CN112038879B

CN112038879B - Cross-locked wavelength-adjustable high-speed laser and method

Info

Publication number: CN112038879B
Application number: CN202010770134.7A
Authority: CN
Inventors: 刘新峰; 强亮
Original assignee: Fiberhome Telecommunication Technologies Co Ltd
Current assignee: Fiberhome Telecommunication Technologies Co Ltd
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2022-04-19
Anticipated expiration: 2040-08-04
Also published as: CN112038879A

Abstract

The invention relates to the technical field of wavelength division multiplexing passive optical networks, and provides a cross-locked wavelength-tunable high-speed laser and a method thereof. The method comprises the steps that a first FP laser and a second FP laser are used for realizing the coupling of comb wave signals emitted by the first FP laser and the second FP laser through a coupling optical path structure; a filter is further arranged on a coupling optical path between the first FP laser and the coupling optical path structure so as to filter out a longitudinal mode with a specified wavelength in the first FP laser and enter the coupling optical path structure; the first FP laser and/or the second FP laser are/is further used for obtaining a regulation signal so as to adjust the corresponding appointed-level longitudinal modes of the first comb wave emitted by the first FP laser and the second comb wave emitted by the second FP laser to complete wavelength matching, and therefore cross locking of the target output wavelength is completed. The invention solves the problem of high-speed modulation by using the fact that the high-speed performance of the second FP laser is better when the second FP laser is in a wavelength locking state.

Description

Cross-locked wavelength-adjustable high-speed laser and method

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of wavelength division multiplexing passive optical networks, in particular to a cross-locked wavelength-tunable high-speed laser and a method thereof.

[ background of the invention ]

A Passive Optical Network (PON) technology is a point-to-multipoint Optical fiber access technology, and is composed of an Optical Line Terminal (OLT) on a central office side, an Optical Node (ONU) on a user side, and an Optical Distribution Network (ODN). A Time Division Multiplexing passive optical network (TDM-PON, abbreviated as "TDM-PON") system uses a broadcast technology for downlink data streams and a TDM technology for uplink data streams, so as to solve the problem of Multiplexing signals in each direction of multiple users. Wavelength Division Multiplexing passive optical network (Wavelength Division Multiplexing, abbreviated as WDM PON) based on Wavelength Division Multiplexing technology adopts Wavelength as the identification of an ONU at a user end, and realizes uplink access by using the Wavelength Division Multiplexing technology, which can provide a wider operating bandwidth. Meanwhile, the technical problems of ranging, fast bit synchronization and the like of the ONU in the time division multiple access technology can be avoided, and the exclusive wavelength has obvious advantages in time delay and jitter indexes.

In a WDM-PON system, each ONU uses a different wavelength, and each point-to-point connection is configured and operates according to a pre-designed wavelength, and as the number of wavelengths increases, the number of types of required ONUs increases, which causes a serious warehousing problem, which is particularly prominent for ONUs. Therefore, the solution of the fixed wavelength ONU is difficult to be applied to the commercial WDM-PON system, so that the use of colorless ONUs has become a consensus of the related research of the current WDM-PON, that is, each ONU can generate different wavelength capabilities, and the ONUs can work on the required wavelength through automatic configuration, so as to meet the pre-designed wavelength pair communication. The colorless ONU-based technical scheme is the mainstream of a WDM-PON system.

The tunable laser is a laser that uses a tunable wavelength to allow the ONU to operate at different wavelengths, and the tunable laser also operates at a specific wavelength, but the wavelength can be tuned by auxiliary means, such as electrical tuning, temperature tuning, and mechanical tuning, so that the same laser can be used in the system to generate different operating wavelengths. The temperature tuning cost is low, but the adjustable range is too low; the mechanical tuning structure is complex and the stability is poor; the production process of the electrically tuned laser is complex and high in cost. Just because the tunable laser is more complicated than the laser used in the traditional PON system and the price is higher, the mass popularization and use of the current WDM-PON system are affected.

In view of the above, overcoming the drawbacks of the prior art is an urgent problem in the art.

[ summary of the invention ]

The invention aims to solve the technical problems that the temperature tuning cost is low, but the adjustable range is too low; the mechanical tuning structure is complex and the stability is poor; the production process of the electrically tuned laser is complex and high in cost. Just because the tunable laser is more complicated than the laser used in the traditional PON system and the price is higher, the mass popularization and use of the current WDM-PON system are affected.

The invention adopts the following technical scheme:

in a first aspect, the present invention provides a cross-locked wavelength tunable high-speed laser, including a first FP laser, a second FP laser, a filter, and a coupling optical path structure, specifically:

the first FP laser and the second FP laser realize the coupling of comb wave signals transmitted by the first FP laser and the second FP laser through the coupling optical path structure; the filter is further arranged on a coupling optical path of the first FP laser and the coupling optical path structure so as to filter out a longitudinal mode with a specified wavelength in the first FP laser and enter the coupling optical path structure;

the first FP laser and/or the second FP laser are/is further used for obtaining a regulation signal so as to adjust the corresponding appointed-level longitudinal modes of the first comb wave emitted by the first FP laser and the second comb wave emitted by the second FP laser to complete wavelength matching, and therefore cross locking of the target output wavelength is completed.

