WO2018236132A1 - Optical wavelength channel analyzer - Google Patents

Abstract

The present invention relates to an optical wavelength analyzer for analyzing an optical signal wavelength including a plurality of wavelengths transmitted by an optical transmitter in a wavelength division multiplexing optical network. The optical wavelength analyzer of the present invention includes an optical input unit, an optical unit, a control unit, a signal processing unit, and a display unit, wherein: the optical input unit receives an optical signal including a plurality of optical wavelengths so as to transmit the optical signal to the optical unit as two optical signals; the optical unit filters the two optical signals, transmitted from the optical input unit, for each of a coarse wavelength division multiplexing (CWDM) channel and a dense wavelength division multiplexing (DWDM) channel by using a CWDM channel filter and a DWDM channel filter attached to a rotating plate, and outputs an electrical signal proportional to the optical intensity of a wavelength corresponding to each channel; the control unit controls the rotation angle of the rotating plate of the optical unit; the signal processing unit generates a rotation angle control signal for the control unit, and extracts a wavelength-specific optical intensity value on the basis of the rotation angle and the electrical signal; and the display unit can display the wavelength-specific optical intensity value extracted by the signal processing unit. To this end, the present invention allows a first channel filter including a plurality of filters to be attached at regular intervals in parallel with a tangent in the rotation direction of the rotating plate, such that an incident angle of an optical signal inputted to the first channel filter changes when the rotating plate rotates, thereby enabling one of the first channel filters to measure a plurality of channels, and allows a second channel filter including a plurality of filters to be attached perpendicularly in the circumferential direction to a tangent in the rotation direction of a rotating motor such that an incident angle of an optical signal inputted to the second channel filter does not change even when the rotating plate rotates, thereby enabling one of the second channel filters to measure only one channel, and thus the present invention can simultaneously measure a DWDM optical signal and a CWDM optical signal by means of one measuring device.

Description

Optical wavelength channel analyzer

The present invention relates to an optical wavelength channel analyzer, and more particularly, to an optical wavelength channel analyzer for measuring and analyzing a wavelength included in an optical signal transmitted from an optical transmitter in a wavelength division multiplexing optical network.

Wavelength division multiplexing (WDM) is a technique that transmits a plurality of optical wavelength signals to a single optical fiber at a time, so that it can transmit a large amount of data without using additional optical cables. Since it is a more economical method than the time division method, most wavelength division multiplexing (WDM) systems are applied to the present optical network.

  There are two broad categories of wavelength division multiplexing schemes. Coarse Wavelength Division Multiplexing (hereinafter referred to as CWDM) can transmit optical signals of up to 18 channels by dividing a wavelength in a range of wavelengths from 1270 nm to 1610 nm at intervals of 20 nm, and a high-density wavelength division multiplexing Dense Wavelength Division Multiplexing (hereinafter referred to as DWDM) can transmit 40 to 80 channel signals by dividing the 1530 nm to 1565 nm band (C-band) at intervals of approximately 0.8 nm (100 GHz) or approximately 0.4 nm (50 GHz) . In addition to the C-band, the DWDM band can be divided into the O-band (1260 to 1360 nm, 100 nm), E-band (1360 to 1460 nm, bandwidth 100 nm), S-band (1460 to 1530 nm, To 1625 nm and a bandwidth of 60 nm) and a U-band (1625 to 1675 nm, bandwidth of 50 nm), and the wavelength division method is a very effective communication method for increasing the data transmission capacity. In addition, the wavelength division method is also used in LAN-WDM using 4 wavelengths with a channel interval of 5 nm established by IEEE 802.3ba.

  Although wavelength division multiplexing has the advantage of economically transmitting large amounts of data, since a plurality of optical signals share one optical fiber, if the wavelength of the optical transmitter laser applied to the WDM scheme is out of the allowable range of the allocated channel It may cause transmission error of data. Therefore, it is essential to measure the wavelength of the optical signal as well as the intensity of the optical signal (optical output) in order to install, maintain and repair the wavelength division multiplexing system.

  In recent years, the construction of optical communication networks has been cost-effective by implementing CWDM channels and DWDM channels in a single optical fiber cable, transmitting large-capacity data over DWMD channels and low-capacity data over CWDM channels Of the population. In order to maintain the optical line including the CWDM channel and the DWDM channel, a meter capable of measuring both the optical wavelength and the optical output of the CWDM and the DWDM channel is essential.

  An optical spectrum analyzer (OSA) can be used to obtain the wavelength information of the optical signal to be transmitted. The optical spectrum analyzer can measure very precisely with a wavelength resolution of 0.02 nm, and the CWDM channel and the DWDM channel are combined The wavelength and light intensity of the optical signal can be measured, but it is bulky, heavy, and expensive. Therefore, the optical spectrum analyzer is not suitable for outdoor use where optical cable installation / maintenance / repair work is performed.

  As a conventional wavelength measuring technique for a portable WDM optical communication network, there is a registered patent No. 10-0820947. However, these optical wavelength output measuring devices are DWDM dedicated measuring devices or CWDM dedicated measuring devices, respectively, which can not measure optical signals in which CWDM and DWDM are combined .

  1 is a configuration diagram of an optical part of a conventional optical wavelength output measuring device.

  Referring to FIG. 1, in a conventional optical wavelength output measuring apparatus disclosed in Patent Document 10-0820947, an optical signal including a plurality of channels passes through a collimator lens 20 and a channel filter 31 and is incident on a photodetector 40 And a stepping motor 33 measures the light intensity of each optical signal including a plurality of channels while rotating the rotating plate 32 with the channel filter 31 attached thereto. This method can be measured only when the input optical signal is a CWDM channel, and the optical intensity of the optical signal of the DWDM channel can not be measured.

An object of the present invention to solve the above problems is to provide an optical wavelength channel analyzer capable of measuring both CWDM and DWDM signals in a wavelength multiplexed optical communication, especially in a wavelength multiplexed optical communication network in which CWDM and DWDM optical signals are mixed .

According to an aspect of the present invention, there is provided an optical wavelength analyzer for analyzing a wavelength and intensity of each wavelength included in an optical signal according to the present invention includes an optical input unit, an optical unit, a control unit, a signal processing unit, The input unit receives an optical signal including a plurality of optical wavelengths and transmits the optical signal to the optical unit through two optical signals. The optical unit includes a plurality of optical filters The optical signal processing apparatus according to any one of claims 1 to 3, wherein the optical signal processing unit is configured to filter the two optical signals by channels and to output an electric signal proportional to the light intensity of the wavelength corresponding to each channel, Generating a rotation angle control signal, extracting an optical intensity value for each wavelength based on the rotation angle and the electrical signal, Play unit can display the light intensity value by the wavelength extracted by the signal processing unit.

