WO2006008786A1 - Wavelength-variable optical transmitter/receiver apparatus - Google Patents

Abstract

First photoelectric converting means (10a) converts an optical input signal (31) from a client side to a first electric signal (32). Digital pattern generating means (14) generates a pseudo random number pattern signal (33) representative of wavelength information. Electric signal superimposing means (16) superimposes the pattern signal (33) on the first electric signal (32) to produce a superimposed electric signal (34). First electrooptic converting means (11b) converts the signal (34) to a particular optical output signal (35). On the other hand, optical filter means (12) selects an optical signal (42) having a particular wavelength from an input wavelength-multiplexed light (41). Second photoelectric converting means (10b) converts the optical input signal (42) selected by the optical filter means (12) to a second electric signal (43). Digital pattern detecting means (15) detects a pattern signal (44) superimposed on the second electric signal (43). Second electrooptic converting means (11a) converts the second electric signal (43) to an optical output signal (45).

Description

 Specification

 Tunable optical transceiver

 Technical field

 [0001] The present invention inputs an optical input signal from the client side, converts this optical input signal into an optical output signal having a wavelength used on the wavelength multiplexing section side, and transmits the optical output signal. This relates to a wavelength tunable optical transmitter / receiver that selects an optical signal of a specific wavelength from the wavelength multiplexed light and sends it as an optical output signal to the client side. The present invention relates to a wavelength tunable optical transmitter / receiver configured so as not to perform analysis processing.

 Background art

 [0002] In an optical transmission / reception apparatus used in an optical transmission system that switches a transmission path or a communicating opposite station according to a wavelength (wavelength path switching), a wavelength variable light source or a wavelength tunable transmitter for changing a transmission wavelength, Alternatively, it has a tunable optical filter for switching the reception wavelength. In such an optical transmitter / receiver, in order to correctly set the wavelength tunable optical filter arranged on the receiving side to a desired wavelength (channel), the optical signal after passing through the filter is usually observed and set based on this. For example, based on the wavelength information carried in the overhead of the frame of the transmission signal, it is generally performed to determine whether or not the wavelength that has passed through the filter is a desired wavelength. (For example, see Patent Document 1).

 [0003] Also, a plurality of transmission speeds are mixed, and a plurality of signal types (for example, SDH (Synchronous Digital Hierarchy) thread or IP (Internet

It is difficult to detect and analyze the end of a signal input to an optical transceiver because it is difficult to expect a specific transmission frame in an optical transceiver that is applied to a system in which a protocol system is mixed). That is, it is difficult to obtain wavelength information from the frame. In this way, when the wavelength information in the frame overhead cannot be obtained during the opto-electric conversion and electro-optical conversion between the client side and the wavelength multiplexing section side, the frequency corresponding to the wavelength or channel number is set. Each transmitted optical signal is modulated at a low frequency, and its frequency is received at the receiving end. It is possible to determine the transmitted channel number by identifying the component (see, for example, Patent Document 2 and Patent Document 3).

[0004] Patent Document 1: Japanese Patent Laid-Open No. 9-51325

 Patent Document 2: JP-A-9-51324

 Patent Document 3: Japanese Patent Laid-Open No. 11-41208

 Disclosure of the invention

 Problems to be solved by the invention

[0005] A tunable optical transmitter / receiver that is applied to a system in which a plurality of transmission speeds and transmission signal types coexist, and does not identify and reproduce input signal data, and does not perform termination / analysis processing of signal data In order to transmit the wavelength information to the wavelength multiplexing section side and to accurately control the variable optical filter based on this information, it is possible to apply low frequency modulation corresponding to the wavelength to the transmitted optical signal. . However, in future ultra-high-density wavelength multiplexing systems that exceed 100 wavelengths, it is difficult to define wavelength information such as natural frequencies for each wavelength, and different types of low-frequency oscillators are prepared. Therefore, there is a problem that the cost of parts increases. Since the wavelength tunable optical transmitter / receiver configured as described above cannot determine the signal quality by itself and operates on the premise that an optical signal is supplied from the outside, all devices such as when the system is started up. There is a problem that it is not possible to perform performance evaluation and operation check of the wavelength tunable optical transceiver in a state where is not connected.