Preferably, the first FP laser is a continuous light multi-longitudinal mode FP laser; the second FP laser is a multi-longitudinal-mode FP laser which is directly modulated at a high speed; and after the longitudinal mode with the specified wavelength of the first FP laser enters the coupling light path structure, part of the optical signals enter the second FP laser to complete the wavelength locking of the multi-longitudinal mode signals of the second FP laser.

Preferably, the first FP laser center wavelength is λ a, the second FP laser center wavelength is λ b, and L is a maximum usable wavelength band between the first FP laser and the second FP laser, where λ a ═ λ b-L is satisfied.

Preferably, the coupling optical path structure includes a first lens, a second lens and a semi-reflective glass slide, wherein the first FP laser is optically coupled to the first lens, and the second FP laser is optically coupled to the second lens;

the first lens and the second lens are located on one side of the semi-reflective glass slide in a mode of forming a 90-degree included angle relative to an optical axis, and emergent light of the first lens and the second lens is respectively arranged on the light path structure layout of the semi-reflective glass slide in a mode of 45-degree incident angles.

Preferably, the coupling optical path structure further includes a reflector, the reflector is disposed on the optical axis of the first FP laser, and is respectively located on two sides of the semi-reflective glass slide with the first FP laser, specifically:

after the optical signal of the first FP laser is filtered by the filter and the part of the semi-reflective glass slide is transmitted, the reflected light passing through the reflector returns to the first FP laser through the semi-reflective glass slide, the filter plate and the first lens, so that the output optical signal of the first FP laser is transmitted to the reflector after being filtered by the filter plate, and the wavelength locking is enhanced.

Preferably, a first TEC and a second TEC are respectively disposed corresponding to the first FP laser and the second FP laser, specifically:

the first TEC and the second TEC are semiconductor refrigerating sheets respectively and are used for adjusting the working temperature of the first FP laser and the working temperature of the second FP laser, so that the working state and the wavelength of the first FP laser and the working state and the wavelength of the second FP laser are stabilized at target values.

Preferably, the regulation signal and the wavelengths and the optical powers of the two FP lasers form a preset relationship;

the regulation signal comprises the working current control of the first FP laser and/or the second FP laser; and the working temperature control of the first TEC and/or the second TEC is also included.

Preferably, a first backlight detector and a second backlight detector are respectively arranged corresponding to the first FP laser and the second FP laser, specifically:

and the first backlight detector of the first FP laser and the second backlight detector of the second FP laser determine to regulate and control output optical signals of the first FP laser and the second FP laser to meet the cross-locking requirement of target output wavelength by detecting backlight signals of the corresponding first FP laser and the corresponding second FP laser.

Preferably, the filter is specifically an FP etalon filter, and an optical splitter is further disposed on an outgoing light path of the corresponding cross-locked wavelength tunable high-speed laser, specifically:

the FP etalon filter is used for enabling the wavelengths of the wavelength interval r to periodically pass through;

and each port of the optical splitter enables the wavelength interval r of the FP etalon filter to be equal to the wavelength interval which can be passed by each port in the optical splitter through an optical signal with a correspondingly formulated wavelength, so that the wavelength selected by the FP etalon filter is just output through the corresponding port of the optical splitter.

Preferably, the FP etalon filter wavelength spacing r is chosen to be different from the first FP laser longitudinal mode wavelength spacing m so that the FP etalon filter only allows one longitudinal mode of the laser to pass through at a time.

In a second aspect, the present invention further provides a method for implementing a cross-locked wavelength tunable high-speed laser, using the cross-locked wavelength tunable high-speed laser according to the first aspect, where the cross-locked wavelength tunable high-speed laser is disposed in an optical module, and the method includes:

the method comprises the following steps that an MCU of an optical module obtains a target wavelength which needs to be adjusted by a system;

the MCU of the optical module searches a parameter table stored during parameter calibration according to the received target wavelength, wherein the parameters store data series consisting of spectral wavelength, working temperature and working current parameters corresponding to the first FP laser and the first FP laser;

and the MCU of the optical module sets the working temperature and the working current of the first FP laser and the working temperature and the working current of the second FP laser according to the parameter table, so that the output optical signal meets the target wavelength setting.

Preferably, when spectral wavelength matching is carried out, a larger optical power longitudinal mode of the first FP laser is selected to lock a smaller optical power longitudinal mode of the second FP laser; and selecting a smaller optical power longitudinal mode of the first FP laser to lock a larger optical power longitudinal mode of the second FP laser, so that the difference between the optical powers of the locked wavelengths output by the cross-locked wavelength-tunable high-speed laser is smaller.

