阅读说明：本技术 一种光脉冲序列重频倍增控制装置及方法 (Optical pulse sequence repetition frequency multiplication control device and method ) 是由 谢启杰 纳全鑫 张楠 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种光脉冲序列重频倍增控制装置及方法,包括脉冲激光源,用于产生具有预设重频和预设脉宽的初始光脉冲序列；振幅调制模块,与脉冲激光源连接,用于对初始光脉冲序列的幅度进行调制,得到中间光脉冲序列；色散介质提供色散值以满足时域泰伯效应条件,与振幅调制模块连接,用于将中间光脉冲序列转化成重频倍增的目标光脉冲序列,并输出目标光脉冲序列,实现重频倍增倍数的灵活调节。(The invention discloses a device and a method for controlling the repetition frequency multiplication of an optical pulse sequence, which comprises a pulse laser source, a pulse frequency multiplier and a pulse width multiplier, wherein the pulse laser source is used for generating an initial optical pulse sequence with preset repetition frequency and preset pulse width; the amplitude modulation module is connected with the pulse laser source and is used for modulating the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse sequence; the dispersion medium provides a dispersion value to meet the condition of time domain Talbot effect, is connected with the amplitude modulation module and is used for converting the intermediate optical pulse sequence into a target optical pulse sequence with repetition frequency multiplication and outputting the target optical pulse sequence, thereby realizing the flexible adjustment of the repetition frequency multiplication multiple.)

1. An optical pulse train repetition frequency multiplication control apparatus, comprising:

a pulsed laser source for generating an initial sequence of optical pulses having a preset repetition frequency and a preset pulse width;

the amplitude modulation module is connected with the pulse laser source and is used for modulating the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse sequence;

and the dispersion medium is used for providing a dispersion value meeting the time domain Talbot effect condition, is connected with the amplitude modulation module, and is used for converting the intermediate optical pulse sequence into a target optical pulse sequence with repetition frequency multiplication and outputting the target optical pulse sequence.

2. An optical pulse train repetition frequency multiplication control apparatus according to claim 1,

the amplitude modulation module includes:

the optical splitter is connected with the pulse laser source and is used for splitting the initial optical pulse sequence into a first optical pulse sequence and a second optical pulse sequence;

the photoelectric detector is connected with the optical splitter and used for generating a clock signal corresponding to the first optical pulse sequence;

the code pattern generator is connected with the photoelectric detector and used for generating a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal;

and the electro-optical modulator is respectively connected with the code pattern generator and the optical splitter and is used for modulating the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain an intermediate optical pulse sequence.

3. The optical pulse train repetition frequency multiplication control device according to claim 2, wherein the amplitude modulation module further comprises:

and the optical delay line is arranged between the optical splitter and the electro-optical modulator and used for adjusting the time delay of the second optical pulse sequence when the binary code modulation signal and the second optical pulse sequence are misaligned in the time domain, so that the second optical pulse sequence and the binary code modulation signal are aligned in the time domain.

4. The optical pulse train repetition frequency multiplication control device according to claim 1, further comprising:

and the optical amplifier is connected with the dispersion medium and used for adjusting the power of the target optical pulse sequence and outputting the adjusted target optical pulse sequence.

5. The optical pulse train repetition frequency multiplication control device according to claim 1, wherein the pulse laser source is one of an active or passive mode-locked laser, a cavity-free structure pulse laser source, and a micro-ring resonator.

6. The optical pulse train repetition frequency multiplication control device according to claim 1, wherein the electro-optical modulator is one of a single electro-optical modulator, a mach-zehnder modulator, an IQ modulator, and a combination of electro-optical modulators.

7. The optical pulse train repetition frequency multiplication control device according to claim 6, wherein the combination of the electro-optical modulators is a combination of an optical intensity modulator and an optical phase modulator, wherein the optical intensity modulator comprises an electro-absorption modulator or a Mach-Zehnder modulator.

8. The optical pulse train repetition frequency multiplication control device according to claim 1, wherein the dispersion medium is one of a standard single mode fiber medium, a dispersion compensation fiber medium, or a chirped bragg grating medium.

9. An optical pulse train repetition frequency multiplication control method, characterized in that the optical pulse train repetition frequency multiplication control method comprises the steps of:

outputting an initial light pulse sequence according to a preset repetition frequency and a preset pulse width;

carrying out amplitude modulation on the initial optical pulse sequence to obtain an intermediate optical pulse sequence;

and inputting the intermediate optical pulse sequence into a dispersion medium with a dispersion value meeting the condition of the time domain Talbot effect so as to convert the intermediate optical pulse sequence into a target pulse sequence with the repetition frequency multiplication and output the target optical pulse sequence.