 [0006] The present invention has been made in view of the above, and in a wavelength tunable optical transceiver that does not identify and reproduce input signal data and does not perform termination processing of signal data. Thus, a wavelength tunable optical transmitter / receiver capable of superimposing wavelength information on an optical signal easily and inexpensively even when the frequency increases.

 Means for solving the problem

In order to solve the above-described problems and achieve the object, the wavelength tunable optical transceiver according to the present invention inputs an optical input signal from the client side and uses an optical output signal having a wavelength used on the wavelength multiplexing section side. The optical signal of a specific wavelength is selected from the wavelength multiplexed light input from the wavelength multiplexing section side, and this is transmitted to the client side as an optical output signal In the wavelength tunable optical transceiver, the first photoelectric conversion means for converting the optical input signal from the client side to the first electrical signal, the digital pattern generation means for generating the pseudo random pattern signal expressing the wavelength information, the first (1) An electric signal superimposing means for superimposing an electric signal by superimposing a pseudo random number pattern signal on the electric signal, a first electric light converting means for converting the superimposed electric signal into a predetermined optical output signal, and an input from the wavelength multiplexing section side Optical filter means for selecting an optical signal of a specific wavelength from among the wavelength multiplexed light to be transmitted, a second photoelectric conversion means for converting the optical input signal selected by the optical filter means into a second electrical signal, and a second electrical signal The digital pattern detecting means for detecting the superimposed pseudorandom pattern signal and the second electro-optical converting means for converting the second electric signal into an optical output signal Ming effect

 [0008] In the wavelength tunable optical transceiver according to the present invention, the first photoelectric conversion means converts the optical input signal from the client side into the first electrical signal, and the digital pattern generation means expresses the wavelength information. A random number pattern signal is generated, and the electrical signal superimposing unit superimposes the pseudo random number pattern signal on the first electrical signal to form a superimposed electrical signal, and the first electro-optical conversion unit converts the superimposed electrical signal into a predetermined optical output signal . On the other hand, the optical filter means selects an optical signal of a specific wavelength from the wavelength multiplexed light input from the wavelength multiplexing section side, and the second photoelectric conversion means converts the optical input signal selected by the optical filter means to the second electrical signal. Since the digital pattern detection means detects the pseudo random pattern signal superimposed on the second electric signal, and the second electric light conversion means converts the second electric signal into an optical output signal, Even when the number of multiplexing is increased, it is possible to easily and inexpensively overlap the wavelength information with the optical signal.

 Brief Description of Drawings

 FIG. 1 is a configuration diagram of a wavelength tunable optical transceiver according to a first embodiment.

 FIG. 2 is a configuration diagram showing a modification of the first embodiment in which third photoelectric conversion means for photoelectrically converting the band of the pseudo random number pattern signal is provided.

FIG. 3 is a configuration diagram showing a modification of the first embodiment in which a scramble function is provided on the digital pattern generation means side and a descrambling function is provided on the digital pattern signal detection means side. It is.

 FIG. 4 is a configuration diagram of a wavelength tunable optical transceiver according to the second embodiment.

 FIG. 5 is a table showing conditions and symptoms of various abnormal states that can be separated in the second embodiment.

 Explanation of symbols

[0010] 10a photoelectric converter (first photoelectric conversion means)

 10b Photoelectric converter (second photoelectric conversion means)

 10c photoelectric converter (third photoelectric converter)

 11a Electro-optical converter (second electro-optical conversion means)

 l ib electro-optic converter (first electro-optic conversion means)

 12 Variable optical filter (optical filter means)

 13 Processor (control means)

 14 Digital pattern generator (digital pattern generator)

 15 Digital pattern detector (Digital pattern detection means)

 16 Superimposer (electric signal superimposing means)

 17a First optical power monitoring means

 17b Second optical power monitoring means

 21 Scramble means

 22 Descramble means

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a wavelength tunable optical transceiver according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

 [0012] Embodiment 1.

