CN117118509A - Optical channel monitor and monitoring method - Google Patents

Abstract

The invention discloses an optical channel monitor and a monitoring method, which relate to the technical field of optical channel monitoring, wherein the optical channel monitor comprises a photoelectric detector, a signal processor and a spectrum modulation chip; the spectrum modulation chip comprises an optical input port, an optical output port group and a spectrum disturbance structure, wherein the optical output port group comprises at least one optical output port, and the spectrum disturbance structure is used for receiving an input optical signal input through the optical input port, carrying out disturbance processing on the input optical signal to obtain a plurality of output optical signals with different optical characteristics and outputting the plurality of output optical signals through the optical output port group; the photoelectric detector is used for converting the optical power of the output optical signal into a corresponding electric signal; the signal processor is used for acquiring related data of spectrums of the input optical signals according to a plurality of the output optical signals. Compared with the traditional mode, the method has the advantages of high speed, high resolution, low cost, small volume and the like.

Description

Optical channel monitor and monitoring method

Technical Field

The invention relates to the technical field of optical channel monitoring, in particular to an optical channel monitor and a monitoring method.

Background

The wavelength division multiplexing (WDM, wavelength Division Multiplexing) is a technology for converging optical signals with different wavelengths through a combiner and coupling the optical signals into the same optical fiber to perform data transmission, and the technology can improve the transmission capacity of the optical fiber and improve the utilization efficiency of optical fiber resources. At the beginning of the development of the technology, the wavelength interval is controlled to be tens of nm due to limited technical conditions. This comparatively dispersive wavelength division multiplexing is called sparse wavelength division multiplexing, i.e. CWDM (Coarse WDM). Later, as technology becomes more advanced, wavelength intervals are pressed shorter and shorter to the order of a few nm, so that tight WDM, called dense wavelength division multiplexing, is DWDM (Dense WDM), is formed.

The channel interval in the communication network adopting the DWDM technology is smaller and smaller, the channel interval is gradually reduced from 200GHz to 100GHz, 50GHz and even 25GHz, the number of channels is more and more, and the rate is continuously improved, so that the wavelength, the power and the signal-to-noise ratio of each optical channel signal must be monitored at key nodes in order to ensure the stable and efficient operation of the communication network.

Common optical channel monitors are largely classified into spectroscopic and tunable filter types. Among them, tunable filter-based optical channel monitors are largely classified into michelson interferometers, fabry-perot interferometers, dielectric film filters, and the like. The basic structure and working principle of the tunable filter type optical channel monitor are as follows: the optical signal enters the filter, the filter outputs a signal with a certain wavelength range only after filtering, the signal is received by the detector, and the passing wavelength of the filter is changed continuously after tuning, and finally the whole bandwidth range is covered. The optical channel monitor has small volume, no inter-channel interference caused by light splitting, and only needs a single detector, but the existing filter has insufficient resolution, slow modulation rate and slow spectrum scanning rate, cannot realize real-time monitoring of signals, and has high cost due to immaturity.

Disclosure of Invention

The present invention aims to solve one of the technical problems in the related art to a certain extent. Therefore, the invention provides an optical channel monitor and a monitoring method, which utilize the principle of calculating a reconstruction spectrometer to monitor an optical channel, can be integrated on a spectrum modulation chip, can monitor an optical signal in a wide spectrum while reducing the volume and the cost, and has high speed and high resolution.

In order to achieve the above object, the present invention adopts the following technical scheme in a first aspect:

an optical channel monitor comprises a photoelectric detector, a signal processor and a spectrum modulation chip; the spectrum modulation chip comprises an optical input port, an optical output port group and a spectrum disturbance structure, wherein the optical output port group comprises at least one optical output port, and the spectrum disturbance structure is used for receiving an input optical signal input through the optical input port, carrying out disturbance processing on the input optical signal to obtain a plurality of output optical signals with different optical characteristics and outputting the plurality of output optical signals through the optical output port group; the photoelectric detector is used for converting the optical power of the output optical signal into a corresponding electric signal; the signal processor is used for acquiring related data of spectrums of the input optical signals according to a plurality of the output optical signals.

Optionally, the spectrum perturbation structure comprises a plurality of cascaded active tunable spectrum perturbation units, and the signal processor is further used for generating a control signal; said set of light output ports comprising one of said light output ports; the active tunable spectrum disturbance units are connected in series, different disturbances are generated in time sequence according to the tuning of the control signals, and therefore the optical output ports output a plurality of different output optical signals at different moments.