Preferably, when tunable wavelength tuning is performed, the implementation method includes:

if lambda a + m1 is used as the central wavelength to serve as the output of the cross-locked wavelength-tunable high-speed laser, the lambda a + m1 longitudinal mode of the first FP laser is aligned with the corresponding transmission central wavelength of the FP etalon filter by adjusting the temperature of the first TEC and the working current of the first FP laser;

the single longitudinal mode light transmitted by the first FP laser passes through the 45-degree semi-reflective glass slide, and a part of light is reflected to the second FP laser and is used for locking the wavelength of the second FP laser; the other part of the light is transmitted to the reflecting mirror, the reflected light of the reflecting mirror is reflected back to the optical signal emitted by the first FP laser through the semi-reflective glass sheet, the etalon filter plate and the first lens, in addition, part of the output light of the locked second FP laser is emitted to the first FP laser through the second lens, the semi-reflective glass sheet, the etalon filter plate and the first lens, so that the optical power of other wavelengths of the first FP laser is inhibited, and the emitted wavelength is locked to lambda a + m 1;

by adjusting the temperature of the second TEC and the working current of the second FP laser, the lambda b-kn longitudinal mode wavelength of the second FP laser is equal to or close to lambda a + m1, so that the optical power of other wavelengths of the second FP laser is suppressed, the emission wavelength is locked to the lambda a + m1 wavelength, namely the lambda b-kn longitudinal mode wavelength, the light emitted by the second FP laser is single longitudinal mode laser, and a part of the light is transmitted out of the assembly from the semi-reflective glass slide to become signal light; the other part is reflected to the first FP laser and is used for locking the wavelength of the first FP laser.

In a third aspect, the present invention further provides a control apparatus for a cross-locked wavelength tunable high-speed laser, including one or more processors 21 and a memory 22;

the processor 21 and the memory 22 may be connected by a bus or other means;

the memory 22, which is a nonvolatile computer-readable storage medium, may be used to store nonvolatile software programs and nonvolatile computer-executable programs, such as the control method of the cross-locked wavelength tunable high-speed laser in the second aspect; the processor 21 executes the control method of the cross-locked wavelength tunable high-speed laser by executing a non-volatile software program and instructions stored in the memory 22.

The invention adopts two FP lasers with adjustable central wavelengths, and carries out cross locking in a mode of adding a filter between the first FP laser, thereby realizing single-wavelength lasing. When the second FP laser is in a wavelength locking state, the high-speed performance is improved to solve the problem of high-speed modulation.

In a preferred scheme of the invention, the central wavelength and the longitudinal mode interval gain spectrum characteristics of the first FP laser and the second FP laser are mutually compensated, so that the effect of flattening the output light power of different wavelengths is achieved.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic structural diagram of a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a cross-locking wavelength tunable wavelength locking relationship provided in an embodiment of the present invention;

FIG. 3 is a schematic diagram of an optical coupling structure in a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a band TEC in a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention;

FIG. 5 is a flow chart of a method for implementing a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention;

FIG. 7 is a flow chart of a cross-locked wavelength tunable high-speed laser calibration provided by an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an apparatus according to an embodiment of the present invention.

[ detailed description ] embodiments

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are for convenience only to describe the present invention without requiring the present invention to be necessarily constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The fabry-perot laser (FP-LD, also described as FP laser in the embodiments of the present invention) is the most common and most common semiconductor laser, and is mainly characterized in that the resonant cavity of the laser is formed by two cleavage planes of semiconductor materials, and the fabrication technology of the FP laser adopted in the existing optical fiber communication is quite mature, and has the characteristics of low cost and convenience for mass production. The FP laser utilizes a pair of mutually parallel reflectors to carry out longitudinal mode selection, the length of the laser is generally in the magnitude of hundreds of micrometers, the corresponding mode spacing is in the magnitude of about 1nm, the gain spectral width of the laser reaches in the magnitude of tens of nm, the FP laser is a comb-shaped spectrum of multi-longitudinal mode lasing, and the application of the FP laser in high speed and long distance is limited by the characteristics of the multi-longitudinal mode.

The inventor researches and finds that the comb spectrum of the FP laser has a plurality of longitudinal modes to start oscillation freely, injection locking means that when external optical signals are injected into the FP laser, when the difference between the wavelength of the injected light and a certain longitudinal mode wavelength of the injected FP laser is within a certain range and the power of the injected optical signals exceeds a certain value, the free oscillation mode of the injected FP laser is inhibited, the output wavelength of the injected FP laser is locked on the wavelength of the external injection laser, and the longitudinal modes of other wavelengths are inhibited. In addition, studies have shown that the high speed performance of injection-locked lasers can be greatly improved.

