104. In some examples, the transponder 104 may be included as part of apparatus 100.

[0016] In the multiplexing or addition direction, each optical module 108 functions to receive an optical data signal from the transponder 104 and to combine the signal received by the transponder 104 into an optical signal 128. The optical signals 128 from each optical module 108 are then provided to a WSS 112, a non-conflicting WSS 116, or a colorless splitter / combiner 120 for transmission to a far-end or remotely located system, device, or equipment via the transmission fiber pair 132. For example, the system, device, or equipment may be located in a data center that also houses the source device 100, or in another data center at a different location coupled to the fiber pair 132, and may act as a destination or source for data transmitted over a network including the fiber pair 132. Networks including inter-campus communication between neighboring data centers, including communication over intercontinental underwater transmission fiber, may vary in size. As will be further described below, the optical module 108, and therefore the apparatus or system 100, can be adapted to support different applications by configuring the components that make up the optical module and how the optical module is coupled to the fiber pair.

[0017] Each fiber pair contains two fibers, one for each direction of transmission. The optical module 108 is coupled via the optical fiber pairs 135 and 139 to the transponder 104 and to the WSS 112, the uncontested WSS 116, or the colorless splitter / combiner 120.

[0018] In the demultiplexing direction, each optical module 108 functions to separate the optical signals 128 it receives from WSS 112, the uncontested WSS 116, or the colorless splitter / combiner 120 and provide the optical data signals to the transponder 104.

[0019] As shown in the figure, the transponder 104 includes both a transmitter element (Tx) and a receiver element (Rx). Thus, the transponder functions to transmit and receive optical data signals, respectively, for transmission over fiber pair 135. In the example in Figure 1, for the sake of simplicity, each optical module 108 is shown communicating with one transponder. However, in other examples, and in more typical practical applications, each optical module 108 would communicate with multiple transponders 104 via ports 160, 162 of the optical module 108. Each of the multiple transponders communicating with a given optical module 108 would communicate using signals at different wavelengths and possibly with different bandwidths, as will be further described below. The transponder 104 would also communicate with one or more other systems, such as a host system, which would function as a data source and data sink for the information carried by the optical data signals. The connections to those systems are not shown for simplicity, but typically involve electrical connections to information carrier signals, such as baseband signals. The wavelength of a transponder is usually tunable over a range surrounding the central wavelength.

[0020] Each of the optical modules 108 includes a first array waveguide analysis grid (AWG) 170 and a second AWG 174. Each AWG 170 has multiple input ports 1601-160 Mand one output port 176. The AWG 174 includes one input port 179 and a plurality of output ports 1621 to 162 M and. The AWG 170 and the AWG 174 each function as a colored combiner and splitter, and can be regarded functionally as a sub-multiplexer module or a sub-demultiplexer module. Specifically, the input port 160 is configured as an input channel, and each input channel accepts only light within a specific wavelength range or wavelength window. Similarly, the output port 162 is configured as an output channel, and each output channel outputs light only within a specific wavelength range or window. For example, as shown in FIG. 3, for each optical module 108, the AWG 174 has a corresponding output port operating at the same given wavelength with respect to the input port 160 of the AWG 170 operating at a given wavelength. For example, the input port 1 and the output port 1 in the optical module 108 receive and transmit signals at the same wavelength as each other, and the input port 2 and the output port 2 receive and transmit signals at the same (but different from other input ports / output ports) wavelength as each other, etc. In this regard, a pair of input port / output port includes an input port and an output port in an AWG that receive and transmit optical signals at the same wavelength respectively.

[0021] Furthermore, for example, spectrally adjacent optical signals such as spectrally adjacent optical channels or wavelengths enter different AWGs but the same corresponding ports. For example, each of the transponders 104 is connected to the same port X of each optical module 108. Therefore, the optical signals received at port X of different AWGs of the apparatus 100 occupy a given spectral window or a continuous portion of the optical spectrum based on spectrally adjacent optical signals.

[0022] The optical signals at the output port 176 of each AWG 170 are input ports 1601 to 160 MIt is a wavelength division multiplexed signal including optical signals at each wavelength received thereby. Output port 176 is coupled to optical amplifier 182 via a fiber. Optical amplifier 182 may be an optical fiber amplifier or a semiconductor amplifier. The optical fiber amplifier may be an erbium-doped fiber amplifier or a fiber Raman amplifier. According to the disclosed technology, the insertion loss of the AWG is generally lower than that of a colorless optical splitter / combiner, for example, in the case of a 1×16 splitting ratio, from 14 dB (colorless optical splitter / combiner) to less than 4 dB, so optical amplifier 182 may be a less expensive optical amplifier with a lower gain. Further, the optical amplifier is optional, and for example, depending on the reach of the system, there may be embodiments that do not require an amplifier. Other embodiments include two amplifiers, namely one in the additional direction and another in the drop direction. Further, other embodiments may include an amplifier only in the drop direction.

[0023] Optical amplifier 182 amplifies the optical signal it receives from AWG 170 and provides the amplified optical signal to, for example, WSS 112. WSS 112 consists of N multi-wavelength ports 187 and a single common port 189. For simplicity in FIG. 1, the N multi-wavelength ports 187 are shown as a single connection point. WSS 112 operates such that each wavelength from common port 189 can be switched or routed to any one of the N multi-wavelength ports, and vice versa. Essentially, WSS 112 switches wavelengths or channels across system or device 100 and functions as a programmable optical multiplexer / demultiplexer. The optical signal from common port 189 is transmitted via fiber pair 132 to a remote or far-end wavelength division demultiplexer that may be configured as described herein or may use other configurations.

[0024] For example, if the wavelength division multiplexer is configured in the demultiplexing direction according to the disclosed technique, the WSS112 sets the path of the optical signal it receives through the fiber pair 132 to the appropriate multiplexing port of the multiplexing port 187. Specifically, the WSS112 sets the path of the optical signal to the appropriate optical module 108. The AWG174 of the optical module 108 demultiplexes or separates the optical signal it receives at its input port 179 into individual wavelengths or channels and outputs those signals to the appropriate output port of the output port 162.

[0025] As a specific example, each of the transponders 104 is shown to transmit and receive optical signals via port X of AWG170, 174. Transponder 104 1.X , 104 2.X , and 104 N.X Each of these uses spectrally adjacent optical signals or channels, as shown in Figure 2 using spectrum 200. The spectrally adjacent optical signals are signals 204 from AWG1701 and AWG1741, signals 208 from AWG1702 and 1742, and AWG170 N and 174 N This is shown as signal 212. As shown in the figure, the signal is processed as a flexigrid optical signal, and signal 212 occupies a different spectral bandwidth from both signals 204 and 208. Furthermore, since the signals are spectrally adjacent to each other, they occupy a continuous portion of the optical spectrum.

[0026] In the example in Figure 2, AWG170 and 174 have a bandwidth of 4800 GHz and 16 input / output ports or input / output channels. Therefore, the spectral bandwidth is divided into 300 GHz bins, i.e., a free spectral range of 4800 GHz / 16 = 300 GHz per bin. The free spectral range (FSR) represents the distance between the center frequencies of each AWG. In this example, with a total spectrum of 4800 GHz and 16 ports, the FSR is 300 GHz. Therefore, the bandwidth per channel is 300 GHz. In other words, each input / output port pair has a channel of 300 GHz. Mapping from spectrum to ports involves a two-step process in which a larger spectral window is first selected (e.g., 300 GHz), and then the signals of the AWG ports are assigned sub-parts of the spectral window.

[0027] In the demultiplexing or drop direction, the coherent gain provided by the receiver's local oscillator is advantageously used to avoid the use of an amplifier; therefore, the disclosed technique is suitable for the use of lower-gain, less expensive optical amplifiers only in the multiplexing or addition direction. However, as stated above, other embodiments are possible when the amplifier is not used in either direction or both. Furthermore, the architecture of the device or system can limit noise leakage (in contrast, out-of-band noise from multiple optical signals is increased in architectures that use colorless multiplexers / demultiplexers instead of AWGs). In addition, filters such as tuned-to-flash (TOF) filters may be avoided on the multiplexing side in the disclosed device or system.

[0028] As shown in Figure 1, the device 100 may also be configured to include a non-contourable WSS 116 coupled between the WSS 112 and the optical module 108. The non-contourable WSS 116 includes WSS modules connected by an M×N switching fabric where M corresponds to the frequency, or by colorless, directionless and contentionless (CDC) nodes. N corresponds to the number of additional ports / drop ports directly coupled to either the transponder or premultiplexer module 108. The M×N dimensions of the WSS are not necessarily paired with the dimensions of the premultiplexer / demultiplexer module 108.

[0029] Conflict-free WSS116 provides conflict-free routing of the channels or wavelengths being used. Generally, conflict-free routing allows WSS116 to establish a first connection between a first input port and a first output port at one wavelength, without preventing a second connection from being established between a second input port and a second output port at the same wavelength. Thus, conflict-free WSS116 provides this flexibility, allowing any channel or wavelength to be routed to any port in WSS112. The output ports of WSS116 are connected to different and / or multiple WSS modules 112.

[0030] Furthermore, as shown in Figure 1, a 1×N colorless splitter / combiner 120 can be coupled to the optical module 108 and fiber pair 132 instead of WSS112, or instead of WSS112 and the non-conflicting WSS116. The 1×N colorless splitter / combiner 120 combines the N optical signals it receives from N optical modules into a single optical signal for transmission over fiber pair 132. In the demultiplexing or drop direction, the 1×N colorless splitter / combiner 120 separates the optical signal it receives over fiber pair 132 into N optical signals for N optical modules. In contrast to configurations using only WSS112, or both WSS112 and the non-conflicting WSS116, the colorless splitter / combiner configuration does not offer the routing flexibility of the other configurations and is more suitable for point-to-point type architectures.

[0031] Figure 3 shows an apparatus or system 300 according to one aspect of the disclosed technology. The apparatus or system 300 is simplified with respect to the number of input / output ports compared to Figure 1, but includes additional details regarding the connection between the optical modules 310 and the WSS 330, and channel or wavelength mapping. More specifically, the apparatus or system 300 includes four optical modules 310 coupled between the WSS 330 and a plurality of transponders 350. In the multiplexing or addition direction, each optical module 310 includes a first AWG 312 and an amplifier 314. In the demultiplexing or drop direction, each optical module 310 includes a second AWG 316. Each AWG 312, 316 has four input or output ports.

[0032] The input and output ports of each AWG are connected to their respective transponders 350, as shown for the optical module 3101. In this example, the device is configured to process 16 channels, each corresponding to a different wavelength. Specifically, the WDM grid includes the following channels at the following wavelengths: [Table 1] Spectrally adjacent channels are shown as adjacent to each other. According to the disclosed technology, spectrally adjacent signals are mapped to the same port on different AWGs, resulting in the following, as shown in Figure 3. For optical module 3101 with AWG3121 and 3141 [Table 2] For optical module 3102 with AWG3122 and 3142 [Table 3] For optical module 3103 with AWG3123 and 3143 [Table 4] For optical module 3104 with AWG3124 and 3144 [Table 5]

[0033] Referring to optical module 3101, the optical signals provided by the respective transponders CH1(λ1), CH5(λ5), CH9(λ9), and CH13(λ13) are coupled by AWG3121 to the optical signal provided to amplifier 3141. Amplifier 3141 amplifies the optical signal it receives and transmits the optical signal to WSS330. As shown in the figure, WSS330 has four ports, each communicating with optical module 3101. WSS330 processes the optical signal it receives from optical module 3101 and routes the signal to fiber 340 for transmission to another system. Channels mapped to other optical modules would be processed similarly in the multiplexing or augmentation direction.

[0034] In the demultiplexing or drop direction, the WSS330 receives the optical signal on fiber 342 and routes each channel to the appropriate optical module 310. For example, with respect to optical module 3101, this would include CH1(λ1), CH5(λ5), CH9(λ9), and CH13(λ13).

[0035] According to the disclosed technology, each channel mapped to the same corresponding port will occupy a continuous portion of the optical spectrum, as described above. Specifically, in this example, CH1, CH2, CH3, and CH4 will occupy spectral windows that occupy a continuous portion of the optical spectrum. Similarly, CH5, CH6, CH7, and CH8, CH9, CH10, CH11, and CH12, and CH13, CH14, CH15, and CH16 will also occupy spectral windows that occupy a continuous portion of the optical spectrum, respectively.

[0036] Figure 4 shows an exemplary apparatus or system 400 according to one aspect of the disclosed technology. As shown, the apparatus or system 400 includes an N optical module 410 coupled with a transponder 424 and a WSS 432, a non-conflicting WSS 436, and a WSS 438 or colorless splitter / combiner 440. Compared to Figure 1 or 3, the optical module 410 is configured differently from the optical module 108. Otherwise, the WSS 432 and 438, the non-conflicting WSS 436, and the colorless splitter / combiner 440 are configured and function similarly to their counterparts in Figure 1 or 3.

[0037] As shown in Figure 4, each optical module 410 includes a first pair of AWG411,413 in the multiplexing / addition direction and a second pair of AWG415,417 in the demultiplexing / drop direction. Each optical module 410 also includes a pair of colorless splitters / combiners 418,419. The colorless splitter / combiner 418 combines the two optical signals it receives from AWG411,413 into an optical signal supplied to amplifier 421. The colorless splitter / combiner 419 splits the signal it receives on fiber 4231 into optical signals supplied to AWG415,417.

[0038] As shown in Figure 4, the number of input / output ports of the optical unit is divided between two AWGs. Specifically, the input ports of M are divided between two AWGs, 411 and 413, and the output ports of M are divided between AWGs, 415 and 417. Each of these AWGs has fewer ports compared to the AWGs in Figure 1. Each AWG, 411 and 413, contains M / 2 ports, while each AWG, 170 and 174 in Figure 1, contains M ports.

[0039] Other embodiments are also possible. For example, the number of AWGs may include two or more per append / multiplex or drop / demultiplex path. For example, each path may contain four AWGs. To accommodate such a configuration, the splitter / combiner would need to include a 1x4 splitter combiner.

[0040] Referring to Figures 4 and 5, the apparatus or system 400 can be implemented to achieve different spectral mappings 500. In the first example 510, AWG411 and 413 are configured identically, while in the second example 520, AWG411 and 413 are shifted by FSR / 2.

[0041] During operation, the spectral profile 512 of the first example 510 reaches the additional direction as follows. First, note that by using two identical AWGs 411 and 413, each AWG needs to contain only half the number of ports compared to the configuration in Figure 1. In this regard, the spectral passbands of AWGs 411 and 413 can be configured to be twice as large. In the example shown via Figure 5, each port of AWGs 411 and 413 is configured to have the same passband as described with respect to Figures 1 and 2. For example, in the case of the first optical module 4101, port 1 of the first AWG 411 is assigned the passband or the lower half 516 of the spectrum 518. Port 1 of the second AWG 413 is assigned the upper half 520 of the spectrum 518. In an example where the transponder to port 1 of AWG411 has a bandwidth exceeding the lower half of the spectrum (516) and therefore occupies the upper half (520), the signal connected to port 1 of AWG413 would need to be configured to avoid overlapping with the signal at port 1 of AWG411.

[0042] As illustrated via spectral profile 546, the signal input to the second optical module 4102 can be processed similarly in the additional direction. Similarly, signals input to other modules can be processed similarly. Furthermore, signals input to each port of each module will be processed similarly, but will be transmitted through different spectral windows, as described above with respect to Figure 1 and as shown in Figure 2. In the drop direction, the spectrum will appear the same as in the additional direction, and the signal will be processed similarly at its respective spectral frequency, as described with respect to Figures 1 and 2.

[0043] The configuration shown in Figure 4 substantially doubles the spectral width of each AWG port while maintaining the multiplexing or demultiplexing ratio of Figure 1. This increases the flexibility of the flexigrid embodiment (e.g., a larger continuous spectral window).

[0044] In other examples 520, AWG411 and 413 are not configured to be identical. In this example, AWG411 and 413 are configured to have the same FSR, but their respective grids are shifted. As shown in the figure, this configuration allows the transponder signal to extend beyond the upper and lower limits of its assigned spectral passband.

[0045] The examples described above include configurations with two AWGs per optical module (Figure 1) and configurations with four AWGs per optical module (Figure 2). Other configurations are also possible. For example, the number of AWGs per optical module may include more than two AWGs, based on factors such as cost, flexibility, and damage loss. In this regard, more AWGs may provide greater spectral flexibility as explained in relation to Figure 5, but the cost increases with the number of AWGs. The number of AWGs may scale differently depending on whether the source and destination are within a given data center or remotely connected via a wide area network. Furthermore, the system gains provided by the disclosed technology make it attractive for applications seeking to utilize coherent pluggables in long-distance networks. Thus, the disclosed technology can find applications across a wide range of transponders.

[0046] The disclosed technology may take the form of an apparatus, system, or process having the following features and sub-features:

[0047] F1. Wavelength division multiplexing device, The system comprises multiple optical modules, each optical module having a first array waveguide grating, the first array waveguide grating including a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of transponders for transmission over a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. The plurality of optical modules are configured such that spectrally adjacent optical signals are mapped to corresponding first input ports on different optical modules among the plurality of optical modules. Each optical module has an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive the coupled signal from the first output port of the first array waveguide grating. Wavelength division multiplexer.

[0048] F2. A wavelength selector switch having multiple multi-wavelength ports and a common port, wherein the common port has a common optical signal formed from the optical signals input to the multiple multi-wavelength ports. The apparatus according to claim F1, wherein each multi-wavelength port is associated with the output of one of the optical amplifiers of the optical module, and the common port is coupled to the transmission fiber.

[0049] F3. The apparatus according to F2, comprising a non-conflicting wavelength selector switch, wherein the multiple multi-wavelength ports of the wavelength selector switch are coupled between the output of the optical amplifier of each optical module.

[0050] F4. The apparatus according to any one of F2 to F3, wherein the plurality of optical modules comprises N optical modules, and the plurality of multi-wavelength ports include N multi-wavelength ports, where N is an integer value of 2 or more.

[0051] F5. The apparatus according to any one of F2 to F4, wherein the plurality of first input ports comprises M first input ports, where M is an integer value greater than 2 and equal to N.

[0052] F6. The apparatus according to any one of F1 to F5, wherein each of the plurality of optical modules has at least two first array waveguides coupled to two or more of the plurality of first input ports.

[0053] F7. The apparatus according to any one of F1 to F6, wherein the optical data signals received at each of the multiple first input ports from each of the multiple transponders are of different wavelengths.

[0054] F8. The apparatus according to any one of F1 to F7, wherein the spectrally adjacent optical signals include an optical signal having a central wavelength within a predetermined continuous spectral bandwidth, and the central wavelength is adjacent to another central wavelength within the predetermined continuous spectral bandwidth.

[0055] F9. The apparatus according to any one of F1 to F8, wherein each of the plurality of optical modules includes a second array waveguide grid, each including a plurality of output ports configured to provide the plurality of transponders with transmission data signals received on the transmission fiber.

[0056] F10. The apparatus according to F9, wherein the second array waveguide grid includes a second input port, the second input port receiving the transmission data signal and separating the transmission data signal into individual received signals for each of the plurality of output ports.

[0057] F11. The apparatus according to F10, wherein the second input port is coupled to multiple multi-wavelength ports of a wavelength selector switch.

[0058] F12. The apparatus according to F11, wherein the plurality of output ports are equal to the plurality of first input ports of the first array waveguide grid.

[0059] F13. A colorless splitter / combiner is provided, the colorless splitter / combiner having a plurality of colorless input ports and a common port, the common port having a common optical signal formed from the optical signals input to the plurality of multi-wavelength ports, The apparatus according to F2, wherein one of each colorless input ports is associated with the output of the optical amplifier of one of the optical modules, and the common port is coupled to the transmission fiber.

[0060] F14. The apparatus according to F1, wherein the plurality of first input ports comprises M first input ports, where M is an integer value greater than 2 and not equal to N.