Optionally, the spectrum perturbation structure includes a plurality of optical path components, the plurality of optical path components are connected with the optical input port through an optical splitter, each optical path component includes a plurality of cascaded passive spectrum perturbation units, and the plurality of passive spectrum perturbation units in different optical path components have different spectrum responses so that the plurality of optical path components generate different perturbations on the input optical signal; the optical output port group comprises a plurality of optical output ports, and the optical output ports are in one-to-one correspondence with the optical path components and output a plurality of different output optical signals; the power distribution of different ones of said output optical signals in the frequency domain is different.

Optionally, the spectrum disturbance structure includes a plurality of optical path components, and a plurality of the optical path components are connected with the optical input port through an optical splitter; the optical path components comprise a plurality of cascaded spectrum disturbance units, the plurality of spectrum disturbance units in different optical path components have different spectrum responses so that the plurality of optical path components generate different disturbances on the input optical signal, and the plurality of cascaded spectrum disturbance units of at least one optical path component are a plurality of cascaded active tunable spectrum disturbance units; the signal processor is also used for providing a control signal for tuning of the active tunable spectrum disturbance unit; the optical output port group comprises a plurality of optical output ports, and the optical output ports are in one-to-one correspondence with the optical path components so as to output different output optical signals.

Optionally, at least one active tunable spectrum disturbance unit in the spectrum disturbance structure is an active asymmetric mach-zehnder interferometer, the active asymmetric mach-zehnder interferometer is provided with two tuning arms with unequal lengths and a phase modulator arranged on at least one of the tuning arms, and the phase modulator tunes the phase of an optical signal entering the tuning arm according to the control signal so as to adjust the power distribution of the output optical signal in a frequency domain.

Optionally, an arm length difference exists between two tuning arms of the active asymmetric mach-zehnder interferometer; the plurality of active asymmetric mach-zehnder interferometers each have a different arm length difference.

Optionally, at least one active tunable spectrum disturbance unit in the spectrum disturbance structure is a micro-loop filter with a resonance structure, a phase modulator is arranged in the resonance structure of the micro-loop filter, and the phase modulator tunes the phase of an optical signal entering the resonance structure according to the control signal so as to adjust the power distribution of the output optical signal in a frequency domain.

Alternatively, the micro-rings of the plurality of micro-ring filters have different circumferences, respectively.

Optionally, at least one of the passive spectrum disturbance unit or the spectrum disturbance unit in the spectrum disturbance structure is a passive asymmetric Mach-Zehnder interferometer or a micro-ring filter with a resonance structure.

In addition, the invention also provides an optical channel monitoring method in a second aspect, which comprises the following steps: acquiring a plurality of different output optical signals corresponding to the input optical signals; performing spectral calculation reconstruction on the input optical signal according to a plurality of different output optical signals; a spectrum of the input optical signal is obtained.

Optionally, before the step of obtaining a plurality of different output optical signals corresponding to the input optical signals, sending a control signal to the spectrum modulation chip; wherein the number of the plurality of different output light signals is related to the control signal.

These features and advantages of the present invention will be disclosed in more detail in the following detailed description and the accompanying drawings. The best mode or means of the present invention will be described in detail with reference to the accompanying drawings, but is not limited to the technical scheme of the present invention. In addition, these features, elements, and components are shown in plural in each of the following and drawings, and are labeled with different symbols or numerals for convenience of description, but each denote a component of the same or similar construction or function.

Drawings

The invention is further described below with reference to the accompanying drawings:

fig. 1 is a schematic block diagram of an optical channel monitor according to the present embodiment.

Fig. 2 is a block diagram of the spectrum modulation chip in this embodiment.

Fig. 3 is a schematic structural diagram of the spectrum modulation chip in this embodiment, which shows a time domain tunable spectrum disturbance structure.

Fig. 4 is a schematic structural diagram of the time-domain tunable spectrum disturbance structure in this embodiment, which shows an active asymmetric mach-zehnder interferometer therein.

Fig. 5 is a schematic structural diagram of the time-domain tunable spectrum disturbance structure in this embodiment, which shows a micro-ring filter with a resonant structure.

Fig. 6 is a schematic structural diagram of the time-domain tunable spectrum disturbance structure in this embodiment, which shows an active asymmetric mach-zehnder interferometer and a micro-ring filter with a resonant structure.