Example 1:

embodiment 1 of the present invention provides a cross-locked wavelength-tunable high-speed laser, and as shown in fig. 1, a first FP laser, a second FP laser, a filter, and a coupling optical path structure specifically include:

the first FP laser and/or the second FP laser are/is further used for obtaining a regulation signal so as to adjust the corresponding appointed-level longitudinal modes of the first comb wave emitted by the first FP laser and the second comb wave emitted by the second FP laser to complete wavelength matching, and therefore cross locking of the target output wavelength is completed. As shown in fig. 2, a schematic diagram of a corresponding longitudinal mode wavelength effect of a first FP laser and a second FP laser, and a schematic diagram of an output effect of cross-locking of the two lasers under test are provided for an embodiment of the present invention. As can be seen from fig. 2, the longitudinal mode wave output by the first FP laser and the longitudinal mode wave output by the second FP laser complete cross locking in the gray scale peak band shown in fig. 2, and the final output effect is as the effect graph indicated by the right arrow in fig. 2; the implementation principle is that a filter filters out longitudinal mode waves λ a + m1 marked with gray in a first FP laser on the left side in fig. 2, and the longitudinal mode waves λ a + m1 are input into a second FP laser through a coupling optical path structure part to realize locking of the corresponding second FP laser on a corresponding target output optical signal, so as to form a comb-shaped wave optical signal similar to the right side in fig. 2, and the frequency value of the longitudinal mode waves λ a + m1 in the first FP laser shown in the corresponding figure is exactly the same as the frequency value of the longitudinal mode waves λ b-nk in the second FP laser, so that cross-locking of corresponding longitudinal mode waves is completed, and single longitudinal mode output shown on the right side in fig. 2 is formed. It should be noted that the comb wave of the second FP laser shown on the left side in fig. 2 is an effect diagram in which the output optical signal meets the setting requirement of the target wavelength by simply setting the working temperature and the working current of the second FP laser through the MCU of the optical module according to the parameter table before the cross-over frequency locking is not completed, that is, the frequency value of the longitudinal mode wave λ a + m1 in the first FP laser is exactly the same as the frequency value of the longitudinal mode wave λ b-nk in the second FP laser. After the second FP laser completes cross-frequency locking, as shown in the comb effect diagram of fig. 2, the peak region shifts to the position of the longitudinal mode wave λ b-nk shown in fig. 2 (not shown, which is described here specifically).

In a specific implementation process, in order to achieve a better regulation effect and achieve accurate regulation in a complex environment, an embodiment of the present invention further provides a preferred combination scheme, where a first backlight detector and a second backlight detector are respectively disposed at positions corresponding to a first FP laser and a second FP laser, and output optical signals of the first FP laser and the second FP laser are determined to meet a cross-locking requirement of a target output wavelength by detecting backlight signals of the corresponding first FP laser and the second FP laser.

The embodiment of the invention adopts two FP lasers with adjustable central wavelengths, and carries out cross locking in a mode of adding a filter in the middle of the first FP laser, thereby realizing single-wavelength lasing. When the second FP laser is in a wavelength locking state, the high-speed performance is better than that of the first FP laser, so that the problem of high-speed modulation is solved. Based on the coupling optical path structure provided by the embodiment of the invention, in the principle of realizing the optical path, after the longitudinal mode with the specified wavelength of the first FP laser enters the coupling optical path structure, part of the optical signal enters the second FP laser, and the wavelength locking of the multi-longitudinal mode signal of the second FP laser is completed; and the optical signal output by the second FP laser is also partially reflected to the first FP laser through the semi-reflective glass slide, so that the output wavelength locking effect of the first FP laser is further enhanced, and the process of mutual cross locking is completed.

In the embodiment of the invention, the first FP laser is a continuous light multi-longitudinal mode FP laser, and the first FP laser is characterized by higher light output power due to longer cavity length, so that the FP laser for communication can reach more than 10 mW and even higher; the second FP laser is a high-speed directly modulated multi-longitudinal mode FP laser, the cavity length of the second FP laser is short, and the light-emitting power of the current 25Gbps FP laser is generally 5mW to 7 mW.

In order to realize the wavelength-tunable effect within the interval range of the present invention, the following setting parameters are taken as examples, the center wavelength of the first FP laser is λ a, the center wavelength of the second FP laser is λ b, and L is the maximum available wavelength band between the first FP laser and the second FP laser; λ a is chosen not to be equal to λ b, and is such that λ a ═ λ b-L. The temperature and the current of the FP laser can only finely adjust the wavelength, generally the maximum wavelength is only 3-4 nm, and the multichannel requirement of WDM application cannot be met; and through the multi-longitudinal-mode interlocking of the 2 FP lasers, the wavelength adjustability in a range of 10-20 nm can be realized, and the technical requirements of WDM PON multichannel wavelength tunable colorless ONU and the like can be realized.