The optical unit may include a first lens and a second lens that convert the two optical signals from the optical input unit into parallel light, a first channel filter that filters the first parallel light from the first lens, A second channel filter for filtering the second parallel light coming from the first channel filter, a rotating plate to which the first channel filter and the second channel filter are attached, a motor for rotating the rotating plate, And a second photodetector converting the parallel light having passed through the second channel filter into a second electrical signal and outputting the converted second electrical signal.

The first channel filter is attached parallel to the tangent of the rotation direction of the rotation plate so that the angle at which the first parallel light enters the first channel filter changes according to the rotation of the rotation plate, The filter may be attached in a circumferential direction perpendicular to the tangent of the rotation direction of the rotation plate so that the angle at which the second parallel light enters the second channel filter does not change according to the rotation of the rotation plate. In this case, the first channel filter may be a CWDM channel filter for filtering a CWDM channel, and the second channel filter may be a CW band, a 0 band, an E band, an S band, an L band, a U band DWDM Channel, and a LAN-WDM channel. The first channel filter and the second channel filter may be attached in parallel to the tangent of the rotating direction of the rotating plate so that an angle at which the first parallel light enters the first channel filter in accordance with the rotation of the rotating plate And an angle at which the second parallel light enters the second channel filter may be changed. In this case, the first channel filter and the second channel filter may have different CWDM channels, C-band, 0-band, E-band, S-band, L- A DWDM channel, and a LAN-WDM channel.

In addition, the first channel filters may be classified into one or more groups, and each group may be composed of a plurality of filters having the same bandwidth, and the transmission bandwidth may be different or the wavelength band to be filtered may be different among the groups, The first channel filter is composed of seven C-band filters, and the filtered center wavelengths of the respective filters of the seven filters are between 1530 nm and 1565 nm. The interval between the filtered central wavelengths of the respective filters is 6 nm And the second channel filters can be classified into one or more groups and each group is composed of a plurality of filters having the same bandwidth, the transmission bandwidths of the groups may be different or the wavelength bands may be different from each other, , The second channel filter is composed of 18 filters, and the filtered center wavelength of each filter of the 18 filters is between 1270 nm and 1610 nm , The distance between the center wavelength of the filter of each filter may be 20nm.

The signal processing unit may be configured to generate a signal at a point where the electric signal changes from a high point that is greater than a preset reference value to a low point that is smaller than the predetermined reference value or that the electric signal changes from a low point lower than the preset reference value to a high point The wavelength value included in the optical signal can be extracted based on the rotation angle of the optical signal.

The optical input unit includes an optical input interface for receiving the optical signal and an optical splitter for splitting the optical signal received through the optical input interface into two optical signals, Each of the optical signals may be incident on the first lens and the second lens.

The optical input unit may include one optical input interface for receiving the optical signal, an optical splitter for splitting the optical signal received through the optical input interface into two optical signals, And reflects the wavelength band of the second channel filter; and

And an optical switch for receiving and outputting any one of an optical signal reflected from the filter module and an optical signal coming from the optical splitter, wherein the output of the filter module is transmitted to the first lens, And can be transmitted to the second lens.

 In the present invention, the first channel filter is attached parallel to the tangent of the rotation direction of the rotation plate, so that the angle of incidence (AOI) of light incident on the channel filter may change as the rotation plate rotates, The second channel filter is attached in a circumferential direction perpendicular to the tangential line of the rotating plate of the rotating plate so that the angle of incidence of the light entering the channel filter does not change as the rotating plate rotates, And the intensity is measured.

 The signal processing unit may include a nonvolatile memory capable of storing a change value of the transmission characteristic of the channel filter for each rotation angle of the rotation plate, and stores a transmission spectrum corresponding to an incident angle (AOI) for each channel filter, And is used for calculating the wavelength of the input light from the output signal of the detector.

According to the present invention, accurate information on the wavelength value of an optical signal is provided in a bar-wavelength multiplexed optical communication system capable of precisely measuring the wavelength of the received optical signal and capable of measuring the output of the optical signal, And it is possible to facilitate the maintenance and repair process of the optical communication network.

1 is a configuration diagram of an optical part of a conventional optical wavelength output measuring device.

2 is a diagram showing a spectrum of a light channel used in an optical communication of a wavelength multiplexing scheme.

3 is a diagram illustrating a configuration of an optical wavelength channel analyzer according to an embodiment of the present invention.

4 is a diagram illustrating the structure of an optical unit 200 of an optical wavelength channel analyzer according to an embodiment of the present invention.

5 is a diagram showing the structure of an optical part 200 of an optical wavelength channel analyzer according to another embodiment of the present invention.

FIG. 6 is a graph showing a change in a filtered wavelength according to a change in an incident angle. FIG.

7 is a graph showing the relationship between the optical signal 213 and the optical signal 213 when the optical signal 213 is incident at the center of the filter 230a at an incident angle of 0 degrees when the wavelength is measured while rotating one channel filter, 720 which can rotate the filter 230a to the maximum.

8 is a graph showing the relationship between the angle of incidence φ of the motor 260 and the angle of incidence of the filter of one of the filters included in the DWDM channel filter 230 and the CWDM channel filter 240, And the wavelength of the transmission band is changed.

9 is a view for explaining a method of measuring a wavelength of an input optical signal according to an embodiment of the present invention.

10 is a view for explaining a method of measuring a wavelength of an input optical signal according to another embodiment of the present invention.

11 is a diagram illustrating an embodiment in which 100 GHz DWDM is applied to the C-band (1530 to 1565 nm, bandwidth: 35 nm).

12 is a graph showing a relationship between an incident angle and a wavelength displacement of a DWDM filter having a center wavelength of 1570 nm and an effective refractive index (n _eff ) of 1.5764.

13 is a diagram illustrating a configuration of a light input unit 100 according to an embodiment of the present invention.

14A and 14B are diagrams showing the configuration of a light input unit 100 according to another embodiment of the present invention.

15A and 15B are diagrams showing a configuration of a light input unit 100 according to another embodiment of the present invention.

16A and 16B are views showing the configuration of a light input unit 100 according to another embodiment of the present invention.

Figs. 17A to 17D and Figs. 18A to 18D are diagrams showing the configuration of a light input unit 100 according to another embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

  Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when a part is referred to as " including " an element, it does not exclude other elements unless specifically stated otherwise.

  If any part is referred to as being " on " another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being " directly above " another section, no other section is involved.