Fig. 7 is a schematic structural diagram of the spectrum modulation chip in this embodiment, which shows a spatial spectrum disturbance structure therein.

Fig. 8 is a flowchart of the optical channel monitoring method in this embodiment.

Fig. 9 is a graph of the spectrum reconstruction result of the optical signal at the C-band 50GHz channel interval by using the optical channel monitoring method in this embodiment.

Wherein, 1, an asymmetric Mach-Zehnder interferometer; 12. a tuning arm; 2. a micro-loop filter; 21. a resonant structure; 3. a phase modulator.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The examples in the embodiments are intended to illustrate the present invention and are not to be construed as limiting the present invention.

Reference in the specification to "one embodiment" or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment itself can be included in at least one embodiment of the present patent disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

Examples:

as shown in fig. 1, an optical channel monitor is shown for monitoring an optical signal within an optical channel in an optical transmission network system. The optical transmission network may be a Dense Wavelength Division Multiplexing (DWDM) optical transmission network, or may be a sparse wavelength division multiplexing (CWDM) optical transmission network, which is not limited. The optical channel monitor comprises an optical waveguide, a spectrum modulation chip, a photoelectric detector and a signal processor.

The optical channel of the optical transmission network system is used for transmitting the multiplexed signal, and a splitter is arranged on the optical channel and is used for splitting an optical signal from the multiplexed signal for monitoring. One end of the optical waveguide is connected with the output end of the splitter, and the other end of the optical waveguide is connected with the optical channel monitor, so that an optical signal split from the multiplexed signal is introduced.

The spectrum modulation chip comprises an optical input port, an optical output port group and a spectrum disturbance structure as shown in fig. 2. The optical input port is used for receiving an optical signal of the optical channel through the optical waveguide; the spectrum disturbance structure is used for receiving the input optical signals input through the optical input ports, carrying out disturbance processing on the input optical signals to obtain a plurality of output optical signals with different optical characteristics, and outputting the output optical signals through the optical output port group. The group of optical output ports comprises at least one optical output port, and a plurality of output optical signals can be output from the same optical output port or respectively from different optical output ports.

The disturbance processing refers to that the input optical signal is changed according to a preset spectral response function after passing through a spectral disturbance structure in the transmission process, so that the power distribution of the output optical signal in the frequency domain is changed. The spectrum disturbance structure is provided with a plurality of spectrum disturbance units (the spectrum disturbance structure of the type is called space spectrum disturbance structure for short) with different spectrum response functions in parallel in space or a spectrum disturbance unit (the spectrum disturbance structure of the type is called time domain adjustable spectrum disturbance structure for short) with the spectrum response functions adjustable in time domain, so that the power distribution of different output optical signals in the frequency domain is different, namely each output optical signal is unique. The spectral response function may be implemented by designing different parameters of the spectral perturbation structure.

The disturbance processing can be one time or multiple times, when the disturbance is performed for multiple times, different outputs are generated for each disturbance through setting parameters, and along with superposition of the disturbance times (under the condition of setting different parameters, including the sequence of the disturbance), the power distribution of each output optical signal on a frequency domain has high-intensity randomness, and the multiple output optical signals also have high irrelevance. While the bandwidth of the spectral perturbation structure is greater than or equal to the full bandwidth of the optical signal in order that the spectral perturbation structure can change the power distribution of the output optical signal over its entire frequency domain (bandwidth).

The following description is given for examples of the time-domain tunable spectrum disturbance structure and the space-type spectrum disturbance structure, respectively.

As shown in fig. 3, a time-domain tunable spectral perturbation structure is shown, the spectral perturbation structure comprising three or more cascaded active tunable spectral perturbation units, the set of light output ports being provided with one of the light output ports, the plurality of cascaded active tunable spectral perturbation units being arranged on the light transmission path between the tube input port and the light output port.

In this embodiment, the optical (signal) transmission paths of the spectrum perturbation structure are only illustrated by one path, and according to practical situations, those skilled in the art can flexibly set the number of optical transmission paths, and the corresponding number of cascaded active tunable spectrum perturbation units and optical output ports, which are not limited herein.

The active tunable spectrum disturbance units are connected in series, different disturbances are generated in time sequence according to the tuning of the control signals, and therefore the optical output ports output a plurality of different output optical signals at different moments.