As shown in fig. 3, an implementation structure of a coupled optical path structure provided in an embodiment of the present invention includes a first lens, a second lens, and a semi-reflective glass slide, and a reflector is added to make the locking optical power from the first FP laser to the second FP laser higher. The first FP laser is coupled with the first lens light path, and the second FP laser is coupled with the second lens light path;

In order to realize precise adjustment and control of the wavelength, in combination with the embodiment of the present invention, there is also a preferred implementation scheme, wherein the first FP laser and the second FP laser are correspondingly provided with a first TEC (all referred to as a semiconductor Cooler in chinese) and a second TEC, as shown in fig. 4, specifically:

the first TEC and the second TEC are semiconductor refrigerating chips respectively and are used for adjusting the work of the first FP laser and the second FP laser, and the work states and the wavelengths of the first FP laser and the second FP laser are stabilized at target values.

The control signal and the wavelengths and the optical powers of the two FP lasers form a preset relation;

the regulation signal comprises the working current control of the first FP laser and/or the second FP laser; the working temperature control of the first TEC and/or the second TEC is also included;

wherein, in general, the central wavelength of the multi-longitudinal mode increases by about 0.1nm when the temperature rises by 1 ℃; for every 1mA increase of the working current, the central wavelength of the multi-longitudinal mode is increased by about 0.01 nm. The optical power will decrease when the temperature increases; the operating current increases and the optical power increases. By integrating the TEC temperature (including the first TEC and the second TEC) and the working current, the multi-longitudinal-mode wavelength and the optical power of the laser can be controlled.

In the embodiment of the present invention, a specific implementation manner is further provided for the filter, specifically, the filter is an FP etalon filter, and an optical splitter is further disposed on an outgoing light path of the corresponding cross-locked wavelength tunable high-speed laser, specifically:

each port of the optical splitter (which may be implemented, for example, using an Arrayed Waveguide Grating (AWG), passes an optical signal of a corresponding established wavelength, so that the FP etalon filter wavelength interval r and the wavelength interval that each port of the optical splitter can pass are equal, so that the wavelength selected by the FP etalon filter is just output through the corresponding port of the optical splitter.

The wavelength interval r of the selected FP etalon filter is different from the wavelength interval m of the longitudinal mode of the first FP laser, so that the FP etalon filter only allows one longitudinal mode of the laser to pass through at a time.

Taking 16 tunable wavelengths (frequency 191.70 THz-193.20 THz) as an example, the channel spacing frequency is 100GHz, and the wavelength frequencies to be tuned are 191.70, 191.80, 191.90, 192.00, 192.10, 192.20, 192.30, 192.40, 192.50, 192.60, 192.70, 192.80, 192.90, 193.00, 193.10, and 193.20THz in sequence, for example, by using the filter provided by the embodiment of the present invention, the wavelengths that can pass through the filter are also the series of wavelengths; the first FP laser with the center wavelength of 192.40THz and the longitudinal mode spacing of 155GHz can be selected, and the longitudinal mode wavelengths are 191.315, 191.470, 191.625, 191.780, 191.935, 192.090, 192.245, 192.400, 192.555, 192.710, 192.865, 193.020, 193.175, 193.330, 193.485 and 193.640THz in sequence, at this time, only the center wavelength longitudinal mode 192.40THz corresponds to the filter provided by the embodiment of the present invention, and other longitudinal modes cannot penetrate through the filter. When the first wavelength 191.70THz needs to be adjusted, the difference between the longitudinal modes 191.625THz and 191.70THz of the first FP laser is 75GHz (about 0.6nm), the longitudinal mode 191.625THz is moved and aligned to 191.70THz by comprehensively adjusting the temperature and the current of the first FP laser, and the wavelengths of the longitudinal modes are 191.390, 191.545, 191.700, 191.855, 192.010, 192.165, 192.320, 192.475, 192.630, 192.785, 192.940, 193.095, 193.250, 193.405, 193.560 and 193.715THz in sequence, only 191.70THz corresponds to the filter provided by the embodiment of the invention, and other longitudinal modes cannot penetrate through the filter.

Example 2:

an embodiment of the present invention provides a method for implementing a cross-locked wavelength tunable high-speed laser, where the cross-locked wavelength tunable high-speed laser described in embodiment 1 is used, and the cross-locked wavelength tunable high-speed laser is disposed in an optical module, and as shown in fig. 5, the method includes:

in step 201, the MCU of the optical module acquires a target wavelength that needs to be adjusted by the system. Typically data sent over the interface between the optical module and the master, such as the I2C bus.

In step 202, the MCU of the optical module searches a parameter table stored during parameter calibration according to the received target wavelength, where the parameters store data series consisting of the spectral wavelength, the operating temperature, and the operating current parameters corresponding to the first FP laser and the first FP laser.

In step 203, the MCU of the optical module sets the operating temperature and operating current of the first FP laser and the operating temperature and operating current of the second FP laser according to the parameter table, so that the output optical signal meets the target wavelength setting.

The embodiment of the invention adopts two FP lasers with adjustable central wavelengths, and carries out cross locking in a mode of adding a filter in the middle of the first FP laser, thereby realizing single-wavelength lasing. When the second FP laser is in a wavelength locking state, the high-speed performance is better than that of the first FP laser, so that the problem of high-speed modulation is solved.