10. The optical pulse sequence repetition frequency multiplication control method according to claim 9, wherein the step of amplitude modulating the initial optical pulse sequence to obtain an intermediate optical pulse sequence comprises:

splitting the initial optical pulse train into a first optical pulse train and a second optical pulse train;

generating a clock signal corresponding to the first optical pulse sequence, and generating a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal;

and modulating the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain an intermediate optical pulse sequence.

11. The method according to claim 10, wherein the step of modulating the amplitude of the second optical pulse train according to the binary code modulation signal to obtain an intermediate optical pulse train further comprises:

and when the binary code modulation signal and the second optical pulse sequence are judged to be misaligned in the time domain according to the intermediate optical pulse sequence, adjusting the time delay of the second optical pulse sequence until the intermediate optical pulse sequence after the binary code modulation signal and the second optical pulse sequence are aligned in the time domain is generated.

Technical Field

The invention relates to the technical field of laser, in particular to a device and a method for controlling repetition frequency multiplication of an optical pulse sequence.

Background

The optical pulse sequence is widely applied to important fields of high-speed optical communication systems, optical signal processing, spectroscopy and the like. At present, there are various devices and methods for controlling the repetition frequency of an optical pulse train to achieve the generation of a high-speed optical pulse train. Mode-locked lasers are the most common pulsed laser sources, but due to the inherent cavity structure limitations, the range of re-frequency adjustment of the output optical pulse train is very limited. Commercial optical bit rate multipliers are often used for repetition frequency multiplication of high-speed optical pulse trains, but the multiplication factor is relatively fixed and the adjustment lacks flexibility, and the high-multiple multiplication of the repetition frequency of the optical pulse trains is difficult to realize.

The time domain Talbot effect is a self-imaging effect of an optical pulse sequence after passing through a dispersion medium with a specific dispersion value, and is often applied to the repetition frequency multiplication of the optical pulse sequence. Although the method has a simple structure, the change of the multiplication factor requires the adjustment of the dispersion value of the dispersion medium in a large range, thereby causing the repeated reconstruction of the whole system and severely limiting the flexibility of operation.

Disclosure of Invention

The invention aims to solve the technical problem that aiming at the defects of the prior art, the invention provides a device and a method for controlling the repetition frequency multiplication of an optical pulse sequence, and aims to realize the flexible adjustment of the repetition frequency multiplication control of the optical pulse sequence.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a pulsed laser source for generating an initial sequence of optical pulses having a preset repetition frequency and a preset pulse width;

the amplitude modulation module is connected with the pulse laser source and is used for modulating the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse sequence;

and the dispersion medium is used for providing a dispersion value meeting the time domain Talbot effect condition, is connected with the amplitude modulation module, and is used for converting the intermediate optical pulse sequence into a target optical pulse sequence with repetition frequency multiplication and outputting the target optical pulse sequence.

In one embodiment, an amplitude modulation module comprises:

the optical splitter is connected with the pulse laser source and is used for splitting the initial optical pulse sequence into a first optical pulse sequence and a second optical pulse sequence;

the photoelectric detector is connected with the optical splitter and used for generating a clock signal corresponding to the first optical pulse sequence;

the code pattern generator is connected with the photoelectric detector and used for generating a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal;

and the electro-optical modulator is respectively connected with the code pattern generator and the optical splitter and is used for modulating the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain an intermediate optical pulse sequence.

In one embodiment, the amplitude modulation module further comprises:

and the optical delay line is arranged between the optical splitter and the electro-optical modulator and used for adjusting the time delay of the second optical pulse sequence when the binary code modulation signal and the second optical pulse sequence are misaligned in the time domain, so that the second optical pulse sequence and the binary code modulation signal are aligned in the time domain.

In one embodiment, the optical pulse train repetition frequency multiplication control apparatus further includes:

and the optical amplifier is connected with the dispersion medium and used for adjusting the power of the target optical pulse sequence and outputting the adjusted target optical pulse sequence.

In one embodiment, the pulsed laser source is one of an active or passive mode-locked laser, a cavity-free pulsed laser source, and a micro-ring resonator.

In one embodiment, the electro-optic modulator is one of a single electro-optic modulator, a mach-zehnder modulator, an IQ modulator, or a combination of electro-optic modulators.

In one embodiment, the electro-optical modulator is combined into a light intensity modulator and an optical phase modulator combination, wherein the light intensity modulator comprises an electro-absorption modulator or a mach-zehnder modulator.

In one embodiment, the dispersion medium is one of a standard single mode fiber medium, a dispersion compensating fiber medium, or a chirped bragg grating medium.

In one embodiment, the step of the optical pulse sequence repetition frequency multiplication control method comprises the following steps:

outputting an initial light pulse sequence according to a preset repetition frequency and a preset pulse width;

carrying out amplitude modulation on the initial optical pulse sequence to obtain an intermediate optical pulse sequence;

and inputting the intermediate optical pulse sequence into a dispersion medium with a dispersion value meeting the condition of the time domain Talbot effect so as to convert the intermediate optical pulse sequence into a target pulse sequence with the repetition frequency multiplication and output the target optical pulse sequence.

In one embodiment, the step of amplitude modulating the initial optical pulse train to obtain an intermediate optical pulse train comprises:

splitting the initial optical pulse train into a first optical pulse train and a second optical pulse train;

generating a clock signal corresponding to the first optical pulse sequence, and generating a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal;

and modulating the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain an intermediate optical pulse sequence.

In one embodiment, after the step of modulating the amplitude of the second optical pulse train according to the binary code modulation signal to obtain an intermediate optical pulse train, the method further includes:

and when the binary code modulation signal and the second optical pulse sequence are judged to be misaligned in the time domain according to the intermediate optical pulse sequence, adjusting the time delay of the second optical pulse sequence until the intermediate optical pulse sequence after the binary code modulation signal and the second optical pulse sequence are aligned in the time domain is generated.

The invention relates to an optical pulse sequence repetition frequency multiplication control device, which can output an initial optical pulse sequence subjected to repetition frequency multiplication by setting a preset repetition frequency in a pulse laser source, an amplitude modulation module adjusts the amplitude in the initial optical pulse sequence to obtain an intermediate optical pulse sequence, a specific dispersion value is provided through a dispersion medium to enable the intermediate optical pulse sequence to generate a time domain Talbot effect, a target optical pulse sequence with smooth intensity and repetition frequency multiplication is obtained, and the flexible adjustment of the repetition frequency multiplication multiple is realized.

Drawings

Fig. 1 is a schematic structural diagram of a general embodiment of an optical pulse train repetition frequency multiplication control device according to the present invention;

FIG. 2 is a diagram of a pulse laser source without a cavity structure according to an alternative embodiment of the present invention;

FIG. 3 is a schematic view of an apparatus according to an alternative embodiment of the present invention;

FIG. 4 is a schematic view of a first apparatus according to a third alternative embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a second device according to a third alternative of the present invention;

FIG. 6 is a schematic structural view of a third device according to a third alternative of the present invention;

FIG. 7 is a schematic view of an alternative embodiment of the present invention;

FIG. 8 is a schematic flow chart of an embodiment of the method of the present invention;

FIG. 9 is a schematic diagram of an initial optical pulse train in accordance with the present invention;

FIG. 10 is a schematic diagram of an intermediate optical pulse train according to the present invention;

FIG. 11 is a schematic diagram of a target optical pulse train according to the present invention;

fig. 12 is a schematic diagram of a power amplified target optical pulse train according to the present invention.

The implementation, functional features and advantages of the present invention will be described with reference to the accompanying drawings.

Detailed Description

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

Referring to fig. 1, fig. 1 is a schematic structural diagram of an optical pulse sequence repetition frequency multiplication control apparatus according to an embodiment of the present invention, first, a repetition frequency and a pulse width, that is, a preset repetition frequency and a preset pulse width, are set in a pulse laser source 1, the pulse laser source 1 generates an optical pulse sequence with the preset repetition frequency and the preset pulse width, that is, an initial pulse sequence, and the pulse laser source 1 may be one of an active or passive mode-locked laser, a cavity-free pulse laser source, and a micro-ring resonator. The amplitude modulation module A receives the initial optical pulse sequence and adjusts the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse signal.