In particular, as shown in fig. 4, one embodiment of an active tunable spectral perturbation unit is shown, which is an active asymmetric mach-zehnder interferometer 1 having two tuning arms 12 of unequal length and a phase modulator 3 arranged on at least one of the tuning arms 12. The asymmetric Mach-Zehnder interferometer is formed into an asymmetric structure by two tuning arms of unequal arm lengths. The phase modulator actively tunes the phase of the optical signal entering the tuning arm according to the control signal so as to adjust the power distribution of the output optical signal in the frequency domain.

Preferably, the phase modulator has at least three different phase adjustment states, and the three mach-zehnder interferometers can make the optical output port group of the spectrum disturbance structure output 27 different output optical signals.

It should be noted that, there is an arm length difference between the two tuning arms of the active asymmetric mach-zehnder interferometers, and the plurality of active asymmetric mach-zehnder interferometers respectively have different arm length differences. For example, the arm length difference of two interference arms in the three-stage asymmetric Mach-Zehnder interferometer can be sequentially set to 300um, 500um and 800um to improve the random disturbance effect.

For DWDM (dense wavelength division multiplexing) channel monitoring applications, the arm length difference of the asymmetric mach-zehnder interferometer is between 300 and 2000 um; for CWDM (coarse wavelength division multiplexing) channel monitoring applications, the arm length difference of the asymmetric Mach-Zehnder interferometer is between 100 and 1000 um. Those skilled in the art can flexibly set according to practical situations, and are not limited.

More specifically, the active asymmetric mach-zehnder interferometer further includes a first waveguide light splitting element disposed on an input side of the tuning arm and a second waveguide wind-solar element disposed on an output side of the tuning arm. The first waveguide splitting element is used for splitting an input optical signal into two paths according to a preset splitting ratio and respectively inputting the two paths of the input optical signal into the two tuning arms, and the second waveguide splitting element is used for combining output lights of the two tuning arms (also referred to as interference arms) so as to generate optical interference (namely, form disturbance).

Wherein the first waveguide splitting element and the second waveguide splitting element have a splitting ratio of 0.05 to 0.3. The first waveguide splitting element and the second waveguide splitting element located in different mach-zehnder interferometers may have the same splitting ratio or may be different, without limitation.

In the adjacent two-stage asymmetric mach-zehnder interferometer, the output light of the second waveguide light-splitting element in the upper stage is completely used as the input light of the first waveguide light-splitting element in the lower stage. In the adjacent two-stage asymmetric mach-zehnder interferometers, the second waveguide spectroscopic element in the previous-stage asymmetric mach-zehnder interferometer and the first waveguide spectroscopic element in the next-stage asymmetric mach-zehnder interferometer may multiplex the same waveguide spectroscopic element.

In particular, as shown in fig. 5, another embodiment of an active tunable spectral perturbation unit is shown, the active tunable spectral perturbation unit is a micro-loop filter 2 with a resonant structure 21, a phase modulator 3 is arranged in the resonant structure of the micro-loop filter, and the phase modulator tunes the phase of an optical signal entering the resonant structure according to the control signal so as to adjust the power distribution of the output optical signal in the frequency domain. The micro-rings of the plurality of micro-ring filters have different circumferences, respectively.

It should be noted that, for DWDM (dense wavelength division multiplexing) channel monitoring applications, the ring length of the micro-ring resonator (resonant structure) is between 150 and 2000 um; for CWDM (coarse wavelength division multiplexing) channel monitoring applications, the ring length of the micro-ring resonator is between 100 and 1000 um. Those skilled in the art can flexibly set according to practical situations, and are not limited.

Furthermore, the person skilled in the art may combine the embodiments of the two active tunable spectral perturbation units described above to obtain the structure as in fig. 6.

As shown in fig. 7, a spatial type spectrum perturbation structure is shown. The spectrum perturbation structure comprises a plurality of light path components, such as 16, 32 and 64, and the spectrum perturbation structure can be specifically adjusted according to the number and the interval of channels in the optical signal without limitation. The optical path components are connected with the optical input ports through optical splitters, the optical input ports and the optical path components are connected in parallel through the 1*N splitters, and N is the number of the optical path components.

The optical path components comprise three or more cascaded passive spectrum disturbance units, and a plurality of passive spectrum disturbance units in different optical path components have different spectral responses so that a plurality of optical path components generate different disturbance on the input optical signal. The optical output port group comprises a plurality of optical output ports, the optical output ports are in one-to-one correspondence with the optical path components, and a plurality of different output optical signals are output, wherein the power distribution of the different output optical signals in the frequency domain is different.