In the embodiment of the invention, when spectral wavelength matching is carried out, a preferable implementation scheme exists, and a larger optical power longitudinal mode of a first FP laser is selected to lock a smaller optical power longitudinal mode of a second FP laser; and selecting a smaller optical power longitudinal mode of the first FP laser to lock a larger optical power longitudinal mode of the second FP laser, so that the difference between the optical powers of the locked wavelengths output by the cross-locked wavelength-tunable high-speed laser is smaller.

In the embodiment of the present invention, when tuning the tunable wavelength, the implementation method includes:

the single longitudinal mode light transmitted by the first FP laser passes through the 45-degree semi-reflective glass slide, and a part of light is reflected to the second FP laser and is used for locking the wavelength of the second FP laser; the other part of the light is transmitted to a reflecting mirror, the reflected light of the reflecting mirror is reflected back to the optical signal emitted by the first FP laser through the 45-degree semi-reflecting glass sheet, the etalon filter and the first lens, and in addition, a part of the output light of the locked second FP laser is emitted to the first FP laser through the second lens, the semi-reflecting glass sheet, the etalon filter and the first lens, so that the optical power of other wavelengths of the first FP laser is inhibited, and the emitted wavelength is locked to lambda a + m 1;

by adjusting the temperature of the second TEC and the working current of the second FP laser, the lambda b-kn longitudinal mode wavelength of the second FP laser is equal to or close to lambda a + m1, so that the optical power of other wavelengths of the second FP laser is suppressed, the emission wavelength is locked to the lambda a + m1 wavelength, namely the lambda b-kn longitudinal mode wavelength, the light emitted by the second FP laser is single longitudinal mode laser, and a part of the light is transmitted out of the assembly from the semi-reflective glass slide to become signal light; the other part is reflected to the first FP laser and is used for locking the wavelength of the first FP laser. The second FP laser is driven by the working current and the high-speed signal, and the second FP laser is in a locked state, so that the direct-modulation high-speed performance is improved, and the second FP laser is more suitable for high-speed communication. In the embodiment of the present invention, if the mirror as described in embodiment 1 is further introduced into the corresponding cross-locked wavelength tunable high-speed laser, the locked light introduced into the first FP laser will simultaneously include a part of light from the second FP laser and a part of light of the first FP laser reflected by the mirror.

In the embodiment of the present invention, it is determined that the cross-locking requirement for the target output wavelength is satisfied by adjusting and controlling the output optical signals of the first FP laser and the second FP laser by detecting the backlight signals of the corresponding first FP laser and the second FP laser at the first backlight detector of the first FP laser and the second backlight detector of the second FP laser.

Example 3:

the embodiment of the invention is based on embodiment 1, and proposes a cross-locking wavelength-tunable high-speed laser implementation scheme, and compared with embodiment 1, the embodiment of the invention integrates multiple extension schemes set forth in embodiment 1, and performs characteristic optimization of a locked light portion, as shown in fig. 6, the embodiment mainly includes a main laser module FP-LD0, a TEC0, a backlight detector PD0 and a lens 0, a slave laser module FP-LD1, a TEC1, a backlight detector PD1 and a lens 1, an optical path control module FP standard filter, a 45-degree half-reflecting half-transmitting mirror and a reflecting mirror (which are newly added feature objects in the embodiment of the invention). It is emphasized here that the corresponding "first" defining object in embodiment 1, embodied in the present embodiment with the reference number "0", and the corresponding "second" defining object, embodied in the present embodiment with the reference number "1", such as the first lens in embodiment 1, embodied in the present embodiment with the reference number "0"; also as in embodiment 1, the first FP laser is denoted as master laser FP-LD0 in embodiments of the present invention.

The main laser FP-LD0 adopts a continuous light multi-longitudinal mode FP laser, and is mainly characterized by higher light output power. The slave laser FP-LD1 adopts a multi-longitudinal mode FP laser with high speed and strong direct modulation performance. The central wavelength of the master laser is λ a, the central wavelength of the slave laser is λ b, as shown in fig. 2, the longitudinal mode wavelength interval of the master laser is m, the longitudinal mode interval of the slave laser is n, and L is the maximum available wavelength number of the tunable laser. Choosing λ a not equal to λ b and using λ a ═ λ b-L, the laser gain is characterized by the strongest relative optical power at the center wavelength, which decreases progressively further away from the center wavelength, as seen in fig. 2. The wavelength corresponding relation enables a larger optical power longitudinal mode of the master laser to lock a smaller optical power longitudinal mode of the slave laser, and the smaller optical power longitudinal mode of the master laser to lock a larger optical power longitudinal mode of the slave laser, so that the power change of different wavelength light output by the slave laser after locking is smaller and flatter.