FIG. 1 is a configuration diagram of the wavelength tunable optical transceiver according to the first embodiment. The wavelength tunable optical transmission / reception device 101 is provided between a client device (not shown) and the wavelength multiplexing side optical communication network. The wavelength tunable optical transceiver 101 includes the client side optical input port IP1 and client side optical output port OP2 connected to the client device, and the wavelength division multiplexing side optical output port 0P 1 connected to the wavelength multiplexing side optical communication network. And wavelength multiplexing section side optical input port I have IP2. Then, the wavelength tunable optical transceiver 101 receives the optical input signal 31 from the client side, converts it to an optical output signal 35 of the wavelength used on the wavelength multiplexing section side, and transmits it. A portion that performs this operation is a transmission unit. Also, the wavelength tunable optical transceiver 101 selects an optical signal 42 of a specific wavelength from the wavelength multiplexed light 41 input from the wavelength multiplexing section side, and sends this as an optical output signal 45 to the client side. The part that performs this operation is the receiver.

 In FIG. 1, an alternate long and short dash line indicates a path of an optical signal, a dotted line indicates a path of a control signal, and a solid line indicates a path of an electrical signal other than the control signal. The wavelength tunable optical transmitter / receiver 101 first has a processor 13 which is a control means for controlling the variable filter 12 and controlling the operation of the entire apparatus.

 [0014] Further, the wavelength tunable optical transceiver 101 includes, in the transmission unit, a photoelectric converter 10a that is a first photoelectric converter, a digital pattern generator 14 that is a digital pattern generator, and an electric signal superimposing unit. And the electro-optic converter l ib as the first electro-optic conversion means. The photoelectric converter 10a is connected to the client-side optical input port IP1, and converts the optical input signal 31 input from the port into a first electrical signal (main signal) 32. The digital pattern generator 14 generates a pseudo-random pattern signal (digital random number pattern signal) 33 in which wavelength information is expressed. The superimposer 16 superimposes the pseudo random number pattern signal 33 on the first electric signal (main signal) 32 to obtain the superimposed electric signal 34. The electro-optic converter l ib converts the superimposed electrical signal 34 into an optical output signal 35 having a predetermined wavelength, and outputs it from the wavelength multiplexing section side optical output port OP1.

[0015] In addition, the wavelength tunable optical transceiver 101 includes a variable filter 12 as an optical filter means, a photoelectric converter 10b as a second photoelectric conversion means, and a digital pattern as a digital pattern detection means in the receiving unit. It has a detector 15 and an electro-optical converter 11a which is a second electro-optical converting means. The variable filter 12 is connected to the wavelength division multiplexing side optical input port IP2 and selects the optical input signal 42 having a specific wavelength from the wavelength division multiplexed light 41 inputted from the wavelength division multiplexing side. The photoelectric converter 10 b converts the optical input signal 42 selected by the variable filter 12 into a second electrical signal 43. The digital pattern detector 15 detects the pseudo random number pattern signal 44 superimposed on the second electric signal 43 to obtain wavelength information. Electro-optic converter 11a converts the second electrical signal 43 into an optical output signal 45 and outputs it from the client side optical output port OP2. The processor 13 controls the optical input signal 42 selected by the variable filter 12 based on the wavelength information extracted by the digital pattern detector 15.

 Next, the operation will be described. The wavelength tunable optical transceiver 101 receives the optical input signal 31 from the client side, converts it to the optical output signal 35 of the wavelength used on the wavelength multiplexing section side, transmits it, and transmits the wavelength input from the wavelength multiplexing section side. An optical input signal 42 having a specific wavelength is selected from the multiplexed light 41 and is transmitted as an optical output signal 45 to the client side. Here, in the present embodiment, since the operation is performed regardless of the transmission speed and protocol of the main signal to be transferred, various processes and analyzes regarding data or related frames are not performed at the stage of the electrical signal. Then, only the wavelength conversion by the conversion from the optical signal to the electric signal and the conversion from the electric signal to the optical signal is performed.

 In the present embodiment, a pseudo random pattern signal 33 having a low transmission rate corresponding to each wavelength is supplied to the digital pattern generator 14 as a signal corresponding to the optical output signal 35 to the wavelength multiplexing section side. This is superimposed on the first electrical signal (main signal) 32 and sent to the wavelength multiplexing section side by the photoelectric converter l ib. On the other hand, the receiving unit extracts the pseudo random number pattern signal 44 from the wavelength multiplexed light 41 input from the wavelength multiplexing section side, and sets the center wavelength of the variable optical filter 12 to the correct wavelength based on the extraction result.

