Optical coupling device

Abstract

The optical coupling device (200) comprises a plurality of input channels (201, 202, 203, 204); a plurality of output channels (291, 292, 293, 294); and a plurality of coupling channels. Each coupling channel is configured to couple an input channel to an output channel. The plurality of coupling channels includes an amplitude modulator configured to adjust an amplitude of the optical signal.

Description

Technical Field

[0001] The present disclosure relates to an optical coupling device, and in particular to a configurable optical coupling device. background

[0002] Optical matrix structures including matrix multiplication units have been reported for realizing photonic computing, see, for example, Feldmann, J., Youngblood, N., Karpov, M. et al., Parallel convolutional processing using an integrated photonic tensor core, Nature 589, 52–58 (2021). https: / / doi.org / 10.1038 / s41586-020-03070-1 .

[0003] Conventional optical coupling devices, such as optical switches, are based on electro-optical conversion. In this approach, an optical input signal is converted to an electrical signal, rerouted, and converted back to an optical signal at the output. Such switching devices are typically slow and can be described as having high latency. Alternative approaches based on fiber optic architectures and / or using micro-electromechanical system (MEMS) modulators have been proposed. However, such systems are still limited by relatively high latency, inefficiencies due to optical losses, and a lack of flexibility. For example, these systems may not be designed to perform signal replication.

[0004] It is an object of the present disclosure to address one or more of the above limitations. Overview

[0005] According to a first aspect of the present disclosure, an optical coupling device is provided, comprising: a plurality of input channels; a plurality of output channels; and a plurality of coupling channels, each coupling channel being configured to couple an input channel to an output channel, wherein the plurality of coupling channels include an amplitude adjuster configured to adjust the amplitude of an optical signal.

[0006] For example, the amplitude modulator may be configured to attenuate and / or amplify the optical signal. The amplitude modulator may be an optical modulator or an optical amplifier or a combination of both. The channel may be implemented as a waveguide, such as an integrated waveguide.

[0007] Optionally, the plurality of coupling channels form at least one main group of coupling channels configured to couple the plurality of input channels to a single output channel.

[0008] Optionally, the plurality of coupling channels form at least one subgroup of coupling channels configured to couple a single input channel to a plurality of output channels.

[0009] Optionally, each coupling channel extends between a first coupler coupled to the input channel and a second coupler coupled to the output channel.

[0010] For example, the coupler may be a directional coupler, or a multimode interference beam splitter (MMIS) or a Y-beam splitter.

[0011] Optionally, the first coupler is designed to split an optical signal propagating through the input channel at a first ratio, such that a portion of the signal is directed to the coupling channel and a remaining portion is transmitted through the input channel.

[0012] Optionally, the second coupler is designed to combine the optical signal propagating through the coupling channel with another signal propagating through the output channel at a second ratio.

[0013] Optionally, the first ratio of the first couplers in the subgroup is selected to evenly distribute optical signals received at the input channels among the coupled channels in the subgroup.

[0014] Optionally, the second ratio of the second couplers in the main group is selected so that each input channel contributes equally to the output signal received at the output port of the single output channel associated with the main group.

[0015] Optionally, the amplitude adjuster includes at least one of an optical attenuator and an optical amplifier.

[0016] For example, each coupling channel of the primary group and / or the secondary group includes at least one of an optical attenuator and an optical amplifier.

[0017] Optionally, one or more of the output channels comprises an optical amplifier.

[0018] Optionally, the optical coupling device comprises a controller configured to control the operation of a plurality of optical attenuators or optical amplifiers or a combination of both optical amplifiers and optical attenuators.

[0019] For example, the controller may be configured to control the amplification factor of an optical amplifier or the attenuation factor of an optical attenuator.

[0020] Optionally, the controller is configured to control the plurality of amplitude modulators to perform optical signal replication or optical computation.

[0021] For example, the controller may be configured to perform multiply-accumulate (MAC) operations.

[0022] Optionally, the controller is configured to switch on the optical amplifiers of the subgroup such that an input optical signal received at the input channel of the subgroup generates a plurality of replicated optical signals provided at the output channels.

[0023] Optionally, each input channel extends along a corresponding longitudinal axis, and wherein the input channels are arranged substantially parallel to each other.

[0024] Optionally, the coupling channel has linear portions, wherein the linear portions of the coupling channel are arranged substantially parallel to each other.

[0025] Optionally, the linear portion of the coupling channel is substantially perpendicular to the input channel.