Specifically, the passive spectrum disturbance unit is a passive asymmetric Mach-Zehnder interferometer or a micro-ring filter with a resonance structure. Unlike active tunable spectrum disturbance unit, passive asymmetric Mach-Zehnder interferometer and micro-ring filter with resonant structure have no phase modulator, and can not actively adjust disturbance parameters, but can only produce according to designed known parameters during production, and achieve the same effect as active tunable spectrum disturbance unit by spatially splitting light and connecting a certain number of light path components in parallel.

It should be noted that, those skilled in the art may also use a hybrid spectrum perturbation structure, that is, a spatial spectrum perturbation structure, and an optical path component is additionally provided, where, unlike other optical path components, the optical path component includes a plurality of cascaded active tunable spectrum perturbation units (specific embodiments may refer to a time-domain tunable spectrum perturbation structure), so as to implement a combination of the time-domain tunable spectrum perturbation structure and the spatial spectrum perturbation structure. The spectrum disturbance structure can be flexibly set according to actual conditions by a person skilled in the art, and the method is not limited.

The photodetector receives the highly random output optical signal output by the optical output port for converting the optical power of the output optical signal into a corresponding electrical signal. The photodetectors may be in one-to-one correspondence with the optical output ports, or may be a plurality of optical output ports time-division multiplexing the same photodetector, without limitation.

The photodetector may be an InGaAs detector or a germanium detector. The germanium detector can be integrated on the same single chip as the spectrum modulation chip, and is not limited.

For the spatial spectrum disturbance structure, the signal processor is provided with an input end and an output end, wherein the input end of the signal processor receives the electric signal corresponding to the output optical signal, and the output end of the signal processor outputs a required monitoring result after the processing. The monitoring result may be that the electrical signal is converted into a corresponding digital signal, the digital signal records spectral data of an output optical signal, or a spectrum of an input optical signal obtained after performing spectral calculation reconstruction on the digital signal.

For the spectrum disturbance structure comprising the time domain adjustable type, the signal processor further comprises a control end, wherein the control end is electrically connected with the spectrum disturbance structure and is used for respectively controlling the phase modulator to finish different phase adjustment according to a preset control signal so that the output ports output different output optical signals.

The input end of the signal processor is used for processing the output signal of the photodetector (provided with a signal amplifying circuit, an analog-to-digital conversion circuit and the like). The signal processor may integrate a computational function and may be used to reconstruct the spectrum of the recovered optical signal without limitation. Likewise, the signal processor may be integrated on the same monolithic chip as the photodetector, the spectral modulation chip.

For implementing phase modulation by thermal tuning or electrical tuning, an electrical drive module is also required at the control end of the signal processor and the phase modulator.

The spectrum modulation chip adopts a planar optical waveguide chip, the waveguide materials of the chip comprise a silicon nitride waveguide, a silicon oxide waveguide, a thin film lithium niobate waveguide, a polymer waveguide and the like, and the spectrum disturbance structure based on a Mach-Zehnder interferometer and the spectrum disturbance structure based on a micro-ring filter can be manufactured on the chip by using the materials.

The optical channel monitor in this embodiment monitors the optical signal in the optical channel using the basic principle of a computational reconstruction spectrometer. The basic principle of the computational reconstruction spectrometer is that an input spectrum is led into a plurality of wide spectrum filter arrays calibrated in advance (namely, spectrum modulation chips in the embodiment can generate different spectrum responses in time sequence or space through tuning, and the function of the wide spectrum filter arrays can be achieved), and the light intensity of the spectrum after being filtered is detected by a corresponding number of photodetectors. And constructing a system of underdetermined equations, namely a spectrum reconstruction matrix by using the intensity information, and carrying out inverse solution by using a related algorithm, such as a convex optimization algorithm, a machine learning algorithm and other mathematical algorithms, so as to obtain the information of the input spectrum. The method has the advantages that a larger number of pixel points of the spectrum in the frequency domain can be solved by using a smaller number of filters and photoelectric detector groups, so that the system volume, cost and computational complexity can be effectively reduced while the hyperspectral detection performance is obtained.