 Here, the method of controlling the variable optical filter 12 can be set to a desired wavelength by performing the following method. First, the entire bandwidth of the used wavelength is scanned, and scanning is stopped at a wavelength setting that provides desired wavelength information. Next, the filter wavelength setting is finely adjusted so that the filter output power (or the received light power of the photoelectric converter 10b) becomes maximum. At that time, as a monitor of the filter output power or received light power, the digital pattern detector 15 that extracts the wavelength information, and the peak detection output of the low-speed signal corresponding to the signal speed of the pseudorandom pattern signal corresponding to the wavelength information. By providing a monitor or an intensity monitor of the frequency component peculiar to the pseudorandom pattern signal, it is possible to finely control the variable optical filter 12 with higher accuracy.

As a pseudo-random pattern signal used as wavelength information, as a method that can be easily realized by hardware, for example, a pseudo-random sequence (PRBS: Pseudo-random

Bit Sequence) may be used (examples below equation 2 ⁷ - a signal generator polynomial PRBS7 having 1 periodicity).

[0020] x '+ x' + x ⁰

[0021] When the above PRBS7 sequence is used, since 7 consecutive patterns other than 0 can be generated, 2 ⁷ — 1 type (127 patterns) can be easily generated. By assigning a wavelength to this pattern, it is possible to easily generate and assign a large number of wavelength information or channel numbers. Here, in order to use the periodic pattern shown in the above example as a plurality of patterns, it is necessary to separately insert a pattern delimiter identification bit sequence indicating the beginning or end of the pattern (in the above example, In principle, it is not used, and 7 consecutive 0 patterns can be used as a delimiter). For example, in the above example, only the first 7 bits of the pattern or 7 bits after a specific delay time from the pattern delimiter may be identified as the pattern identification, or the order of the data arrangement of all patterns may be identified. You may do it. That is, wavelength information may be included in either the start bit sequence of the pseudo random number pattern signal or the bit string at a specific time position to identify this.

 As described above, since the bit sequence for pattern delimitation identification is added to at least one of the front and rear of the pseudo random number pattern signal according to the present embodiment, periodic patterns are used as a plurality of patterns. can do. Also, the wavelength information is expressed by either the start bit sequence of the pseudo random number pattern signal or the bit string at the specific time position, and by identifying this, whether the wavelength that passed through the filter is the desired wavelength The power of failure can be determined.

 [0023] In addition, wavelength information can be assigned to the repetitive period length of the pseudorandom pattern signal or the number of PRBS stages), and the wavelength information can be extracted at high speed by not using the pattern delimiter bit sequence. Is possible.

 [0024] It should be noted that as the pseudo-random pattern signal, it is possible to use a series other than the above, which can easily generate a series and can easily generate a reference pattern by pattern extraction on the receiving side. Needless to say.

[0025] Although not shown in FIG. 1, the digital pattern detector 15 is connected to the second electric signal (main signal) 43. Low-speed signal electrical filter (electric filter means) for extracting pseudo-random pattern signal 44 corresponding to wavelength information, low-speed signal discriminator (identification means) for A / D conversion, and pattern identification And an arithmetic processing unit. The electric filter has a pass band corresponding to the transmission signal speed of the pseudo random number pattern signal. The arithmetic processing performed by the arithmetic processing unit extracts, for example, a pseudo-random pattern signal 44 by comparing a plurality of reference data sequences with the received pattern sequence (for example, XOR operation (exclusive OR operation) between each bit). In other words, the pseudo random pattern signal 44 is the one that produces a result of 〃0 "for all the comparison bits).

 In the present embodiment, the configuration shown in FIG. 2 may be used in which a signal branched from the subsequent stage of the photoelectric converter 10 b is used as the input of the digital pattern detector 15. That is, in the wavelength tunable optical transceiver 102 shown in FIG. 2, the photoelectric converter 10c as the third photoelectric conversion means is connected to the optical line branched from the variable optical filter 12, and the photoelectric converter 10c converts the band (low-speed band) component occupied by the pseudo random number pattern signal superimposed on the optical input signal 42 selected by the variable optical filter 12 into the third electric signal. Then, the digital pattern detector 15 detects the pseudo random number pattern signal superimposed on the third electric signal. At this time, the photoelectric converter 10b converts the band of the second electric signal (main signal) 43 in the optical input signal 42 into an electric signal. In this way, the photoelectric converter 10c that branches the optical input signal 42 from the preceding stage of the photoelectric converter 10b and photoelectrically converts only the band necessary for detection of the pseudorandom pattern signal is referred to as the photoelectric converter 10b. May be provided separately.