[0026] Optionally, the input channel is formed in a first layer arranged in a first plane, and the coupling channel is formed in a second layer arranged in a second plane.

[0027] For example, the first plane can be substantially parallel to the second plane. The second layer can be disposed above or below the first layer. The first layer and the second layer can be made of the same material or different materials.

[0028] According to a second aspect of the present disclosure, there is provided an integrated optical chip comprising the optical coupling device according to the first aspect.

[0029] According to a third aspect of the present disclosure, there is provided a method for manipulating an optical signal, the method comprising: An optical coupling device is provided, the optical coupling device comprising: a plurality of input channels; a plurality of output channels; and a plurality of coupling channels, each coupling channel being configured to couple an input channel to an output channel, wherein the plurality of coupling channels comprises an amplitude adjuster configured to adjust the amplitude of an optical signal; sending the optical signal through an input channel; and The amplitude modulator is operated to manipulate the optical signal.

[0030] For example, the amplitude modulator may be operated to perform signal replication or to perform a computational task (eg, by combining several input signals).

[0031] Optionally, the method includes: splitting the optical signal into a plurality of intermediate signals using a coupling channel; and amplifying the intermediate signal using an amplitude adjuster to obtain a plurality of replica signals at the output channel.

[0032] Optionally, the method comprises combining several input signals to perform a computation operation. For example, the computation operation may be a multiply-accumulate (MAC) operation.

[0033] The options described in relation to the first aspect of the disclosure are also common to the second and third aspects of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present disclosure is described in more detail below by way of example and with reference to the accompanying drawings, in which: Figure 1is a schematic diagram of an optical coupling device; Figure 2 yes Figure 1 Figure 1 is a diagram of an exemplary embodiment of an optical coupling device; Figure 3 yes Figure 1 FIG. 1 is a diagram of another exemplary embodiment of an optical coupling device; Figure 4 yes Figure 3 FIGURE 1 shows a modified version of an optical coupling device; Figure 5 is a flow chart of a method for manipulating an optical signal. describe

[0035] Figure 1 FIG2 is a schematic diagram of an optical coupling device. An optical coupling device 100 (also known as an optical switch) can be used to connect M optical input ports to N optical output ports in a configurable manner. The coupling device has M input channels and N output channels.

[0036] A plurality of coupling channels (not shown) are also provided. Each coupling channel is configured to couple an input channel to an output channel. Each coupling channel is provided with a dedicated amplitude modulator configured to attenuate or amplify the optical signal. The amplitude modulator may be an optical modulator or an optical amplifier, or a combination of both. A controller, such as an electronic controller or an optical controller, is provided to control the operation of the amplitude modulator.

[0037] The input ports are designed to receive optical input signals labeled Sin_1-Sin_M. The optical input signals can be generated by one or more light sources and coupled to the input ports. Depending on the type of light source selected, optical coupling can be achieved using optical fibers (e.g., via grating couplers or edge coupling). Similarly, the output ports are configured to provide optical output signals Sout_1 through Sout_N. The optical coupling device 100 can be used to manipulate optical signals in various ways. For example, the amplitude modulator can be operated to replicate or duplicate one or more optical signals. The amplitude modulator can also be operated to perform computational tasks. For example, the controller can be configured to perform addition and / or multiplication of the optical signals.

[0038] The optical input signal contains the information or data to be transmitted. A light source, such as a laser, can be used to generate the optical signal, which is then modulated with the data to be transmitted. Device 100 is designed to route the input optical signal independently of the information or data present in the input optical signal. Instead, the device / controller is preconfigured to route the signal in a predetermined manner based on the application. This type of device may be referred to as a Layer 1 (L1) switch.

[0039] Figure 2 yes Figure 1 1. The optical coupling device 200 has four input ports coupled to four input channels 201-204 and four output ports coupled to four output channels 291-294.

[0040] Coupling between the input channels and the output channels is provided by four groups of coupling channels (referred to as main groups) labeled 210, 220, 230, 240. In each main group, the coupling channels are configured to couple multiple input channels to a single output channel.

[0041] The first group 210 has four coupling channels 211, 212, 213, and 214 configured to couple the input channels 201, 202, 203, and 204 to the first output channel 291. The coupling channel 211 is provided between the first input channel 201 and the first output channel 291; the coupling channel 212 is provided between the second input channel 202 and the first output channel 291; the coupling channel 213 is provided between the third input channel 203 and the first output channel 291; and the coupling channel 214 is provided between the fourth input channel 204 and the first output channel 291.