The TEC0 and the TEC1 are semiconductor refrigerating chips respectively, and the working state and the wavelength of the laser are stabilized by adjusting the working of the two lasers. The current and the temperature have a certain relation with the wavelength and the optical power of the laser, and the central wavelength of the multi-longitudinal mode is increased by about 0.1nm when the temperature is increased by 1 ℃; for every 1mA increase in current, the center wavelength of the multiple longitudinal modes increases by about 0.01 nm. The optical power will decrease, the current will increase, and the optical power will increase with increasing temperature. By integrating the TEC temperature and the laser current, the multi-longitudinal-mode wavelength and the optical power of the laser can be controlled.

The filter is an FP etalon filter, which can allow wavelengths with a wavelength interval r to periodically pass through, an AWG is usually used as an optical splitter of the WDM PON, the wavelengths which can pass through each port of the optical splitter are different, and the wavelength intervals which can pass through each port are usually equidistant, so that the wavelength interval r of the FP etalon filter is equal to the wavelength interval which can pass through the AWG port of the optical splitter, and the wavelength selected by the FP etalon filter can just pass through the AWG port of the optical splitter. Meanwhile, the wavelength interval r of the selected FP etalon filter is different from the wavelength interval m of the longitudinal mode of the main laser, so that the FP etalon filter only allows one longitudinal mode of the laser to pass through at one time. If the wavelength is required to be continuously adjustable, the filter can adopt a continuously adjustable filter.

When tunable wavelength tuning is carried out, if λ a + m1 is needed to be used as a central wavelength output, the temperature of the TEC0 and the current of the FP0 are adjusted, so that the λ a + m1 longitudinal mode of the FP0 is aligned to the corresponding transmission central wavelength of the FP etalon filter, and thus single longitudinal mode light transmitted by the FP0 passes through a 45-degree semi-reflective glass slide, and a part of light is reflected to the FP1 laser to lock the wavelength of the FP 1; the other part of the light is transmitted to the mirror, the reflected light of the mirror is reflected back to the laser FP0 through the semi-reflective glass sheet, the etalon filter and the lens 0, and in addition, a part of the output light of the locked FP1 is emitted to the laser FP0 through the lens 1, the semi-reflective glass sheet, the etalon filter and the lens 0, so that the light power of other wavelengths of the laser FP0 is suppressed, and the emission wavelength is locked to lambda a + m 1. Meanwhile, the lambda b-kn longitudinal mode wavelength of the laser FP1 is equal to or close to lambda a + m1 by adjusting the temperature of the TEC1 and the current of the FP1, so that the optical power of other wavelengths of the laser FP1 is suppressed, the emission wavelength is locked to the lambda a + m1 wavelength, namely the lambda b-kn longitudinal mode wavelength, the light emitted by the FP1 is single longitudinal mode laser, and a part of the light is transmitted out of the assembly from the semi-reflective glass slide to become signal light; another part is reflected to the laser FP0 for locking the wavelength of the laser FP 0.

The laser FP1 is driven by current + high-speed signals, and the FP1 is in a locked state, so that the high-speed performance of direct modulation is improved, and the laser is more suitable for high-speed communication. The backlight detector PD1 and the backlight detector PD2 detect the wavelength locking state, and feed back the current for adjusting the temperature of TEC and FP to adjust the wavelength.

Example 4:

the embodiment of the present invention is applicable to the method content of embodiment 2, and proposes a cross-locked FP tunable laser calibration process, which is expressed by using the object name in embodiment 3, as shown in fig. 7, including:

in step 301, the output of the tunable laser is connected to a spectrometer for monitoring the output wavelength of the tunable laser.

In step 302, the temperature and current are set according to the physical characteristics of the lasers FP0 and FP1, thereby controlling the wavelength of the lasers.

In step 303, the spectrometer monitors the tunable laser output spectrum index, which may cause the output wavelength of the tuned laser to differ somewhat from the theoretical data due to manufacturing errors of lasers FP0 and FP 1. The temperature and current can then be fine tuned until the spectral indicators are at their optimum.

In step 304, parameters such as the spectral wavelength, the temperature, and the current at which the spectrum is in the optimum state are recorded.

In step 305, the temperature and current of FP0 and FP1 are reset cyclically; fine tuning is carried out until the spectrum index is in the best state, and parameters are recorded and stored. Finally, a parameter table composed of parameters such as spectral wavelength, temperature, current and the like is formed, usually, an MCU subsystem is arranged in the optical module, and the related parameter table can be stored in a memory.

In step 306, the tunable laser calibration is completed after all the required wavelengths and parameter tables have been calibrated.

Example 4:

fig. 8 is a schematic diagram of a control apparatus of a cross-locked wavelength tunable high-speed laser according to an embodiment of the present invention. The control arrangement of the cross-locked wavelength tunable high-speed laser of the present embodiment comprises one or more processors 21 and a memory 22. In fig. 8, one processor 21 is taken as an example.

The processor 21 and the memory 22 may be connected by a bus or other means, and fig. 8 illustrates the connection by a bus as an example.