 [0027] In the present embodiment, the digital pattern detector 15 and the digital pattern generator 14 are configured separately from the processor 13, but in these devices, the basic processing is digital signal processing. Therefore, the digital pattern detector 15 and the digital pattern generator 14 can be configured as a part of the processor 13.

[0028] Further, in the case where the electro-optic converter l ib according to the present embodiment is a wavelength tunable device such as a fixed wavelength device or a tunable device, the processor 13 controls the oscillation wavelength. It is also possible to do this. In this embodiment, the optical filter means is a variable optical filter 12 that can change the filter center wavelength, and the variable S is an optical filter. Ruta bandwidth may also be used. Further, the present invention can be applied as a means for transmitting wavelength information in an optical transmission / reception apparatus even if the optical filter is a fixed wavelength filter.

 [0029] As described above, according to the wavelength tunable optical transceiver 101 of the present embodiment, wavelength information is represented by a low-speed pseudorandom pattern signal that can be easily generated by a digital circuit, and the wavelength multiplexing section side from the transmission end. To send. Therefore, even if the number of wavelength multiplexing increases, it is possible to generate a pattern corresponding to multiple wavelengths at a low cost, and it is provided in the wavelength tunable optical transceiver by analyzing the pseudorandom pattern signal extracted at the receiving end. In addition, it is possible to check whether the wavelength tunable device (tunable optical filter 12) is operating at an appropriate wavelength, and to evaluate the performance of the device using a low-speed pseudorandom pattern signal even when there is no external input optical signal. Operation check can be performed. In other words, a wavelength information transmission method that can handle a large number of wavelengths easily and at low cost in a type of wavelength tunable optical transmitter / receiver that does not identify and reproduce input signal data and does not perform termination / analysis processing of signal data. When using a tunable filter as an optical filter, the wavelength can be set accurately.

 In addition, the wavelength tunable optical transceiver 101 according to the present embodiment uses the pseudo random number pattern signal 33 to the wavelength multiplexing section side without using an input optical signal from the client side. Since the modulated optical signal transmission and the identification of the modulated optical signal can be realized, if the start-up work such as the optical level adjustment at the wavelength multiplexing section side that occurs at the time of system introduction or the like can be easily performed, the effect is achieved.

[0031] It should be noted that in the tunable optical transceiver 101 of the present embodiment, the signal speed of the pseudorandom pattern signal 33 representing the wavelength information is lower than that of the first electrical signal (main signal) 32, and the first power The pseudo random number pattern signal 33 is the first electrical signal (main signal) 3 because it is outside the occupied band of the air signal (main signal) 32 (not shown here, outside the operating band of the optical transmission / reception device on the client side) 3 It is a thing that does not affect 2. However, when more information is represented by the pseudo-random pattern signal 33 and superimposed on the main signal with a higher-speed digital pattern (for example, approximately the same speed as the main signal transmission rate), This can be realized with the configuration shown in Fig. 3. In FIG. 3, the tunable optical transmitter / receiver 103 is provided with a scramble means 21 as an electric signal superimposing means, while a digital pattern signal detecting means is a descramble means 22. The scramble means 21 scrambles the first random signal (main signal) 32 with the pseudo random pattern signal 33 to obtain a superimposed electric signal 34. On the other hand, the descrambling means 22 detects the pseudorandom pattern signal 44 scrambled to the second electric signal 43 by descrambling the second electric signal 43 to obtain wavelength information. As described above, the digital pattern generation means side has a scramble function, and the digital pattern signal detection means side has a descrambling function, so that the first electric signal ( Wavelength information can be transmitted without adversely affecting the main signal.

 [0033] Embodiment 2.

 FIG. 4 is a configuration diagram of the wavelength tunable optical transceiver according to the second embodiment. In FIG. 4, in the variable wavelength optical transceiver 104, the first optical power monitoring means 17a is provided before the variable optical filter 12, and the second optical power monitoring means 17b is provided after the variable optical filter 12. It is. The optical power monitoring means 17a and 17b are connected to the processor 13 by signal lines (not shown). Other configurations are the same as those in the first embodiment.