  The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

  The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

  Terms indicating relative space such as " below ", " above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain portions that are described as being " below " other portions are described as being " above " other portions. Thus, an exemplary term " below " includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

  Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

2 is a diagram showing a spectrum of a light channel used in an optical communication of a wavelength multiplexing scheme.

In FIG. 2, eighteen CWDM channels 901, 902, and 903 having a wavelength interval of 20 nm and 48 100G DWDM channels 910 having a wavelength interval of 0.8 nm are used in the optical communication of the wavelength multiplexing type optical communication. Respectively. For example, if a certain optical communication network is constructed by a CWDM type wavelength multiplexing method, since there are only 18 CWDM channel optical signals in one optical fiber line, a general CWDM wavelength power measuring device is used, Can be measured. In addition, if it is constructed using DWDM only, the optical output of each optical channel can be measured by using a general DWDM wavelength power meter.

 However, if the CWDM channels 901 and 903 and the DWDM channel 910 are multiplexed as shown in FIG. 2 (the CWDM channel 902 may not be used because the CWDM channel 902 may interfere with the DWDM channel 910) With the CWDM meter, the CWDM channels 901 and 903 can be measured but the DWDM channel 910 can not be measured. In addition, a DWDM channel 910 can be measured by a general DWDM measuring device, but the CWDM channels 901 and 903 can not be measured.

  The present invention is an optical wavelength channel analyzer capable of measuring both the wavelengths of the CWDM channels 901 and 903 and the DWDM channels 910 in the optical communication network in which the CWDM channel and the DWDM channel are combined, .

3 is a diagram illustrating a configuration of an optical wavelength channel analyzer according to an embodiment of the present invention.

3, an optical wavelength channel analyzer according to an exemplary embodiment of the present invention includes an optical input unit 100, an optical unit 200, a control unit 300, a signal processing unit 400, and a display unit 500 can do. The optical input unit 100 transmits an optical signal including a plurality of optical wavelengths inputted from the outside to the optical unit 200. The optical unit 200 analyzes the wavelength and the output of the inputted optical signal, The control unit 300 controls the rotation angle of the motor 260 in the optical unit 200 and the signal processing unit 400 generates the rotation angle control signal for the control unit 300, Extracts the light intensity at the wavelength included in the optical signal and the wavelength from the rotation angle, the A / D-converted output waveform, and the magnitude of the output signal, 500 may be configured to display the measured wavelength and the light intensity at that wavelength.

3, the optical unit 200 includes two collimating lenses 210 and 220 for converting input optical signals into parallel light, and a plurality of collimating lenses 210 and 220, A rotary plate 250 attached with two channel filters 230 and 240 and two channel filters 230 and 240 for filtering and rotated by the start of the motor 260, A motor 260 for rotating the optical fibers 250 and 250 and two photodetectors 270 and 280 for converting optical signals having passed through the two channel filters 230 and 240 into electrical signals.

4 is a diagram illustrating the structure of an optical unit 200 of an optical wavelength channel analyzer according to an embodiment of the present invention.

4, the center of rotation plate 425 is coupled with the rotation axis 261 of motor 426 and rotates together with rotation axis 261, . The two channel filters 230 and 240 may be a DWDM channel filter and a CWDM channel filter. In more detail, the first channel filter 230 may include a plurality of filters, In particular, each filter can filter some of the DWDM channel wavelengths, and the second channel filter 240 also includes a plurality of filters, each capable of filtering only a different specific wavelength, One can be designed to filter. Particularly, in the case of the first channel filter 230 for filtering a DWDM channel, at least one of C-band, 0-band, E-band, S-band, L- Channel filter. Each filter of the first channel filter 230 may be attached perpendicularly to the protruding concentric circles 251 of the rotary plate 250 so that they are vertically attached to each other at regular intervals on an equally spaced, And each filter of the second channel filter 240 can be attached to the outer circumference of the disk of the turntable 250 in parallel with the turntable 250. The filters of the second channel filter 240 can be equally spaced from each other, Lt; / RTI > One of the two optical signals transmitted from the optical input unit 100 passes through the first channel filter 230 and reaches the photodetector 270 and the other optical signal transmitted from the optical input unit 221 can reach the photodetector 280 through the second channel filter 240.

4, the first channel filter 230 is vertically attached to the rotary plate 250 and passes through the collimating lens 210 as the rotary plate 250 is rotated by the motor 260, The incident angle of the converted optical signal 213 can be changed. On the other hand, the second channel filter 240 is attached to the rotating plate 250 in parallel so that even when the rotating plate 250 rotates, light passing through the collimating lens 220 and incident from the optical signal 223 converted into parallel light The angle of incidence of the signal is not changed but always becomes 90 degrees.

  Each of the plurality of filters included in the first channel filter 230 and the second channel filter 240 may be designed to have different filtering center wavelengths. In one embodiment, when the first channel filter 230 is used as a channel filter for 100G DWDM, the first channel filter 230 may have a center wavelength of about 0.8 nm between 1525 nm and 1570 nm, And may include a plurality of filters, and each filter may be a filter that passes only light corresponding to its center wavelength and does not pass light of the remaining wavelengths. Or the first channel filter 230 may include a plurality of filters having a center wavelength of 6 nm intervals and a bandwidth of 0.3 nm between 1525 nm and 1570 nm. In this case, the presence or absence of a plurality of DWDM channel wavelengths Measurement and analysis. When the second channel filter 240 is used as a CWDM channel filter, it can be designed to include a plurality of filters having a center wavelength of 1270 nm to 1610 nm and a center wavelength of 20 nm and a bandwidth of 14 nm.

 The plurality of filters included in the first channel filter 230 and the second channel filter 240 may be attached to the rotary plate 250 at equal intervals as described above. In one embodiment, the first channel filter 240, which includes 16 filters, may be attached to the rotating plate 250 with an interval of 360/16 = 22.5 degrees.

 5 is a diagram showing the structure of an optical part 200 of an optical wavelength channel analyzer according to another embodiment of the present invention.

5 and FIG. 4, the protruding concentric circles of FIG. 4 are provided at the outermost side of the disc to form a 'C' shape when the cross section is cut away. The first channel filter 240 attached to the rotary plate 250 in the circumference of the circular plate 4 is vertically attached to the rotary plate 250 on the outer side of the concentric circle. The optical signal 221 that is introduced from the outside with the hole 251 in the portion where the second concentric channel filter 240 is attached passes through the collimating lens 220, 240 pass through a hole 251 formed in a projecting concentric circle of the rotary plate 250 through a second channel filter 240 and are finally incident on a photodetector 280.