The memory 22, which is a nonvolatile computer-readable storage medium, may be used to store a nonvolatile software program and a nonvolatile computer-executable program, such as the control method of the cross-locked wavelength tunable high-speed laser in embodiment 1. The processor 21 executes the control method of the cross-locked wavelength tunable high-speed laser by executing a non-volatile software program and instructions stored in the memory 22.

The memory 22 may include high speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, the memory 22 may optionally include memory located remotely from the processor 21, and these remote memories may be connected to the processor 21 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The program instructions/modules are stored in the memory 22 and, when executed by the one or more processors 21, perform the method for controlling a cross-locked wavelength tunable high-speed laser in embodiment 1 described above, for example, perform the steps shown in fig. 5 and 7 described above.

It should be noted that, for the information interaction, execution process and other contents between the modules and units in the apparatus and system, the specific contents may refer to the description in the embodiment of the method of the present invention because the same concept is used as the embodiment of the processing method of the present invention, and are not described herein again.

Those of ordinary skill in the art will appreciate that all or part of the steps of the various methods of the embodiments may be implemented by associated hardware as instructed by a program, which may be stored on a computer-readable storage medium, which may include: read Only Memory (ROM), Random Access Memory (RAM), magnetic or optical disks, and the like.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. The cross-locked wavelength-tunable high-speed laser is characterized in that a first FP laser, a second FP laser, a filter and a coupling optical path structure are as follows:

the first FP laser and/or the second FP laser are/is also used for acquiring a regulation signal so as to adjust the corresponding appointed-level longitudinal modes of the first comb wave emitted by the first FP laser and the second comb wave emitted by the second FP laser to complete wavelength matching, thereby completing the cross locking of the target output wavelength;

the cross-locked wavelength tunable high-speed laser is used for being arranged in an optical module;

the method comprises the following steps that an MCU of an optical module acquires a target wavelength required to be adjusted by a system;

2. The cross-locked wavelength tunable high-speed laser according to claim 1, wherein the first FP laser is a continuous light multi-longitudinal mode FP laser; the second FP laser is a multi-longitudinal-mode FP laser which is directly modulated at a high speed; and after the longitudinal mode with the specified wavelength of the first FP laser enters the coupling light path structure, part of the optical signals enter the second FP laser to complete the wavelength locking of the multi-longitudinal mode signals of the second FP laser.

3. The cross-locked wavelength tunable high-speed laser according to claim 1, wherein the first FP laser center wavelength is λ a, the second FP laser center wavelength is λ b, and L is a maximum usable wavelength band between the first FP laser and the second FP laser, where λ a ═ λ b-L is satisfied.

4. The cross-locked wavelength tunable high-speed laser according to claim 1, wherein the coupling optical path structure comprises a first lens, a second lens and a semi-reflective glass slide, wherein the first FP laser is optically coupled to the first lens and the second FP laser is optically coupled to the second lens;

5. The cross-locked wavelength tunable high-speed laser according to claim 4, wherein the coupling optical path structure further comprises a mirror, the mirror is disposed on the optical axis of the first FP laser and is respectively located on two sides of the semi-reflective glass slide with the first FP laser, specifically:

6. The cross-locked wavelength-tunable high-speed laser according to claim 1, wherein a first TEC and a second TEC are respectively disposed corresponding to the first FP laser and the second FP laser, specifically:

7. The cross-locked wavelength tunable high-speed laser according to claim 6, wherein the control signal has a predetermined relationship with the wavelengths and optical powers of the two FP lasers;

8. The cross-locked wavelength tunable high-speed laser according to claim 1, wherein a first backlight detector and a second backlight detector are respectively disposed corresponding to the first FP laser and the second FP laser, specifically:

9. The cross-locked wavelength tunable high-speed laser according to any one of claims 1 to 8, wherein the filter is specifically an FP etalon filter, and an optical splitter is further disposed on an optical output path of the corresponding cross-locked wavelength tunable high-speed laser, specifically:

10. The cross-locked wavelength tunable high-speed laser according to claim 9, wherein the FP etalon filter wavelength spacing r is chosen to be different from the first FP laser longitudinal mode wavelength spacing m such that the FP etalon filter only allows one longitudinal mode of the laser to pass through at a time.

11. A method for implementing a cross-locked wavelength tunable high-speed laser, wherein the cross-locked wavelength tunable high-speed laser according to any one of claims 1 to 10 is used, and the cross-locked wavelength tunable high-speed laser is disposed in an optical module, and the method comprises:

12. The method of claim 11, wherein when performing spectral wavelength matching, a larger optical power longitudinal mode of a first FP laser is selected to lock a smaller optical power longitudinal mode of a second FP laser; and selecting a smaller optical power longitudinal mode of the first FP laser to lock a larger optical power longitudinal mode of the second FP laser, so that the difference between the optical powers of the locked wavelengths output by the cross-locked wavelength-tunable high-speed laser is smaller.

13. The method of claim 11, wherein when performing tunable wavelength tuning, the method comprises: