Background
In recent years, with the rapid development of the internet of things, the optical fiber communication system is used as an important support for the internet of things, and the development of the optical fiber communication system is more emphasized. In the field of long-distance backbone networks, with the maturity and development of optical transmission technology, the construction of trunk transmission networks has been hot in the world, and the transmission bandwidth and the transmission capacity are rapidly developed.
With the development of optical fiber communication systems, the development of optical devices also faces opportunities and challenges, and how to develop optical devices with excellent performance and low price has become a primary problem. Silicon-based optoelectronic devices have the advantages of easy integration, low process cost and the like, and have attracted extensive attention of researchers in recent years. Si (silicon) material is used as the traditional material in the field of microelectronics, has incomparable advantages of other materials in the aspects of processing technology and manufacturing cost, and the silicon-based photoelectron integration technology is produced at the same time. The photodetector, one of the important representative elements in silicon-based optoelectronic integration technology, functions to convert an incident optical signal into an electrical signal for analysis by subsequent signal processing circuitry. The silicon-based germanium photoelectric detector is continuously optimized in structure and further improved in performance after being developed for more than ten years.
In recent years, under continuous innovative efforts in academia and industry, silicon-based electro-optical modulators with various high performance indexes are continuously proposed and optimized, and part of indexes reach the level of commercial lithium niobate and three-five electro-optical modulators.
The main structure of the silicon-based electro-optical modulator is a PN junction (space charge region), and the silicon-based electro-optical modulator is mainly divided into a carrier injection structure and a carrier depletion structure according to different working modes. The PN junction is formed by an N-type doped region (hereinafter, may be referred to as an N-region) and a P-type doped region (hereinafter, may be referred to as a P-region) in close contact, and the contact interface is called a metallurgical junction interface.
For the silicon-based electro-optical modulator with the two structures, carriers are transported through a lightly doped region of a slab (electrode plate) electrode. The same electrode arrangement is used for the P and N regions. For a conventional silicon electro-optic modulator, the P-type slab region and the N-type slab region have the same length. However, the main carriers of the P region are holes, the main carriers of the N region are electrons, and the electrons and the holes have different mobility rates. The mobility of electrons in silicon is 1350cm2/(vs), while the mobility of holes is only 480cm2/(vs), and the mobility of electrons is about three times that of holes, so the carrier transport time is often determined by the carrier transport time of holes. And the long slab region can reduce the absorption of the electrode to optical signals and reduce the insertion loss of the silicon-based electro-optical modulator. And the short slab region can improve the bandwidth of the silicon-based electro-optical modulator.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a conventional silicon-based electro-optic modulator. As shown in fig. 1, the conventional silicon-based electro-optic modulator includes a first silicon element region 11, a first carrier region 12, a P-type doped region 13, a second silicon element region 14, a second carrier region 15, and an N-type doped region 16, wherein the modulation arm length of a modulation arm 17 of the P-type doped region 13 is equal to the modulation arm length of a modulation arm 18 of the N-type doped region 16. The transmission time of the current carrier of the traditional silicon-based electro-optical modulator is often determined by the transmission time of the current carrier of a cavity, the long slab region can reduce the absorption of an electrode to an optical signal and reduce the insertion loss of the silicon-based electro-optical modulator, and the short slab region can improve the bandwidth of the silicon-based electro-optical modulator. The arm lengths of the two modulation arms of the conventional silicon-based electro-optical modulator are equal, the influence of the arm lengths of the modulation arms on the insertion loss and the bandwidth of the silicon-based electro-optical modulator is fixed, and the influence of the insertion loss and the bandwidth of the silicon-based electro-optical modulator cannot be optimized by setting the arm lengths of the modulation arms.
Disclosure of Invention
In view of this, the present invention provides a method and an apparatus for setting a modulation arm length based on a silicon-based electro-optical modulator, which can implement that the silicon-based electro-optical modulator can set the arm length of the modulation arm to optimize the influence of insertion loss and bandwidth of the silicon-based electro-optical modulator.