The first channel filter 230 and the second channel filter 240 of FIG. 5 filter CWDM, C-band, 0-band, E-band, S-band, L- U-band DWDM, and LAN-WDM. That is, the first channel filter 230 and the second channel filter 240 each include a plurality of filters, which may be classified into one or more groups, and each group may include one or more Filter, and the transmission bandwidth may be different between the groups or the wavelength band to be filtered may be different. As an example, the first channel filter 230 or the second channel filter 240 may include 11 filters in total, and the 11 filters may be divided into three groups, the first group being a wideband filter The second group includes three filters with a filtering bandwidth equal to 14 nm and a center filtering wavelength of 1570 nm, 1310 nm and 1490 nm, respectively, with a CWDM channel filter, , A third group is a DWDM channel filter, one filter for measuring the wavelength in the 1550 to 1560 nm band, one filter for measuring the wavelength in the 1580 nm band, one filter for measuring the wavelength in the 1602 nm band, A filter for measuring the wavelength of 1544 bands, and a total of 6 filters. As described above, the first channel filter 230 and the second channel filter 240 may be configured by various combinations of filters to measure wavelengths in various regions.

When analyzing an optical signal by vertically attaching the filters to the rotary plate 250 like the first channel filter 230 of FIG. 4 or the second channel filter 240 and the first channel filter 230 of FIG. 5, The wavelength included in the signal can be more precisely analyzed and the entire channel can be measured using a smaller number of filters than the number of channels.

As an example, in the case of a CWDM channel, each channel may have a central wavelength of 12 nm to 1610 nm at 20 nm intervals, and each channel band may have 20 nm. Each filter of the second channel filter 240 can pass a band of 7 nm on both sides of the center wavelength (for example, a band of 1483 nm to 1497 nm if the center wavelength is 1490 nm). However, even if the optical wavelength transmitted from the optical transmitter is 1491 nm or 1496 nm rather than 1490 nm which is the exact center wavelength due to various factors including the surrounding environment, the optical output is received in the photodetector through the filter in all of the channel bandwidth. It can be determined that the optical wavelength has been introduced. However, it is not known how far the optical wavelength is from the center wavelength. That is, when the filters are horizontally attached to the rotary plate 250 as in the second channel filter 240 of FIG. 4, it is not possible to measure the exact wavelength of the optical wavelength, and only the center wavelength can be determined. On the other hand, in the case of vertically attaching to the rotary plate 250, the wavelength included in the incoming light can be analyzed precisely.

Hereinafter, the operation of the signal processing unit 400 for accurately analyzing the wavelength included in the incoming light when the filter is vertically attached to the rotating plate 250 will be described.

Generally, a thin film filter can change a wavelength to be filtered according to a change in the incident angle of light. The value of the changed wavelength has the following relationship.

Here,? _O is the center wavelength of the filter when the incident angle of light is 0 degree _{,? Represents the} incident angle, and _neff represents the effective refractive index of the thin film filter.

In addition, the change of the filtered wavelength when the incident angle changes by 1 degree at the incident angle? Has a relation of (2).

FIG. 6 is a graph showing a change in a filtered wavelength according to a change in an incident angle. FIG.

6 is a graph illustrating a relationship between a change amount of a wavelength 610 filtered by a thin film filter 610 and an incident angle 610 at a specific incident angle when the incident angle increases from 0 to 14 degrees in a thin film filter having a center wavelength of 1550 nm and an effective refractive index of 2.0, 620 < / RTI > of the wavelength to be filtered in the case where the frequency is changed by 1 more. Referring to FIG. 6, when the angle of incidence of the light on the thin film filter is changed from 0 to 10 degrees, the wavelength to be filtered by about 6 nm is changed. When the incident angle is controlled to be 10 degrees in a filter designed to have an incident angle of 0 degrees and a center wavelength of 1550 nm, the central wavelength to be filtered is changed from 1550 nm to 1544 nm. Referring to FIG. 6, when the incident angle is further changed from 10 degrees to 1 degree, a wavelength of about -1.2 nm is displaced. That is, if the incident angle changes from 10 to 11 degrees, the characteristic wavelength of the filter decreases by 1542.8 nm at 1544 nm.

7 is a graph showing the relationship between the optical signal 213 and the optical signal 213 when the optical signal 213 is incident at the center of the filter 230a at an incident angle of 0 degrees when the wavelength is measured while rotating one channel filter, 720 which can rotate the filter 230a to the maximum. The maximum rotation angle 720 can be calculated using Equation (3) by the size of the channel filter and the radius of the rotating plate to which the channel filter is attached.

Where D is the beam diameter of the optical signal 213, R is the distance from the center of rotation of the turntable 250 to the bottom of the filter 230a, t is the thickness of the channel filter (731). The maximum rotation angle [theta] _max is about 6.1 degrees according to Equation (3) when L = 2.0mm, D = 0.3mm, R = 7mm and t = _max ) is equal to the maximum rotation angle, so it is about 6.1 degrees. Therefore, the range of measurable incident angles is φ = -6.1 to +6.1 degrees. According to Equation (1), the center wavelength? _O = 1550 nm, the effective refractive index _neff = 2.0, the displacement 740 of the wavelength becomes 2.2 nm to -2.2 nm.

In the above-described embodiment, although the filter with the effective refractive index value of 2.0 is used as a reference in the wavelength change relation of the formula (1), it is not limited to the filter having the effective refractive index of 2.0. Generally, when designing or fabricating a multilayer thin film laminated filter, the effective refractive index is determined by the refractive index of the dielectrics used in the lamination. According to Equation (1), when the effective refractive index is reduced by 5%, the wavelength displacement is increased by 11%.

1, since the incident angle between the input optical signal and the filter does not change even if the step motor 33 rotates, the conventional optical wavelength power meter does not exhibit the same effect as the present invention, The included wavelength value can not be precisely measured.

3 to 5, the signal processing unit 400 controls the motor 260 through the control unit 300 to rotate the rotating plate 250 to detect electrical signals coming from the photodetectors 270 and 280, The light wavelength included in the signals 213 and 223 can be precisely measured.

Hereinafter, a wavelength measurement method performed by the signal processing unit 400 according to the present invention will be described with reference to FIGS. 8 to 10. FIG.

8 is a graph showing the relationship between the angle of incidence φ of the motor 260 and the angle of incidence of the filter of one of the filters included in the DWDM channel filter 230 and the CWDM channel filter 240, And the wavelength of the transmission band is changed.