 [0034] The operation will be described. In this embodiment, compared with the first embodiment, by adding the optical power monitoring means 17a and 17b, it becomes possible to isolate an abnormal operation state peculiar to the optical transceiver. The optical power monitoring means 17a, 17b can be composed of, for example, a photoelectric converter and an electric amplifier.

 [0035] In Embodiment 1 described above, it was possible to identify whether or not the wavelength was correctly selected. However, abnormal states such as abnormal control of the variable optical filter 12 and deterioration of transmission quality itself were observed. When this occurs, there is a problem that it is not possible to determine whether the cause is due to the control of the variable optical filter 12 or other factors. In the present embodiment, by increasing the number of locations where the state of the wavelength multiplexed light 41 can be monitored, when an abnormality occurs on the receiving side, the cause can be identified in detail.

FIG. 5 is a diagram showing, in a tabular form, an example in which various types of abnormality causes are separated according to the present embodiment. By monitoring the power of wavelength-division multiplexed light 41, various abnormal conditions can occur in addition to normal operation. This makes it possible to clearly define the system's abnormal behavior as well as to perform abnormal processing based on this.

 In FIG. 5, first, based on the output results of the two optical power monitoring means 17a and 17b, whether the wavelength multiplexed light 41 on the wavelength multiplexing section side input to the variable optical filter 12 is in a disconnected state or variable light. It is possible to determine whether there is an error in the setting of the filter 12 and the output power of the variable optical filter 12 is cut off. In addition, as an abnormal operation state, even when a predetermined optical power is obtained at the output of the variable optical filter 12, if the variable optical filter 12 selects the wrong channel or the transmission quality itself deteriorates. However, it is assumed that the wavelength information cannot be extracted. However, with the configuration of the present embodiment, for example, the bit sequence for pattern delimitation identification cannot be detected, or the mark rate of the detected random number pattern Γ Τ And the probability of occurrence of 〃1 ") can be detected by detecting that the transmission quality has deteriorated from about 1/2, and finally it is shown in Fig. 5. The four types of status can be separated, and the card operating status can be accurately determined.

 That is, in this embodiment, at least one of the preceding stage and the succeeding stage of the variable optical filter 12 has an optical power monitoring means, and the monitoring result of this optical power monitoring means, the digital pattern detection Of the wavelength-division multiplexed light 41 as an optical input signal based on either the pseudo-random pattern signal 44 (wavelength information) extracted by the detector 15, the mark rate of the pseudo-random pattern signal 44, or the abnormal detection result of the pattern segment identification bit sequence The state is determined. In addition, the digital pattern signal detector 15 detects this as an error when the mark ratio of the pseudorandom pattern signal 44 deviates from about 1/2 or when the pattern delimiter identification bit sequence cannot be detected. .

 As described above, the wavelength tunable optical transceiver 104 of this embodiment is a type of wavelength tunable optical transceiver that does not identify and reproduce input signal data and does not perform termination processing of signal data. Nevertheless, the workability and operability of the system can be greatly improved, and it can be provided as a wavelength tunable optical transmitter / receiver having sufficient functions for actual operation.

 Industrial applicability

As described above, the wavelength tunable optical transmitter / receiver according to the present invention recognizes input signal data again. It is useful when applied to a wavelength tunable optical transmitter / receiver that does not generate signal termination and does not perform analysis processing, especially the wavelength of future ultra-high-density wavelengths multiplexing systems exceeding 100 wavelengths. The present invention is useful when applied to a variable optical transceiver.