According to one aspect of the invention, a modulation arm length setting method based on a silicon-based electro-optical modulator is provided, which comprises the following steps:
the silicon-based electro-optic modulator is provided with a modulation arm length of a modulation arm of a P-type doping area and a modulation arm length of a modulation arm of an N-type doping area which are not equal;
after the length of the modulation arm of the P-type doping region is not equal to that of the modulation arm of the N-type doping region, the migration of the electron carrier in one carrier region and the hole carrier in the other carrier region achieves the matching effect.
Wherein, the silicon-based electro-optic modulator sets that the modulation arm length of the modulation arm of the P type doping region is unequal to the modulation arm length of the modulation arm of the N type doping region, and comprises:
the silicon-based electro-optical modulator sets the relation between the modulation arm length of the modulation arm of the N-type doping area and the modulation arm length of the modulation arm of the P-type doping area to be the first multiple relation according to the first multiple relation of the mobility of the electron carrier in one carrier area and the mobility of the hole carrier in the other carrier area.
Wherein, the silicon-based electro-optic modulator sets that the modulation arm length of the modulation arm of the P type doping region is unequal to the modulation arm length of the modulation arm of the N type doping region, and comprises:
the silicon-based electro-optical modulator sets the modulation arm length of the modulation arm of the N-type doping region to be 2.8 times of the modulation arm length of the modulation arm of the P-type doping region according to the fact that the mobility of an electron carrier in one carrier region is 2.8 times of the mobility of a hole carrier in the other carrier region.
After the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables the migration of an electron carrier in one carrier region and a hole carrier in the other carrier region to achieve a matching effect, and the silicon-based electro-optic modulator comprises the following components:
after the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables the quantity of electron carriers in one carrier region and the quantity of hole carriers in the other carrier region to be simultaneously and respectively injected into the P-type doping region and the N-type doping region, and enables the migration of the electron carriers in the one carrier region and the hole carriers in the other carrier region to achieve the matching effect.
After the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables the migration of an electron carrier in one carrier region and a hole carrier in the other carrier region to achieve a matching effect, and the silicon-based electro-optic modulator comprises the following components:
after the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables hole carriers in the P-type doping region and electron carriers in the N-type doping region to be simultaneously transported to the one carrier region and the other carrier region respectively, and enables the migration of the electron carriers in the one carrier region and the hole carriers in the other carrier region to achieve the matching effect.
According to another aspect of the present invention, there is provided a silicon-based electro-optic modulator comprising:
the modulation arm length of the modulation arm of the P-type doping region is not equal to that of the modulation arm of the N-type doping region.
The modulation arm length of the modulation arm of the N-type doping region is a first multiple relation of the modulation arm length of the modulation arm of the P-type doping region; wherein the first multiple relationship is a multiple of the mobility of electron carriers in the fourth carrier sub-region divided by the mobility of hole carriers in the third carrier sub-region.
And the modulation arm length of the modulation arm of the N-type doped region is 2.8 times that of the modulation arm of the P-type doped region.
Wherein the mobility of electron carriers in the fourth carrier sub-region matches the mobility of hole carriers in the third carrier sub-region.
It can be found that, in the above scheme, the silicon-based electro-optical modulator may set the length of the modulation arm in the P-type doped region to be unequal to the length of the modulation arm in the N-type doped region, and after setting the length of the modulation arm in the P-type doped region to be unequal to the length of the modulation arm in the N-type doped region, the migration of the electron carrier in one carrier region and the migration of the hole carrier in the other carrier region may achieve a matching effect, which may achieve that the silicon-based electro-optical modulator may set the arm length of the modulation arm to optimize the influence of its own insertion loss and bandwidth, and compromise the influence of the length of the modulation arm in the P-type doped region and the length of the modulation arm in the N-type doped region on the insertion loss and bandwidth to the optimum.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be noted that the following examples are only illustrative of the present invention, and do not limit the scope of the present invention. Similarly, the following examples are only some but not all examples of the present invention, and all other examples obtained by those skilled in the art without any inventive work are within the scope of the present invention.
The invention provides a modulation arm length setting method based on a silicon-based electro-optical modulator, which can realize that the silicon-based electro-optical modulator can set the arm length of a modulation arm to optimize the influence of the self insertion loss and bandwidth.
Referring to fig. 2, fig. 2 is a schematic flow chart of an embodiment of a method for setting the length of a modulation arm of a silicon-based electro-optic modulator according to the present invention. It should be noted that the method of the present invention is not limited to the flow sequence shown in fig. 2 if the results are substantially the same. As shown in fig. 2, the method comprises the steps of:
s201: the silicon-based electro-optic modulator is provided with a modulation arm length of a modulation arm of a P-type doping area and a modulation arm length of a modulation arm of an N-type doping area which are not equal.
The silicon-based electro-optical modulator may set a modulation arm length of a modulation arm of the P-type doped region to be unequal to a modulation arm length of a modulation arm of the N-type doped region, and may include:
the silicon-based electro-optical modulator sets the relation between the modulation arm length of the modulation arm of the N-type doping area and the modulation arm length of the modulation arm of the P-type doping area to be a first multiple relation according to the first multiple relation of the mobility of the electron carrier in one carrier area and the mobility of the hole carrier in the other carrier area.
The silicon-based electro-optical modulator may set a modulation arm length of a modulation arm of the P-type doped region to be unequal to a modulation arm length of a modulation arm of the N-type doped region, and may include:
the silicon-based electro-optical modulator sets the modulation arm length of the modulation arm of the N-type doping area to be 2.8 times of the modulation arm length of the modulation arm of the P-type doping area according to the fact that the mobility of electron carriers in one carrier area is 2.8 times of the mobility of hole carriers in the other carrier area.
S202: after the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables the migration of an electron carrier in one carrier region and a hole carrier in the other carrier region to achieve the matching effect.
After the length of the modulation arm of the P-type doped region and the length of the modulation arm of the N-type doped region are not equal, the silicon-based electro-optic modulator enables the migration of an electron carrier in one carrier region and a hole carrier in another carrier region to achieve a matching effect, and may include:
after the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optic modulator enables an equal amount of electron carriers in one carrier region and an equal amount of hole carriers in the other carrier region to be simultaneously and respectively injected into the P-type doping region and the N-type doping region, and enables the migration of the electron carriers in the one carrier region and the hole carriers in the other carrier region to achieve the matching effect.
After the length of the modulation arm of the P-type doped region and the length of the modulation arm of the N-type doped region are not equal, the silicon-based electro-optic modulator enables the migration of an electron carrier in one carrier region and a hole carrier in another carrier region to achieve a matching effect, and may include:
after the length of the modulation arm of the P-type doping region and the length of the modulation arm of the N-type doping region are not equal, the silicon-based electro-optical modulator enables hole carriers in the P-type doping region and electron carriers in the N-type doping region to be simultaneously transported to the one carrier region and the other carrier region respectively, and enables the migration of the electron carriers in the one carrier region and the hole carriers in the other carrier region to achieve the matching effect.
In the present embodiment, since in the silicon material, the electron carriers and the hole carriers have different mobilities. The mobility of the electron carrier is 1350cm2/(vs), the mobility of the hole carrier is only 480cm2/(vs), the mobility rate of the electron carrier is about 2.8 times of the mobility of the hole carrier, the silicon-based electro-optical modulator can be set to be 2.8 times of the length of the P-type slab region of the modulation arm of the N-type slab region, the same amount of the electron carrier and the same amount of the hole carrier in the two carrier regions can be respectively and simultaneously injected into the P-type doped region and the N-type doped region, or the carriers in the P-type doped region and the N-type doped region can be respectively and simultaneously transported to the corresponding carrier regions, so that the mobility of the electron carrier and the hole carrier achieves the matching effect.