The method proposed by the present invention for measuring the wavelength of light included in an input optical signal uses the wavelength (λ _LE ) at the left edge 1020 and the wavelength λ _RE at the right edge 1010 of the transmission band of the filter. 8, when the rotation angle [theta] of the motor is set to be perpendicular to the optical signal 414 to which the filter is incident, that is, when the incident angle [phi] of the optical signals 213 and 223 is set to be 0 , The filter can only pass wavelengths of the designed band at the designed central wavelength ([lambda] _C ). As an example, when the channel filter is designed to pass only a wavelength of? C ± 7 nm, the left edge wavelength? _LE can be? C - 7 nm and the right edge wavelength? _RE can be? C + 7 nm. That is, when the center wavelength? _C is 1550 nm, the left edge wavelength? _LE can be 1543 nm and the right edge wavelength? _RE can be 1557 nm. The right edge 1010 wavelength λ _RE and the left edge 1020 wavelength λ _LE of the transmission band of the filter when the motor 260 is rotated every rotation interval dθ are calculated. When the motor 260 is rotated by dθ, the rotating plate 250 rotates in the same manner, and the filter attached to the projected concentric circle of the rotating plate 250 rotates by dθ. Thus, the incident angle? At which the optical signals 213 and 223 are incident on the filter becomes d ?. When the angle of incidence changes from 0 to d ?, the wavelength band that the filter can pass through changes as described in Fig. As shown in Fig. 8, the right corner wavelength? _REi and the left corner wavelength? _LEi are changed accordingly. Such a change can be calculated using [Equation 1]. The N filters are attached to the protruding concentric circles of the rotary plate 250 and are calculated for M incident angles (0, d ?, 2d ?, ..., (M-1) d?) For each filter, NxM measurement data sets can be obtained. That is, the measurement data set may be a function of θ _k , φ _j , λ _LE (i), λ _RE (i), dλ _LEj , and dλ _REj . Where i is an integer from 1 to N, j is an integer from 1 to M, and k is an integer from 1 to N x M. θ _k is an angular position of the motor between 0 and 360 degrees, and φ _j is an incident angle of the optical signal to the filter, and has a value of 0 to (M-1) dθ. dλ _j D? _REj is the displacement value of the wavelength at the right edge 1010, and d? _LEj is the displacement value of the wavelength at the left edge 1020. As shown in FIG.

For example, if the number of channel filters is 16, d? Is 0.5, and the calculation is performed for 20 incident angles, the total measurement data becomes 16 × 20 = 320. That is, as the number of incident angles to be calculated increases, and as the number of channel filters increases, the amount of measurement data may increase. On the other hand, the accuracy of the measurable wavelength can be further increased. Under these conditions, the measurement data may have the values shown in Table 1 below.

k	i	j	θ k	φ j	? LE (i)	? RE (i)	dλ LEj	dλ REj
One	One	One	0	0	1263 nm	1277 nm	0 nm	0 nm
2	One	2	0.5	0.5	1263 nm	1277 nm	-0.012 nm	-0.012 nm
...	...	...	...	...	...	...	...	...
20	One	20	10	10	1263 nm	1277 nm	-4.796 nm	-4.796 nm
21	2	One	22.5	0	1283 nm	1297 nm	0 nm	0 nm
22	2	2	23	0.5	1283 nm	1297 nm	-0.012 nm	-0.012 nm
...	...	...	...	...	...	...	...	...
30	2	10	27.5	5	1283 nm	1297 nm	-1.225 nm	-1.225 nm
...	...	...	...	...	...	...	...	...
40	2	20	32.5	10	1283 nm	1297 nm	-4.871 nm	-4.871 nm
...	...	...	...	...	...	...	...	...
...	...	...	...	...	...	...	...	...
301	16	One	337.5	0	1603 nm	1617 nm	0 nm	0 nm
302	16	2	338	0.5	1603 nm	1617 nm	-0.015 nm	-0.015 nm
...	...	...	...	...	...	...	...	...
320	16	20	347.5	10	1603 nm	1617 nm	-6.080 nm	-6.080 nm

The measurement data may be stored in a nonvolatile memory provided in the signal processing unit 400 of FIG. 3 and used for wavelength measurement.

9 is a view for explaining a method of measuring a wavelength of an input optical signal according to an embodiment of the present invention.

9, when the input optical signal whose wavelength is not known enters the wavelength meter, the signal processor 400 detects the output of the photodetector 270 or 280 so that the input optical signal is included in the input optical signal 213 or 223 The wavelength can be measured. FIG. 9 shows a case in which the optical signals 213 and 223 contain the optical wavelength 1100 corresponding to a specific filter band. If the optical wavelength 1100 is within the transmission band 1110 of the particular filter, the optical wavelength 1100 is transmitted through the filter and transmitted to the photodetectors 270 and 280. The photodetectors 270 and 280 may generate an electric signal corresponding to the intensity of the light wavelength to be transmitted to the signal processor 400. In the case of the conventional optical wavelength detector, it can be confirmed that there is an optical wavelength corresponding to a specific channel by looking at the electric signal emitted from the photodetectors 270 and 280, but the precise wavelength of the actually transmitted optical wavelength can not be known . The present invention utilizes the electrical output signals of the photodetectors 270 and 280 for precise wavelength measurement.

9, the transmission band 1110 of the specific channel filter when the incident angle is 0 is controlled by the signal processing unit 400 and the rotation plate 250 and the DWDM channel filter 230 and / or the CWDM channel filter 240 ). ≪ / RTI > In the example of FIG. 9, when the incident angle is rotated by dθ, the incident angle becomes dθ, and the transmission band of the channel filter can be changed to 1120. When it is further rotated by d? Again, the incident angle becomes 2d? And the transmission band of the channel filter becomes 1130. When the incident angle is continuously increased by the d &thetas;, the incident light is continuously increased, and accordingly the transmission band of the channel filter continues to move to the lower side and the incident angle becomes a x d &thetas; It gets caught in the corner. 9, since the optical wavelength 1100 is present within the transmission band of the filter until the rotation angle of the motor 260 or the filter is a × d? 1150, the output of the photodetectors 270 and 280 becomes a high value The light wavelength 1100 deviates from the filter transmission band and the filter can not be transmitted. As a result, the output of the photodetectors 270 and 280 hardly comes out. Since the optical wavelength 1100 does not exist in the channel filter transmission band even when the maximum rotation angle in one channel filter is shifted by dθ, the outputs of the photodetectors 270 and 280 are not output.