Claims

The scope of the claims  [1] An optical input signal from the client side is input, converted into an optical output signal of the wavelength used on the wavelength multiplexing section side, and sent, and the wavelength-multiplexed light input from the wavelength multiplexing section side is a specific wavelength The optical signal is sent to the variable wavelength optical transmitter / receiver that sends it as an optical output signal to the client side.  A first photoelectric conversion means for converting an optical input signal from the client side into a first electrical signal; a digital pattern generation means for generating a pseudo-random pattern signal representing wavelength information;  An electric signal superimposing means for superimposing the pseudo random number pattern signal on the first electric signal to obtain a superimposed electric signal;  A first electro-optical conversion means for converting the superimposed electric signal into a predetermined optical output signal; an optical filter means for selecting an optical signal having a specific wavelength from the wavelength multiplexed light input from the wavelength multiplexing section side;  Second photoelectric conversion means for converting the optical input signal selected by the optical filter means into a second electrical signal;  A digital pattern detecting means for detecting a pseudo random number pattern signal superimposed on the second electrical signal;  A wavelength tunable optical transmission / reception apparatus comprising: a second electro-optical conversion unit that converts the second electric signal into an optical output signal. [2] An optical input signal from the client side is input, converted into an optical output signal of the wavelength used on the wavelength multiplexing section side, and sent, and the wavelength multiplexed light input from the wavelength multiplexing section side is a specific wavelength The optical signal is sent to the variable wavelength optical transmitter / receiver that sends it as an optical output signal to the client side. A first photoelectric conversion means for converting an optical input signal from the client side into a first electrical signal; a digital pattern generation means for generating a pseudo-random pattern signal representing wavelength information; An electric signal superimposing means for superimposing the pseudo random number pattern signal on the first electric signal to obtain a superimposed electric signal;  A first electro-optical conversion means for converting the superimposed electric signal into a predetermined optical output signal; an optical filter means for selecting an optical signal having a specific wavelength from the wavelength multiplexed light input from the wavelength multiplexing section side;  Second photoelectric conversion means for converting the optical input signal selected by the optical filter means into a second electrical signal;  Third photoelectric conversion means for converting a band occupied by a pseudo-random pattern signal superimposed on the optical input signal selected by the optical filter means into a third electrical signal;  Digital pattern detection means for detecting a pseudorandom pattern signal superimposed on the third electrical signal;  A wavelength tunable optical transmission / reception apparatus comprising: a second electro-optical conversion unit that converts the second electric signal into an optical output signal. 3. The wavelength tunable optical transmitter / receiver according to claim 1 or 2, further comprising a scramble function on the digital pattern generation means side and a descrambling function on the digital pattern signal detection means side. 4. The wavelength tunable optical transmission / reception according to claim 1, wherein the wavelength information is represented in either a start bit sequence of the pseudo random number pattern signal or a bit string at a specific time position. apparatus. 5. The tunable optical transmitter / receiver according to claim 1 or 2, wherein a pattern delimiter identification bit sequence is added to at least one of the front and rear of the pseudo-random pattern signal. [6] The transmission rate of the pseudo-random pattern signal generated by the digital pattern generation means is a low-speed signal rate that is outside the occupied band of the main signal transmission rate on the wavelength multiplexing section side. Item 3. The wavelength tunable optical transceiver according to item 1 or 2. [7] The digital pattern signal detecting means has a pseudo random pattern mark ratio of approximately 1 2. The method according to claim 1, wherein an error occurs in at least one of a case where the pattern delimiter identification bit sequence cannot be detected and a case where the pattern delimiter identification bit sequence cannot be detected. 2 is a wavelength tunable optical transmitter / receiver described in 2. [8] At least one of the preceding stage and the succeeding stage of the optical filter means has optical power monitoring means, and the state of the wavelength multiplexed light is determined based on the monitoring result of the optical power monitoring means. The wavelength tunable optical transceiver according to claim 1 or 2. [9] Optical power monitoring means are provided upstream and downstream of the optical filter means, the monitoring results of the two optical power monitoring means, the pseudo random number pattern signal extracted by the digital pattern detection means, 2. The state of the wavelength multiplexed light is determined based on at least one of a mark rate of a pseudorandom pattern signal and an abnormality detection result of the pattern delimiter identification bit sequence. 2. The wavelength tunable optical transmitter / receiver described in 2.  [10] The digital pattern detection means includes an electric filter means for low-speed signals having a pass band corresponding to the transmission signal speed of the pseudorandom pattern signal and an identification means for low-speed signals. The wavelength tunable optical transceiver according to claim 1 or 2.  11. The tunable optical transceiver according to claim 1, wherein the optical filter means has a wavelength band pass characteristic for a specific wavelength, and a center wavelength of the pass wavelength band is variable.  12. The wavelength tunable optical transceiver according to claim 1, wherein the optical filter means has a wavelength band pass characteristic with respect to a specific wavelength, and a bandwidth of the pass wavelength band is variable.