[0042] Similarly, the second group 220 has four coupling channels 221, 222, 223, and 224 configured to couple the input channels 201, 202, 203, and 204 to the second output channel 292. The third group 230 has four coupling channels 231, 232, 233, and 234 configured to couple the input channels 201, 202, 203, and 204 to the third output channel 293. The fourth group 240 has four coupling channels 241, 242, 243, and 244 configured to couple the input channels 201, 202, 203, and 204 to the fourth output channel 294.

[0043] Device 200 is also provided with four subgroups. Within each subgroup, coupling channels are configured to couple a single input channel to multiple output channels. Coupling channels 211, 221, 231, and 241 form a first subgroup. Channels 212, 222, 232, and 242 form a second subgroup. Channels 213, 223, 233, and 243 form a third subgroup. Channels 214, 224, 234, and 244 form a fourth subgroup.

[0044] In this manner, each input channel can be coupled to multiple outputs. For example, the first channel 201 is coupled to the first output channel 291 via coupling channel 211, to the second output channel 292 via coupling channel 221, to the third output channel 293 via coupling channel 231, and to the fourth output channel 294 via coupling channel 241.

[0045] It will be appreciated that the above arrangement can be extended to M input channels and N output channels, where M and N are integers. Thus, more generally, each input channel is provided with N coupling channels for coupling to N output channels.

[0046] Each coupling channel extends between a first coupler (also referred to as an input coupler) coupled to an input channel and a second coupler (also referred to as an output coupler) coupled to a corresponding output channel. For example, coupling channel 211 extends between input coupler C1a at input channel 201 and output coupler Cout1a at output channel 291. Similarly, coupling channel 214 extends between input coupler C1d at input channel 204 and output coupler Cout1d at output channel 291.

[0047] Couplers can be implemented as directional couplers, multimode interference beam splitters (MMIS), or Y-beam splitters. An input coupler is designed to split an input optical signal propagating through an input channel, so that a portion of this signal (also called an intermediate signal) is directed to the coupling channel, while the remaining portion continues to propagate through the input channel. Similarly, an output coupler is designed to combine an optical signal propagating through the coupling channel with another optical signal transmitted through the output channel.

[0048] The splitting ratios of the input couplers of the subgroup can be selected so that each coupled channel provided along the input channel receives the same amount or amplitude of optical signal, so that the input signal is evenly distributed among the N coupled channels of the subgroup. For the subgroup formed by 211, 221, 231, and 241, and assuming no losses, this would mean that coupler C1a couples ¼ of the input optical signal to channel 211, coupler C2a couples ⅓ of the remaining optical signal to channel 221, coupler C3a couples ½ of the remaining optical signal to channel 231, and coupler C4a couples all (1 / 1) of the remaining optical signal to channel 241. In this manner, each of coupled channels 211, 221, 231, and 241 receives a quarter of the total input optical signal received at the input port.

[0049] The splitting ratios of the output couplers of the main group can be selected so that the M inputs contribute equally to the output signal provided at the output port of the main group. For the main group 210, the splitting ratios of the output couplers Cout1a, Cout1b, Cout1c, and Cout1d coupled to the first output channel 291 can be 1 / 4, 1 / 3, 1 / 2, and 1 / 1, respectively.

[0050] In this example, the output signal received at the output port consists of ¾ of the signal from coupled channels 212, 213, and 214 and ¼ of the signal from coupled channel 211. The signal received by output channel 291 at the output of 212 consists of 2 / 3 of the signal from coupled channels 213 and 214 and ¾ of the signal from coupled channel 212. The signal received by output channel 291 at the output of 213 consists of ½ of the signal from coupled channel 214 and ½ of the signal from coupled channel 213. The signal received by output channel 291 at the output of 214 is 100% (1 / 1) of the signal from coupled channel 214.

[0051] Depending on the device implementation, further adjustments may be needed to account for optical losses at the intersection between the input channel and the coupled channel, as well as optical losses associated with the coupler.In general, the ratio can be adjusted so that each input contributes the same amount of optical signal to each output.

[0052] Each coupling channel includes an optical attenuator or an optical amplifier or a combination of both. A controller (not shown) is provided to control the operation of the optical attenuators and / or optical amplifiers as dictated by the chosen design.

[0053] exist Figure 2 In the example, each coupling channel is provided with an optical modulator for modulating the optical signal transmitted through the coupling channel. For example, coupling channels 211, 212, 213, and 214 are provided with modulators M1, M2, M3, and M4, respectively. In this configuration, the modulators can be densely packed, thereby reducing the device's footprint.