In this embodiment, since the mobility of the electron carrier in the silicon material is 2.8 times of the mobility of the hole carrier according to the calculation, in the actual design of the silicon-based electro-optical modulator, the length of the N-type slab region may be set to be 2.8 times of the length of the P-type slab region, so for the silicon-based electro-optical modulator, carriers in the P-type doped region and the N-type doped region in the PN junction are injected or dissipated simultaneously, and thus the difference in the carrier mobility of the two different doping type semiconductors does not affect the characteristics of the silicon-based electro-optical modulator. In addition, the appropriate increase of the length of the N-type slab region can reduce the absorption of the electrode on the optical signal in the modulation region of the silicon-based electro-optical modulator on the basis of not affecting the bandwidth of the silicon-based electro-optical modulator.
It can be found that, in this embodiment, the silicon-based electro-optical modulator may set the length of the modulation arm in the P-type doped region to be not equal to the length of the modulation arm in the N-type doped region, and after setting the length of the modulation arm in the P-type doped region to be not equal to the length of the modulation arm in the N-type doped region, the migration of the electron carrier in one carrier sub-region and the migration of the hole carrier in the other carrier sub-region may achieve a matching effect, and it may be achieved that the silicon-based electro-optical modulator may set the arm length of the modulation arm to optimize the influence of the modulation arm on the insertion loss and the bandwidth, and the influence of the modulation arm length of the modulation arm in the P-type doped region and the modulation arm length of the modulation arm in the N-type doped region on the insertion loss and the bandwidth is balanced to the optimum.
The invention also provides a silicon-based electro-optical modulator, which can realize that the silicon-based electro-optical modulator can set the arm length of the modulation arm to optimize the influence of the insertion loss and the bandwidth of the silicon-based electro-optical modulator.
Referring to fig. 3, fig. 3 is a schematic structural diagram of a silicon-based electro-optic modulator according to an embodiment of the invention. In this embodiment, the silicon-based electro-optical modulator 30 is the silicon-based electro-optical modulator in the above method embodiment. In this embodiment, the silicon-based electro-optic modulator 30 includes a third silicon element region 31, a third carrier sub-region 32, a P-type doped region 33, a fourth silicon element region 34, a fourth carrier sub-region 35, and an N-type doped region 36, where the modulation arm length of the modulation arm 37 of the P-type doped region 33 is not equal to the modulation arm length of the modulation arm 38 of the N-type doped region 36.
Optionally, the modulation arm length of the modulation arm of the N-type doped region is a first multiple of the modulation arm length of the modulation arm of the P-type doped region; wherein the first multiple relationship is a multiple of the mobility of electron carriers in the fourth carrier sub-region 35 divided by the mobility of hole carriers in the third carrier sub-region 32.
Optionally, the modulation arm length of the modulation arm of the N-type doped region is 2.8 times longer than the modulation arm length of the modulation arm of the P-type doped region.
Optionally, the mobility of electron carriers in the fourth carrier region 35 and the mobility of hole carriers in the third carrier region 32 are matched.
Each unit module of the silicon-based electro-optical modulator 30 can respectively execute the corresponding steps in the above method embodiments, and therefore, the detailed description of each unit module is omitted here, and please refer to the description of the corresponding steps above.
It can be found that, in the above scheme, the silicon-based electro-optical modulator may set the length of the modulation arm in the P-type doped region to be unequal to the length of the modulation arm in the N-type doped region, and after setting the length of the modulation arm in the P-type doped region to be unequal to the length of the modulation arm in the N-type doped region, the migration of the electron carrier in one carrier region and the migration of the hole carrier in the other carrier region may achieve a matching effect, which may achieve that the silicon-based electro-optical modulator may set the arm length of the modulation arm to optimize the influence of its own insertion loss and bandwidth, and compromise the influence of the length of the modulation arm in the P-type doped region and the length of the modulation arm in the N-type doped region on the insertion loss and bandwidth to the optimum.
In the several embodiments provided in the present invention, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of a module or a unit is merely a logical division, and an actual implementation may have another division, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be substantially or partially implemented in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above description is only a part of the embodiments of the present invention, and not intended to limit the scope of the present invention, and all equivalent devices or equivalent processes performed by the present invention through the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.