[0061] F15. Optical module for wavelength division multiplexer or demultiplexer, The first array waveguide grid comprises a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of optical transponders for transmission on a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. The first array waveguide grid comprises a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of optical transponders for transmission on a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. An optical module further comprising an optical amplifier having an output and an input, wherein the input of the optical amplifier is coupled to receive the coupled signal from the first output port of the first array waveguide grating.

[0062] F16. The optical module according to F15, comprising a second array waveguide grid, wherein the second array waveguide grid includes a plurality of output ports configured to provide transmission data signals received on the transmission fiber to the plurality of optical transponders.

[0063] F17. The optical module according to any one of F15 to F16, wherein the second array waveguide grid includes a second input port, the second input port receiving the transmission data signal and separating the transmission data signal into separate received signals for each of the plurality of output ports.

[0064] F18. The optical module described in any one of F15 to F17, wherein the second input port is coupled to one of the multiple wavelength ports of a wavelength selector switch.

[0065] F19. The optical module according to any one of F16 to F18, wherein the plurality of output ports are equal to the plurality of first input ports of the first array waveguide grating.

[0066] F20 system, Multiple transponders, Transmission fiber and The system comprises a plurality of optical modules, each optical module having a first array waveguide grating, the first array waveguide grating including a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of the plurality of transponders for transmission on the transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. The plurality of optical modules are configured such that spectrally adjacent optical signals are mapped to corresponding first input ports on different optical modules of the plurality of optical modules. Each optical module has an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive the coupled signal from the first output port of the first array waveguide grating. system.

[0067] A process for mapping spectrally adjacent optical signals received from a transponder (or transmitted from a corresponding first input port to a transponder) to the corresponding first input port of one of several wavelength division multiplexing / non-multiplexing optical modules implemented according to the characteristics of one of the optical modules F21.F1~F20.

[0068] While the technology described herein has been explained with reference to specific examples, it should be understood that these examples merely illustrate the principles and applications of the disclosed technology. Therefore, it should be understood that many modifications may be made to the exemplary examples and other configurations may be devised without departing from the scope of the technology as defined by the appended claims. For example, the disclosed technology, used by a reconfigurable optical additional drop multiplexer (ROADM), or more generally in a WDM network, provides colorless, non-directional, and / or non-conflicting routing of optical signals between a source and a destination.

[0069] Unless otherwise specified, the aforementioned alternatives are not mutually exclusive but can be implemented in various combinations to achieve their own advantages. Since these and other variations and combinations of the above features can be used without departing from the subject matter defined by the claims, the above description should be interpreted as illustrative rather than as an limitation of the subject matter defined by the claims. Furthermore, the provision of examples described herein, and phrases such as “such as” and “including,” should not be interpreted as limiting the subject matter of the claims to specific examples, but rather as illustrating possible variations that represent only a portion, but not all, of the disclosed technology. In addition, the same reference numerals in different drawings may identify identical or similar elements.

Claims

1. Wavelength division multiplexing device, The system comprises multiple optical modules, each optical module having a first array waveguide grating, the first array waveguide grating including a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of transponders for transmission over a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. The plurality of optical modules are configured such that spectrally adjacent optical signals are mapped to corresponding first input ports on different optical modules among the plurality of optical modules. Each optical module has an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive the coupled signal from the first output port of the first array waveguide grating. The wavelength division multiplexing device is The wavelength selector switch further comprises a common port and a plurality of multi-wavelength ports, wherein the common port has a common optical signal formed from the optical signals input to the plurality of multi-wavelength ports. A wavelength division multiplexer, in which each multi-wavelength port is associated with the output of one of the optical amplifiers of the optical module, and the common port is coupled to the transmission fiber.

2. The wavelength division multiplexer according to claim 1, comprising a non-conflicting wavelength selector switch, wherein the non-conflicting wavelength selector switch is coupled between the plurality of multiple wavelength ports of the wavelength selector switch and the output of the optical amplifier of each optical module.

3. The wavelength division multiplexer according to claim 1, wherein the plurality of optical modules comprises N optical modules, and the plurality of multi-wavelength ports include N multi-wavelength ports, where N is an integer value of 2 or more.

4. The wavelength division multiplexer according to claim 3, wherein the plurality of first input ports comprises M first input ports, where M is an integer value greater than 2 and equal to N.