[0054] Modulators are used to control the degree of transmission of a signal passing through a coupling channel. This allows the configuration of the coupling device to be varied. The modulator is configured to attenuate the optical signal with an adjustable attenuation coefficient. When the attenuation coefficient is maximum, the optical signal is extinguished and cannot propagate. Similarly, if the attenuation coefficient is minimum (e.g., zero), the entire optical signal can propagate.

[0055] The output coupler is used to combine the modulated signal transmitted through the coupling channel with other modulated signals transmitted through other coupling channels.

[0056] exist Figure 2 In an example, the input channels are linear channels arranged substantially parallel to one another. The coupling channel has a linear portion disposed between two curved portions of the input coupler and the output coupler. The linear portions of the coupling channel are substantially parallel to one another and perpendicular to the input channels.

[0057] Depending on the design, the input channel and the coupling channel can cross at several intersection points. Alternatively, the input channel and the coupling channel can be arranged in different planes so that they do not cross.

[0058] Optical coupling device 200 can function as an optical switch, connecting M optical input ports to N optical output ports in a reconfigurable manner with ultra-low latency. Device 200 also enables duplication of an input signal from one to multiple connections. The selection of which input is connected to which output can be freely reconfigured at high speed (e.g., at GHz frequencies) by controlling attenuators and / or amplifiers. The device avoids electro-optical conversion of the input signal, thus achieving ultra-low latency (only the time-of-flight of the optical signal, e.g., less than 1 ns). Another advantage is the ability to duplicate signals. In other words, an input optical signal at one input port can be sent to multiple output ports. This can be achieved while compensating for optical losses, ensuring that the intensity of the duplicated output optical signal is sufficient for detection or further processing.

[0059] Figure 3 yes Figure 1 FIG. 300 is another exemplary embodiment of an optical coupling device having a Figure 2 200, and the same reference numerals are used to designate corresponding components. In this embodiment, each coupling channel is equipped with an optical amplifier and an optical attenuator. For example, coupling channel 211 is equipped with optical amplifier 361a and optical attenuator 371a. Similarly, coupling channel 214 is equipped with optical amplifier 361d and optical attenuator 371d.

[0060] The optical amplifier may be implemented as a semiconductor optical amplifier (SOA). The optical attenuator may be a Mach-Zehnder modulator (MZM), also known as a Mach-Zehnder interferometer (MZI), an electro-absorption modulator (EAM), a microring resonator, or a phase change material (PCM) modulator.

[0061] An attenuator can be used to cancel or eliminate optical signals that should not be transmitted to the output port. In this scenario, the amplifier is off and the attenuator is on. Amplifier / attenuator combinations can be implemented using the same component or as two separate components. A modulator component (such as an SOA) can be designed to amplify the signal when a positive voltage is applied and to attenuate the signal when a negative voltage is applied.

[0062] In operation, an optical input signal propagates through an input channel (e.g., input channel 201), and input couplers C1a-C4a direct a portion of the optical input signal to coupling channels 211, 221, 231, and 241, respectively. When an optical amplifier located on one of these coupling channels is switched on, the optical signal propagating through that channel is amplified. This can be used to recover optical losses in the optical path. By switching on multiple optical amplifiers connected to the same input port, multiple output ports can be addressed to perform signal replication.

[0063] As referenced above Figure 2 As explained, the splitting ratios of input couplers C1a, C2a, C3a, and C4a can be selected so that each coupled channel receives ¼ of the input optical signal. If optical amplifiers 361a, 362a, 363a, and 364a are all turned on, each of coupled channels 211, 221, 231, and 241 can provide the same amplified optical signal at output channels 291, 292, 293, and 294. Assuming the same optical loss in each coupled channel, this can be achieved by using the same amplification factor for each of amplifiers 361a-364a. Alternatively, different amplification factors can be used to compensate for different optical losses.

[0064] Optical attenuators can be used to prevent optical signals propagating through coupling channels from being transmitted to output channels. For example, optical attenuators 371a, 372a, 373a, and 374a can be disabled, while all other remaining attenuators are enabled to block the propagation of input signals originating from input channels 202, 203, and 204, thereby affecting the output signals at output ports 1-4. In this example, the input optical signal received at input channel 201 will be replicated four times at output ports 1 through 4.