Therefore, the signal processing unit 400 determines the number of times the output of the photodetector 270 or 280 moves from the high point to the low point, and the precise wavelength of the input light wavelength 1100 using the previously calculated measurement data Can be measured. For example, when k = 21 of the measurement data for a specific optical signal, when the outputs of the photodetectors 270 and 280 are high and the rotation angle is increased by 0.5 degrees (d?), The photodetectors 270 and 280 Assuming that the output is the final peak when k = 30 and the lowest point when k = 31, the signal processing unit 400 determines that the value of λ _RE (i) at k = 30 and dλ _REj It is possible to measure that the optical wavelength included in the input optical signal is 1297-1.225 = 1295.775 nm. Here, the high and low points of the electric signal can be set to a high point when the predetermined value is larger than the predetermined value, and to a low point when the electric signal is smaller than the predetermined value.

10 is a view for explaining a method of measuring a wavelength of an input optical signal according to another embodiment of the present invention.

Referring to FIG. 10, the output of the photodetectors 270 and 280 is very low when the light wavelength included in the input optical signal is too far from the center wavelength of the original channel and the first incident angle is zero. In this case, the conventional method can not recognize the channel and can determine the error, but it is not known what actually happened to the optical wavelength. On the other hand, in the present invention, the transmission band 1210 of the specific channel filter when the incident angle is 0 can be varied by rotating the rotating plate 250 and the filter by the control of the signal processing unit 400. In the example of FIG. 10, when the incident angle is rotated by dθ, the incident angle becomes dθ, and the transmission band of the filter can be changed to 1220. When it is further rotated by d? Again, the incident angle becomes 2d? And the transmission band of the channel filter becomes 1230. When the incident angle is continuously increased by the d &thetas;, the incident light is continuously increased and accordingly the transmission band of the channel filter continues to move to the lower side, and the incident angle becomes b x d &thetas; It gets caught in the corner. As shown in FIG. 10, since the optical wavelength 1200 exists outside the transmission band of the filter until the rotation angle of the motor 260 or the filter is b x d? (1250), the output of the photodetector 425 is maintained at a low value The optical wavelength 1200 is within the filter transmission band and the filter is transmitted. As a result, the output of the photodetectors 270 and 280 A high value is obtained. Since the optical wavelength 1200 exists in the channel filter transmission band up to the maximum rotation angle in one filter after the continuous movement by dθ, the outputs of the photodetectors 270 and 280 are maintained at a high value.

Therefore, the signal processing unit 400 determines the number of the d? Moved until the outputs of the photodetectors 270 and 280 drop from the low point to the high point and the precise wavelength of the light wavelength 1200 inputted using the previously calculated measurement data Can be measured. For example, when k = 21 of the measurement data for a specific optical signal, when the outputs of the photodetectors 270 and 280 are low and the rotation angle is increased by 0.5 degrees (d?), Assuming _{that the} output has an initial peak when k = 30, the signal processing unit 400 determines that the value of? _LE (i) at k = 30 and d? _LEj It is possible to measure that the optical wavelength included in the input optical signal is 1283-1.225 = 1281.775 nm.

9, when the outputs of the photodetectors 270 and 280 change from a high point to a low point as in the example of FIG. 9, the signal processing unit 440 uses the following equation (4) , 280 changes from a low point to a high point, the following equation (5) can be applied to obtain the optical wavelength included in the input optical signal.

Where λ (i) is the wavelength measured in the i-th channel, λ _RE (i), λ _LE (i), dλ _REj and dλ _LEj will there be determined from the data for measurement of the previously calculated, where, i and j can be obtained based on the channel information and the rotation angle information at the time when the outputs of the photodetectors 270 and 280 change from a high point to a low point or from a low point to a high point.

The optical output of each channel is obtained by obtaining the output signals of the photodetectors 270 and 280 of FIG. 9 or 10 at an incident angle position and dividing by the Responsivity (R) values of the previously measured photodetectors 270 and 280 Can be calculated using Equation (6).

Where I (i) is the output value of the photodetector 270, 280 obtained at the incident angle position. In the present embodiment, the photodetectors 270 and 280 select the intermediate position of the section where the high signal is outputted, but the intermediate position can be averaged and applied.

Although the above description is based on the CWDM channel, the technique of the present invention is applicable to both the CWDM channel and the DWDM channel.

11 is a diagram illustrating an embodiment in which 100 GHz DWDM is applied to the C-band (1530 to 1565 nm, bandwidth: 35 nm).

The DWDM technique as well as the C-band shown in FIG. 11 can be applied to O-band, E-band, S-band, L-band, and U-band.

12 is a graph showing a relationship between an incident angle and a wavelength displacement of a DWDM filter having a center wavelength of 1570 nm and an effective refractive index (n _eff ) of 1.5764.

Referring to FIG. 12, when the incident angle is 10 degrees, the maximum wavelength displacement is 9.5 nm and the wavelength displacement per wavelength dλ / dφ is -1.18 nm / deg. Therefore, in order to obtain a wavelength resolution of 0.05 nm, .

When a 50 GHz DWDM channel filter 230 having a transmission bandwidth of about 0.3 nm is applied in the configuration of the optical unit 200 shown in FIGS. 4 to 5, each filter of the DWDM channel filter 230 has a transverse length L = 2.0 mm , Thickness t = 1 mm, and effective refractive index = 1.5764. If the beam diameter of the input optical signal is 0.3 mm, the offset of the input optical signal is X = 0.55 mm and the inclined angle of the input optical signal is 2 degrees, the incident angle range of one filter is φ = 0 to 10.1 degrees. The wavelength displacement d? = -0.38 to -13.89 nm can be obtained. Therefore, the number of DWDM channel filters for measuring the wavelength in the entire bandwidth of the C-band is limited to four, and in this embodiment, the filter of the DWDM channel filter 230, . Therefore, the transmission central wavelength of the measuring light wavelength and the optical output with respect to the C- band entire channel (total number = 3 7nm / 0.4nm = 88 pieces) each filter 7 of 6nm about 50GHz DWDM channel filter 230 detached pieces . Referring to FIG. 12, if the incident angle is 8 degrees, since the wavelength displacement per 1 degree is 1.53 nm, a motor having a minimum rotation angle (d?) Of 0.03 degrees can be applied in order to shift the filter transmission band at intervals of 0.02 nm. In addition, each filter of the DWDM channel filter 230 may be a filter having a transmission band narrower than 0.2 nm.

As described above, the signal processing unit 400 controls the motor 260 through the control unit 300 and controls the rotation angle of the rotary plate 250 according to the control of the motor 260, thereby calculating a precise value of the wavelength included in the incident optical signal .

Now, the configuration of the light input unit 100 will be described.

The optical unit 200 of the optical wavelength analyzer according to an embodiment of the present invention separately has an optical signal input for measuring a wavelength of a CWDM channel and an optical signal input for measuring a wavelength of a DWDM channel. Accordingly, the optical input unit 100 can transmit two optical signals to the optical unit 200 in correspondence with two inputs of the optical unit 200. Or only one of the two inputs. In this case, the optical unit 200 can measure only the wavelength of the CWDM channel or only the wavelength of the DWDM channel. That is, the optical input unit 100 transmits an optical signal to the two collimator lenses 210 and 220 of the optical unit 200.

13 is a diagram illustrating a configuration of a light input unit 100 according to an embodiment of the present invention.

13, the optical input unit 100 transmits the optical signals coming from the two optical input interfaces 110 and 111 to the collimating lenses 210 and 220, respectively. The optical wavelength channel analyzer implemented by the optical input unit 100 of FIG. 13 and the optical unit 200 of FIGS. 4 and 5 measures a DWDM channel signal when an external optical signal enters through the first optical input interface 110, Upon entering through the second optical input interface 111, the CWDM channel signal can be measured. 13, when a DWDM channel and a CWDM channel are combined in one optical signal, there is a disadvantage in that the wavelength of the DWDM channel and the wavelength of the CWDM channel included in the optical signal can not be simultaneously measured. However, And the CWDM channel can be measured.

14A and 14B are diagrams showing the configuration of a light input unit 100 according to another embodiment of the present invention.

FIG. 14A shows a case where a DWDM channel signal is input, and FIG. 14B shows a case where a CWDM channel signal is input.

14A and 14B, the optical input unit 100 has only one optical input interface 120 and an optical splitter 121 is provided in the optical input unit 100 to convert the input optical signal into two optical signals Signal, and transmits the signals to two collimating lenses 210 and 220, respectively. When a DWDM optical signal is input as shown in FIG. 14A, a DWDM signal is transmitted to the first collimating lens 210, and is finally incident on the DWDM wavelength measuring photodetector 270 shown in FIGS. 4 to 5 to obtain a DWDM wavelength And light intensity can be measured. At this time, the DWDM wavelength is included in the optical signal input to the second collimating lens 220, but the CWDM channel filter 240 is completely filtered and the DWDM wavelength does not appear in the photodetector 280 for CWDM measurement. When the CWDM optical signal is input as shown in FIG. 14B, the CWDM optical signal is finally input to the CWDM wavelength measuring photodetector 280 shown in FIGS. 4 to 5, and the wavelength and light intensity of the CWDM signal can be measured. The optical wavelength analyzer implemented by the optical input unit 100 of FIGS. 14A and 14B and the optical unit 200 of FIGS. 4 and 5 performs DWDM channel analysis or CWDM channel analysis, respectively, similar to the embodiment of FIG. And the optical intensity of the optical signal in which the DWDM and the CWDM channels are combined can not be measured. However, since the external optical signal is input using one optical input interface 130, it is convenient and easy to use There are advantages to be able to.

15A and 15B are diagrams showing a configuration of a light input unit 100 according to another embodiment of the present invention.

FIG. 15A shows a case where a DWDM channel signal and a CWDM channel signal are input through a combined optical line, and FIG. 15B shows a case where only a CWDM channel signal is input.

15A and 15B, the optical input unit 100 includes one optical input interface 130. Even when a DWDM channel and a CWDM channel are combined in an optical signal to be inputted, And the light intensity of each wavelength can be measured.

15A, when an external optical signal including a DWDM channel and a CWDM channel is input, the DWDM optical signal and the CWDM optical signal arrive at the DWDM filter module 132 through an optical splitter 131. The DWDM filter module 132 is designed to transmit optical signals of the DWDM wavelength band and reflect the other optical signals. The optical signals including the DWDM wavelengths of the optical signals pass through the DWDM filter module 132 And finally enters into a photodetector 270 for DWDM wavelength measurement. The optical signal including the CWDM wavelength is reflected by the DWDM filter module 132, reaches the optical switch 133, passes through the optical switch 133, and finally enters the CWDM wavelength measuring photodetector 280. At this time, the wavelength of the region 902 where the CWDM wavelength and the DWDM wavelength overlap may not be measured because the wavelength is not reflected by the DWDM filter module 132.

However, if a total of 18 CWDM channel optical signals are to be measured for the CWDM channel, as shown in FIG. 15B, the optical path inside the optical switch 133 is switched to receive the optical signal from the optical switch 131 as shown in FIG. 15B All of the 18 CWDM channel signals can finally be incident on the photodetector 280 for CWDM measurement.

16A and 16B are views showing the configuration of a light input unit 100 according to another embodiment of the present invention.

16A shows a case where a DWDM channel signal and a CWDM channel signal are input through a combined optical line, and FIG. 16B shows a case where only a CWDM channel signal is input.

16A and 16B show a case where an optical switch 141 is applied instead of the optical splitter 131 shown in Figs. 15A and 15B, and one embodiment shown in Figs. 16A and 16B is a case where the optical splitter 131 The optical signal intensity can be reduced.

Figs. 17A to 17D and Figs. 18A to 18D are diagrams showing the configuration of a light input unit 100 according to another embodiment of the present invention.

17A to 17D and 18A to 18D, the optical input unit 100 is provided with two optical input interfaces 150 and 151, and the optical signals traveling in both directions from one optical line It is configured to measure simultaneously.

17A to 17D, a DWDM optical signal 1741 traveling in the right direction and a DWDM optical signal 1741 traveling in the right direction and a DWDM optical signal 1743 traveling in the left direction and a CWDM optical signal 1744 17A shows a configuration of the optical input unit 100 for measuring the DWDM optical signal 1743 and the CWDM optical signal 1744 traveling in the left direction. FIG. 17B shows a configuration of the optical input unit 100, And a light input unit 100 for measuring a DWDM optical signal 1741 and a CWDM optical signal 1742. The optical signals are incident on the two collimating lenses 210 and 220 via the optical splitter 152 and the optical switch 153. The optical signals are propagated in the right direction Direction can be incident on the collimating lens, the wavelength of the bidirectional optical signal in which the DWDM signal and the CWDM signal are mixed can be sequentially measured. The DWDM filter module 154 and the optical switch 155 operate in the same manner as the DWDM filter module 132 and the optical switch 133 of FIG.

17C and 17D show the internal operation of the optical input unit for measuring only the CWDM optical signal. In order to measure only the CWDM optical signal, the right direction CWDM signal or the left direction CWDM signal may be transmitted to the collimator lens 220 by operating the optical switch 153 and the optical switch 155.

17A to 17D can be configured such that the optical signal input to the optical input interface 150 by the optical splitter 152 can be output to the optical input interface 151 and vice versa, Since the optical signal inputted into the optical line can be outputted to the optical input interface 150, the wavelength of the optical signal passing through the optical line can be measured while maintaining the communication state of the optical line.

18A to 18D, in order to measure an optical signal traveling in both directions in the optical line, Figs. 18A to 18D show a case where the optical splitter 152 is removed in Figs. 17A to 17D, As shown in FIG. 18A to 18D, there is an advantage that optical signals of greater magnitudes than those of FIGS. 17A to 17D are output because light intensity degradation due to the optical splitter 152 is alleviated, although the communication state of the optical line is not maintained unlike FIGS. 17A to 17D .

The optical wavelength channel analyzer according to the present invention applies the various optical input unit 100 configurations of FIGS. 13 to 18 as described above, and converts the optical signals input from the optical input unit 100 into CWDM channels and wavelengths of DWDM channels It is possible to analyze the intensity of the wavelength and the wavelength possessed by the optical signal.

In particular, it is possible to produce an optical wavelength channel analyzer that can be easily changed according to a user's demand or purpose by modularizing various types of optical input units 100 according to user settings.

In addition, the present invention provides a portable optical wavelength channel analyzer capable of simultaneously analyzing CWDM channels and DWDM channels that have not existed before, thereby enabling installation, maintenance, and repair work for a user's convenient optical line.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

Claims (13)

1. An optical wavelength analyzer for analyzing a wavelength included in an optical signal and intensity of each wavelength,

   A light input unit, an optical unit, a control unit, a signal processing unit, and a display unit,

   Wherein the optical input unit receives an optical signal including a plurality of optical wavelengths and transmits the optical signal to the optical unit through two optical signals,

   The optical unit filters two optical signals from the optical input unit by using two channel filters having different wavelength bands to be filtered attached to the rotating plate and outputs an electric signal proportional to the light intensity of the wavelength corresponding to each channel And outputs,

   The control unit controls the rotation angle of the rotation plate of the optical unit,

   Wherein the signal processing unit generates a rotation angle control signal for the control unit, extracts an optical intensity value for each wavelength based on the rotation angle and the electrical signal,

   Wherein the display unit displays the light intensity value for each wavelength extracted from the signal processing unit,

   Optical wavelength analyzer.
2. The optical system according to claim 1,

   A first lens and a second lens that convert the two optical signals from the optical input unit into parallel light;

   A first channel filter for filtering the first parallel light coming from the first lens;

   A second channel filter for filtering the second parallel light coming from the second lens;

   A rotating plate to which the first channel filter and the second channel filter are attached;

   A motor for rotating the rotating plate;

   A first photodetector for converting parallel light having passed through the first channel filter into a first electrical signal and outputting the first electrical signal; And

   A second photodetector for converting parallel light having passed through the second channel filter into a second electrical signal and outputting the second electrical signal;

   / RTI >

   Optical wavelength analyzer.
3. 3. The method of claim 2,

   Wherein the first channel filter is attached parallel to a tangent of the rotating direction of the rotating plate so that the angle at which the first parallel light enters the first channel filter changes according to the rotation of the rotating plate, Wherein the angle of incidence of the second parallel light to the second channel filter is not changed according to the rotation of the rotation plate,

   Optical wavelength analyzer.
4. The method of claim 3,

   Wherein the first channel filter is a CWDM channel filter for filtering a CWDM channel,

   Wherein the second channel filter is a DWDM channel filter for filtering at least one of a C-band, a 0-band, an E-band, an S-band, an L-band, a U-

   Optical wavelength analyzer.
5. 3. The method of claim 2,

   Wherein the first channel filter and the second channel filter are attached parallel to a tangent of the rotating direction of the rotating plate so that an angle at which the first parallel light enters the first channel filter in accordance with rotation of the rotating plate, Wherein an angle at which the parallel light enters the second channel filter changes,

   Optical wavelength analyzer.
6. 6. The method of claim 5,

   Wherein the first channel filter and the second channel filter comprise:

   Filtering different wavelength bands,

   Each of which filters for at least one of a CWDM channel, a C-band, a 0-band, an E-band, an S-band, an L-band, a U-

   Optical wavelength analyzer.
7. 3. The method of claim 2,

   The first channel filter may be classified into one or more groups,

   Each group is composed of a plurality of filters having the same filtering bandwidth, and the transmission bandwidth is different between the groups, or the wavelength band to be filtered is different,

   Optical wavelength analyzer.
8. 3. The method of claim 2,

   Wherein the first channel filter is composed of seven C-band filters, the filtered center wavelength of each of the seven filters is between 1530 nm and 1565 nm, and the interval between the filtered central wavelengths of each filter is 6 nm.

   Optical wavelength analyzer.
9. 3. The method of claim 2,

   The second channel filter may be classified into one or more groups,

   Each group is composed of a plurality of filters having the same bandwidth, and the groups have different transmission bandwidths or different wavelength bands,

   Optical wavelength analyzer.
10. 3. The method of claim 2,

    Wherein the second channel filter is composed of 18 filters, the filtered center wavelengths of the respective filters of the 18 filters are between 1270 nm and 1610 nm, and the interval between the filtered central wavelengths of the respective filters is 20 nm,

    Optical wavelength analyzer.
11. The method according to claim 3 or 5,

    The signal processing unit,

    The rotation angle at a point where the electric signal changes from a high point higher than a preset reference value to a low point that is lower than a predetermined reference value or a point where the electric signal changes from a low point lower than the preset reference value to a high point higher than the predetermined reference value And extracting a wavelength value included in the optical signal,

    Optical wavelength analyzer.
12. 3. The apparatus according to claim 2,

    One optical input interface for receiving the optical signal; And

    And an optical splitter for splitting the optical signal received through the optical input interface into two optical signals,

    And the two optical signals output from the optical splitter are respectively incident on the first lens and the second lens,

     Optical wavelength analyzer.
13. 3. The apparatus according to claim 2,

    One optical input interface for receiving the optical signal;

    An optical splitter for splitting the optical signal received through the optical input interface into two optical signals;

    A filter module passing only the wavelength band of the first channel filter and reflecting the wavelength band of the second channel filter; And

    And an optical switch for receiving and outputting any one of an optical signal reflected from the filter module and an optical signal coming from the optical splitter,

    An output of the filter module is transmitted to the first lens, and an output of the optical switch is transmitted to the second lens.

    Optical wavelength analyzer.

Images