5. The wavelength division multiplexer according to claim 3, wherein the plurality of first input ports comprises M first input ports, where M is an integer value greater than 2 and not equal to N.

6. The wavelength division multiplexer according to claim 1, wherein each of the plurality of optical modules has at least two first array waveguides coupled to two or more of the plurality of first input ports.

7. The wavelength division multiplexer according to claim 1, wherein the optical data signals received at each of the multiple first input ports from each of the multiple transponders are of different wavelengths.

8. The wavelength division multiplexer according to claim 1, wherein the spectrally adjacent optical signals include an optical signal having a central wavelength of one spectral range within a predetermined continuous spectral bandwidth, and the central wavelength is adjacent to the central wavelength of another spectral range within the predetermined continuous spectral bandwidth.

9. Wavelength division multiplexing apparatus according to claim 1, wherein each of the plurality of optical modules includes a second array waveguide grating, each including a plurality of output ports configured to provide the plurality of transponders with transmission data signals received on the transmission fiber.

10. The wavelength division multiplexer according to claim 9, wherein the second array waveguide grating includes a second input port, the second input port receives the transmission data signal and separates the transmission data signal into individual received signals for each of the plurality of output ports.

11. The wavelength division multiplexer according to claim 10, wherein the second input port is coupled to a plurality of multiplexed wavelength ports of a wavelength selection switch.

12. The wavelength division multiplexer according to claim 9, wherein the second array waveguide grating has the same number of output ports as the number of first input ports of the first array waveguide grating.

13. A colorless splitter / combiner is provided, the colorless splitter / combiner having a plurality of colorless input ports and one common port, the common port having a common optical signal formed from the optical signals input to the plurality of multi-wavelength ports, The wavelength division multiplexer according to claim 1, wherein one of each colorless input ports is associated with the output of one of the optical amplifiers of the optical module, and the common port is coupled to the transmission fiber.

14. An optical module for a wavelength-division multiplexer or demultiplexer, The first array waveguide grid comprises a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of a plurality of optical transponders for transmission on a transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of optical transponders. The first optical data signal received at the first input port among the plurality of first input ports on the first array waveguide grating corresponds to the second optical data signal received at the first input port on the second array waveguide grating, and the first optical data signal corresponds to the second optical data signal by being spectrally adjacent to the second optical data signal. The aforementioned optical module is An optical module further comprising an optical amplifier having an output and an input, wherein the input of the optical amplifier is coupled to receive the coupled signal from the first output port of the first array waveguide grating.

15. The optical module according to claim 14, wherein the second array waveguide grating includes a plurality of output ports configured to provide transmission data signals received on the transmission fiber to the plurality of optical transponders.

16. The optical module according to claim 15, wherein the second array waveguide grid further includes a second input port, the second input port receiving the transmission data signal and separating the transmission data signal into separate received signals for each of the plurality of output ports.

17. The optical module according to claim 16, wherein the second input port is coupled to a plurality of multi-wavelength ports of a wavelength selector switch.

18. The optical module according to claim 15, wherein the second array waveguide grating has the same number of output ports as the number of first input ports of the first array waveguide grating.

19. It is a system, Multiple transponders, Transmission fiber and The system comprises a plurality of optical modules, each optical module having a first array waveguide grating, the first array waveguide grating including a first output port and a plurality of first input ports, each of the plurality of first input ports configured to receive an optical data signal from one of the plurality of transponders for transmission on the transmission fiber, and the first output port outputs a coupled signal formed from the optical data signals received from the plurality of transponders. The plurality of optical modules are configured such that spectrally adjacent optical signals are mapped to corresponding first input ports on different optical modules of the plurality of optical modules. Each optical module has an optical amplifier having an output and an input, the input of the optical amplifier being coupled to receive the coupled signal from the first output port of the first array waveguide grating. The aforementioned system, A wavelength selector switch having a common port and a plurality of multi-wavelength ports, wherein the common port has a common optical signal formed from the optical signals input to the plurality of multi-wavelength ports, A system in which each multi-wavelength port is associated with the output of one of the optical amplifiers of the optical module, and the common port is coupled to the transmission fiber.

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