From a mathematical point of view, to achieve an ideal spectral detection effect, such a filtering structure is required to fulfil the following two conditions: (1) The spectral response of each channel needs to have a small autocorrelation coefficient, thereby realizing high resolution; (2) The channels need to have smaller cross-correlation coefficients, so that the uncorrelation of spectrum sampling is ensured; a high-intensity random disturbance can be generated on the frequency domain, so that an effective underdetermined equation set (namely a spectrum reconstruction matrix) can be constructed and solved when the computational spectrometer is used.

The spectrum modulation chip in the embodiment can generate different spectrum responses through a spectrum disturbance structure, so that the output spectrum can generate high-intensity random disturbance on a frequency domain. Because the spectrum disturbance structure is provided with the phase modulators, each phase modulator can modulate phases with different sizes, the spectrum modulation chip can generate different spectrum responses in the time domain by arranging the reasonable number of the spectrum disturbance structures and the reasonable number of the phase modulators with the adjustable gears in order (the number of the spectrum modulation chip is equal to that of the filters far exceeding the number of the equation sets in the equation sets).

The working principle of the optical channel monitor (taking time domain type as an example) in this embodiment is as follows: by designing the spectral perturbation structure of the spectral modulation chip as a cascade of a plurality of (micro-ring) filter/(mach-zehnder) interferometer structures, each filter/interferometer can be modulated individually, after multistage filtering/interference, the input spectrum (optical signal) will be perturbed to an approximately irregular spectral output, and different modulation configurations will have different perturbation characteristics and output spectra.

The disturbance characteristics of the optical fiber array are changed after each modulation configuration is changed, the output of each photoelectric detector corresponds to one modulation, and the disturbance characteristics under each modulation configuration, namely the spectral response function is Ti (lambda) (i=1, 2,., M), wherein M is the modulation times, and the output of the photoelectric detector is as follows:

I _t ＝∫T _i (λ)Φ(λ)dλ

the plurality of response functions may be denoted as a disturbance characteristic matrix, and the plurality of photodetector results may be denoted as a column vector:

I _M×1 ＝T _M×N Φ _N×1 i.e. a spectral reconstruction matrix, or a system of underdetermined equations.

Where N is the number of wavelength pixels.

Known column vector I _M×1 And a transmission characteristic matrix T _M×N In the case of (a), the spectrum Φ of the input signal can be obtained by a reconstruction algorithm _N×1 。

The designed spectrum disturbance structure is matched with a corresponding reconstruction algorithm, and the input spectrum can be reliably reconstructed with the wavelength resolution of tens of picometers by only needing tens to hundreds of times of modulation.

Meanwhile, as shown in fig. 8, the present embodiment also provides an optical channel monitoring method in the second aspect, including but not limited to the following steps.

S100: and sending a control signal to the spectrum modulation chip to acquire a plurality of different output optical signals corresponding to the input optical signals.

The number of channels in the optical signal determines the number of samples over the wavelength range and the minimum resolution. When the number of channels in the optical signal is small, the number of sampling points can be set correspondingly small, and meanwhile, the number of the underdetermined equation sets required to be constructed for reconstructing the spectrum of the optical signal is small, so that the corresponding number of output spectrums are obtained by sending different control signals, and the corresponding underdetermined equation sets are constructed.

S200: the spectral calculation reconstruction is performed on the input optical signal from a plurality of different output optical signals. When constructing a spectral reconstruction matrix (i.e. a system of underdetermined equations), in which the response (i.e. the response function) of the spectral perturbation structure to the spectrum is known, the optical power of a plurality of different output optical signals is acquired by means of the photodetector, and is also known, so that the optical power of the output optical signals at the respective sampling points can be solved.

S300: a spectrum of the input optical signal is obtained. And reconstructing the optical power of the solved output optical signal at the sampling point according to the frequency domain to obtain the spectrum of the input optical signal.

However, the spectrum modulation chip is only configured by a pure space type spectrum disturbance structure, and in step S100, a plurality of different output optical signals corresponding to the input optical signals can be directly obtained without transmitting a control signal to the spectrum modulation chip.

As shown in fig. 9, the optical channel monitor and the optical channel monitoring method are adopted to monitor the optical signal with fifty channels, and finally, the spectrum of the output optical signal after the reconstruction is calculated is obtained, as can be seen from the figure, the channels in the reconstructed spectrum almost overlap with the signals in the original spectrum.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that the present invention includes but is not limited to the accompanying drawings and the description of the above specific embodiment. Any modifications which do not depart from the functional and structural principles of the present invention are intended to be included within the scope of the appended claims.

Claims (11)

1. An optical channel monitor comprises a photoelectric detector and a signal processor, and is characterized by further comprising a spectrum modulation chip; the spectrum modulation chip comprises an optical input port, an optical output port group and a spectrum disturbance structure, wherein the optical output port group comprises at least one optical output port, and the spectrum disturbance structure is used for receiving an input optical signal input through the optical input port, carrying out disturbance processing on the input optical signal to obtain a plurality of output optical signals with different optical characteristics and outputting the plurality of output optical signals through the optical output port group; the photoelectric detector is used for converting the optical power of the output optical signal into a corresponding electric signal; the signal processor is used for acquiring related data of spectrums of the input optical signals according to a plurality of the output optical signals.

2. The optical channel monitor of claim 1 wherein the spectral perturbation structure comprises a plurality of cascaded active tunable spectral perturbation units, the signal processor being further configured to generate a control signal; said set of light output ports comprising one of said light output ports; the active tunable spectrum disturbance units are connected in series, different disturbances are generated in time sequence according to the tuning of the control signals, and therefore the optical output ports output a plurality of different output optical signals at different moments.

3. The optical channel monitor of claim 1 wherein the spectral perturbation structure comprises a plurality of optical path components, a plurality of the optical path components being connected to the optical input port by optical splitters, each of the optical path components comprising a plurality of cascaded passive spectral perturbation units, the plurality of passive spectral perturbation units in different of the optical path components having different spectral responses such that the plurality of optical path components produce different spectral perturbations to the input optical signal; the optical output port group comprises a plurality of optical output ports, and the optical output ports are in one-to-one correspondence with the optical path components and output a plurality of different output optical signals; the power distribution of different ones of said output optical signals in the frequency domain is different.

4. The optical channel monitor of claim 1 wherein the spectral perturbation structure comprises a plurality of optical path components, a plurality of the optical path components being connected to the optical input port through an optical splitter; the optical path components comprise a plurality of cascaded spectrum disturbance units, the plurality of spectrum disturbance units in different optical path components have different spectrum responses so that the plurality of optical path components generate different spectrum disturbances on the input optical signal, and the plurality of cascaded spectrum disturbance units of at least one optical path component are a plurality of cascaded active tunable spectrum disturbance units; the signal processor is also used for providing a control signal for tuning of the active tunable spectrum disturbance unit; the optical output port group comprises a plurality of optical output ports, and the optical output ports are in one-to-one correspondence with the optical path components so as to output different output optical signals.

5. The optical channel monitor of claim 2 or 4, wherein at least one of the active tunable optical spectrum perturbation units in the optical spectrum perturbation structure is an active asymmetric mach-zehnder interferometer having two tuning arms of unequal lengths and a phase modulator disposed on at least one of the tuning arms, the phase modulator tuning the phase of an optical signal entering the tuning arms in accordance with the control signal to adjust the power distribution of the output optical signal in the frequency domain.

6. The optical channel monitor of claim 5, wherein there is an arm length difference between two tuning arms of the active asymmetric mach-zehnder interferometer; the plurality of active asymmetric mach-zehnder interferometers each have a different arm length difference.

7. The optical channel monitor of claim 2 or 4, wherein at least one of the active tunable spectral perturbation units in the spectral perturbation structure is a micro-loop filter with a resonant structure, and a phase modulator is arranged in the resonant structure of the micro-loop filter, and the phase modulator tunes the phase of the optical signal entering the resonant structure according to the control signal to adjust the power distribution of the output optical signal in the frequency domain.

8. The optical channel monitor of claim 7 wherein the micro-rings of a plurality of said micro-ring filters each have a different circumference.

9. The optical channel monitor of claim 3 or 4, wherein at least one of the passive spectral perturbation unit or the spectral perturbation unit in the spectral perturbation structure is a passive asymmetric mach-zehnder interferometer or a micro-ring filter with a resonant structure.

10. An optical channel monitoring method, comprising:

acquiring a plurality of different output optical signals corresponding to the input optical signals;

performing spectral calculation reconstruction on the input optical signal according to a plurality of different output optical signals;

a spectrum of the input optical signal is obtained.

11. The optical channel monitoring method according to claim 10, further comprising, before the step of acquiring a plurality of different output optical signals corresponding to the input optical signals, transmitting a control signal to a spectrum modulation chip; wherein the number of the plurality of different output light signals is related to the control signal.