[0065] The replicated output signal has the same waveform profile as the input signal, but can have a different amplitude. As described above, the amplifier configuration allows for compensating for optical losses and even amplifying the signal to levels higher than the input signal. The level of amplification can be selected based on the sensitivity of the optical detector used to sense the output signal.

[0066] It should also be understood that Figure 3 The circuit can be implemented using only optical attenuators without optical amplifiers, although in this case the input signal amplitude will be reduced by >1 / (N*M).

[0067] Figure 4 yes Figure 3FIG1 shows a modified version of an optical coupling device. In this example, output channels 291, 292, 293 and 294 are provided with additional optical amplifiers 481, 482, 483 and 484, respectively. This implementation provides further flexibility for amplifying the output signal provided at each of the output channels.

[0068] As reference Figures 1 to 4 The optical coupling device may be implemented using an integrated optical circuit such as a photonic integrated circuit (PIC).

[0069] The input channel, coupling channel, and output channel can be implemented in a single layer. In this case, the input channel and coupling channel may intersect at several intersections. This can result in some signal loss and optical crosstalk. For example, the optical signal may be scattered into another (perpendicular) channel at the intersection. Alternatively, the input channel can be formed in a first layer, while the coupling channel and output channel are formed in a second layer. The first layer can be arranged in a first plane, and the second layer can be arranged in a second plane substantially parallel to the first plane. For example, the second layer can be arranged above or below the first layer. In this way, channel intersection can be avoided, thereby reducing optical loss.

[0070] The various channels can be implemented as waveguides, such as integrated waveguides. The waveguides can be made of the same or different materials. In a specific example, the input waveguide can be implemented in a silicon nitride layer, while the coupling waveguide can be implemented in a silicon layer. The silicon layer can be disposed beneath the silicon nitride layer. This approach allows for the construction of compact devices with fast signal propagation times between input and output ports for optical signals. For example, compact photonic integrated circuits less than 2 × 2 cm² can be realized, thereby reducing flight time to achieve ultra-low latency and recovering from signal losses via optical amplifiers.

[0071] Since no electrical-to-optical conversion of the signal is involved, latency is defined by the time it takes the optical signal to traverse the circuit (and attached optical fiber, if any). By using only broadband components (such as directional couplers and broadband SOAs), no additional tuning is required to compensate for wavelength variations. Optical coupling devices can be designed to operate at different wavelengths depending on the application. For example, an optical coupling device can be designed to operate across the primary telecommunications window of wavelengths of approximately 1200nm-1600nm. Knowledge of the input wavelength of the optical input signal is not required (beyond the general optical region of the spectrum).

[0072] The modulator may be an electro-optic modulator, such as an EOM based on indium phosphide (InP), silicon germanium, or lithium niobate. Other types of integrated modulators are also contemplated, including polymer-based modulators and optically controlled modulators, such as phase change material modulators (PCMs), among others.

[0073] The optical coupling device of the present disclosure can be used in different applications.As described above, the optical coupling device can be used to replicate an input optical signal multiple times and distribute the replicated signals at multiple outputs.

[0074] Optical coupling devices can also be used as computing devices for performing computational tasks, such as matrix multiplication. Modulating optical signals can be used to perform multiplication operations on optical signals by predetermined coefficients. Accumulating modulated signals can be used to perform multiply-accumulate (MAC) operations. Accumulation is performed by adding signals over time. For example, an amplitude modulator can be used to accumulate multiple optical signals. By connecting multiple optical coupling devices, the size of the matrix can be increased.

[0075] For example, a first input signal having an amplitude a may be provided at input channel 201, and a second input signal having an amplitude b may be provided at input channel 202. Figure 2 The modulators M1 and M2 are set to attenuation values ​​corresponding to the factors c and d, performing a multiplication between the input signal and the amplitude adjustment coefficients: (a*c) for the intermediate signal propagated through the coupling channel 211, and (b*d) for the intermediate signal propagated through the coupling channel 212. By combining the intermediate signals in the output channel 291 in equal ratios, the output amplitude represents the operation a*c + b*d (MAC operation). It should be understood that Figure 3 and Figure 4 Devices can also be used to perform such operations, for example using amplification factors or attenuation factors.

[0076] Figure 5 1 is a flow chart of a method for manipulating an optical signal. At step 510, an optical coupling device is provided. The optical coupling device includes a plurality of input channels; a plurality of output channels; and a plurality of coupling channels, each configured to couple an input channel to an output channel. The plurality of coupling channels includes an amplitude adjuster configured to adjust the amplitude of the optical signal. At step 520, the optical signal is transmitted through the input channels. At step 530, the amplitude adjuster is operated to manipulate the optical signal.

[0077] For example, the amplitude modulator can be operated to replicate the optical signal. This can be achieved by using a coupling channel to split the optical signal into multiple intermediate signals to obtain multiple replicated signals at the output channel. The amplitude modulator can also be used to amplify the intermediate signals.

[0078] It will be appreciated by those skilled in the art that variations of the disclosed arrangements are possible without departing from the present disclosure. Therefore, the above description of specific embodiments is made by way of example only and not for limiting purposes. It will be clear to those skilled in the art that minor modifications may be made without significantly changing the described operation.

Claims

1. An optical coupling device, comprising: Multiple input channels; Multiple output channels; and A plurality of coupling channels, each coupling channel configured to couple the input channel to the output channel, wherein the plurality of coupling channels includes an amplitude adjuster configured to adjust the amplitude of the optical signal.

2. The optical coupling device according to claim 1, wherein The plurality of coupling channels form at least one main set of coupling channels configured to couple the plurality of input channels to a single output channel.

3. The optical coupling device according to claim 1 or 2, wherein: The plurality of coupling channels form at least one subgroup of coupling channels configured to couple a single input channel to a plurality of output channels.

4. The optical coupling device according to claim 2 or 3, wherein: Each coupling channel extends between a first coupler coupled to the input channel and a second coupler coupled to the output channel.

5. The optical coupling device according to claim 4, wherein: The first coupler is designed to split an optical signal propagating through the input channel at a first ratio, such that a portion of the signal is directed to the coupling channel and a remaining portion is transmitted through the input channel.

6. The optical coupling device according to claim 4 or 5, wherein: The second coupler is designed to combine an optical signal propagating through the coupling channel with another signal propagating through the output channel at a second ratio.

7. The optical coupling device according to claim 5, wherein: The first ratio of the first couplers in the subgroup is selected to evenly distribute optical signals received at the input channels among the coupled channels in the subgroup.

8. The optical coupling device according to claim 6, wherein: The second ratio of the second couplers in the main group is selected such that each input channel contributes equally to an output signal received at an output port of the single output channel associated with the main group.

9. An optical coupling device according to any one of the preceding claims, wherein The amplitude adjuster includes at least one of an optical attenuator and an optical amplifier.

10. An optical coupling device according to any one of the preceding claims, wherein One or more output channels include an optical amplifier.

11. An optical coupling device according to any preceding claim, comprising a controller configured to control the operation of a plurality of optical attenuators or optical amplifiers or a combination of both optical amplifiers and optical attenuators.

12. The optical coupling device according to claim 11, wherein The controller is configured to control the plurality of amplitude modulators to perform optical signal replication or optical computation.

13. The optical coupling device according to claim 12, wherein: The controller is configured to switch on the optical amplifiers of the subgroup such that an input optical signal received at the input channels of the subgroup generates a plurality of replicated optical signals provided at the output channels.

14. An optical coupling device according to any one of the preceding claims, wherein Each input channel extends along a corresponding longitudinal axis, and wherein the input channels are arranged substantially parallel to each other.

15. The optical coupling device according to claim 14, wherein: The coupling channel has a linear portion, wherein the linear portions of the coupling channel are arranged substantially parallel to each other.

16. The optical coupling device according to claim 15, wherein The linear portion of the coupling channel is substantially perpendicular to the input channel.

17. An optical coupling device according to any one of the preceding claims, wherein The input channel is formed in a first layer disposed in a first plane, and wherein the coupling channel is formed in a second layer disposed in a second plane.

18. An integrated optical chip comprising the optical coupling device according to any one of the preceding claims.

19. A method of manipulating an optical signal, the method comprising: An optical coupling device is provided, the optical coupling device comprising: a plurality of input channels; a plurality of output channels; and a plurality of coupling channels, each coupling channel being configured to couple an input channel to an output channel, wherein the plurality of coupling channels comprises an amplitude adjuster configured to adjust the amplitude of an optical signal; sending the optical signal through an input channel; and The amplitude modulator is operated to manipulate the optical signal.

20. The method according to claim 19, comprising: using the coupling channel to split the optical signal into a plurality of intermediate signals; and The intermediate signal is amplified using the amplitude adjuster to obtain a plurality of replica signals at the output channels.

21. The method according to claim 19, comprising: Combines several input signals to perform a computational operation.

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