In some specific embodiments, the amplitude modulation a module includes an optical splitter 2, a photodetector 3, a pattern generator 4, and an electro-optical modulator 6, where the specific amplitude adjustment process of the initial optical pulse sequence includes that the optical splitter 2 is connected to the pulse laser source 1, and after receiving the initial optical pulse sequence output by the pulse laser source 1, the optical splitter 1 divides the initial optical pulse sequence into two optical pulse sequences, that is, a first optical pulse sequence and a second optical pulse sequence, where the first optical pulse sequence is input to the photodetector 3 connected to the optical splitter 2, and the second optical pulse sequence is input to the electro-optical modulator 6 connected to the optical splitter 2. The photodetector 3 converts the clock signal corresponding to the first optical pulse signal into a clock signal according to the first optical pulse sequence, and inputs the clock signal into a pattern generator 4 connected to the photodetector 3, and the pattern generator 4 generates a binary code modulation signal synchronized with the second optical pulse sequence according to the clock signal. The pattern generator is a signal output system that has a function of generating an analog signal or a digital signal of any form and is triggered by an external or internal clock. And the electro-optical modulator 6 is connected with the code pattern generator 4 and the optical splitter 2, and when the electro-optical modulator 6 receives the binary code modulation signal and the second optical pulse sequence, the electro-optical modulator 6 modulates the second optical pulse signal according to the binary code modulation signal to obtain an intermediate optical pulse signal. Each binary code modulation signal correspondingly controls one amplitude in the second optical pulse sequence, and the design of each binary code modulation signal reduces the requirement of the extinction ratio of the electro-optical modulator 6. The electro-optical modulator may be one of a single electro-optical modulator, a mach-zehnder modulator, an IQ (In-phase Quadrature) modulator, and a combination of electro-optical modulators, wherein the electro-optical modulator is a combination of an optical intensity modulator and an optical phase modulator, and the optical intensity modulator includes an electro-absorption modulator or a mach-zehnder modulator.

In other embodiments, in order to prevent misalignment between the binary code modulated signal and the second optical pulse sequence in the time domain, an optical delay line 5 is disposed between the optical splitter 2 and the electro-optical modulator 6, when the binary code modulated signal and the second optical pulse signal are judged to be misaligned in the time domain according to the intermediate optical pulse sequence, the optical delay line 5 precisely adjusts a time domain dislocation between the second optical pulse sequence and the binary code modulated signal so as to align the second optical pulse sequence and the binary code modulated signal in the time domain, and the electro-optical modulator 6 outputs the intermediate optical pulse sequence after the binary code modulated signal and the second optical pulse sequence are aligned in the time domain.

The amplitude modulation module A inputs the intermediate optical pulse sequence into the dispersion medium 7, the dispersion medium 7 provides a specific dispersion value to meet the time domain Talbot effect condition, and the dispersion medium 7 outputs the optical pulse sequence with flat intensity and repetition frequency multiplication, namely the target pulse sequence. The dispersion medium is one of standard single mode fiber medium, dispersion compensation fiber medium or chirped Bragg grating medium.

In other embodiments, the optical pulse sequence repetition frequency multiplication control device further comprises an optical amplifier 8, the optical amplifier 8 is connected with the dispersion medium 7, the dispersion medium 7 can input the target optical pulse sequence into the optical amplifier 8, and the optical amplifier 8 can increase the power of the target optical pulse sequence and output the target optical pulse sequence. The optical amplifier 8 may be any device or system having a laser power amplifying function, including but not limited to an optical fiber amplifier, a semiconductor optical amplifier, and the like.

The optical pulse sequence repetition frequency multiplication control device of the embodiment can output an initial optical pulse sequence with preset repetition frequency by setting the preset repetition frequency in the pulse laser source, the amplitude modulation module adjusts the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse sequence, a specific dispersion value is provided through a dispersion medium to enable the intermediate optical pulse sequence to generate a time domain Talbot effect, a target optical pulse sequence with flat intensity and repetition frequency multiplication is obtained, and the flexible adjustment of the repetition frequency multiplication multiple is realized.

The present embodiment also proposes alternatives, the first alternative:

selecting a pulse laser source without a cavity structure as the pulse laser source in fig. 1, and referring to fig. 2 for the structure of the pulse laser source without the cavity structure, wherein 101 is a tunable continuous laser source, 102 is an electro-optical modulator, 103 is an electrical signal amplifier, 104 is a sinusoidal signal source, 105 is a dispersive medium, 106 is an optical amplifier, 107 is a high nonlinear material, and 108 is an optical bandpass filter;

the alternative scheme II: selecting a delay adjustable code pattern generator to replace the code pattern generator 4 in fig. 1, referring to fig. 3, omitting an optical delay line, wherein the delay adjustable code pattern generator plays a role of adjusting time domain dislocation between a binary code modulation signal and a second optical pulse sequence;

the alternative scheme is three: selecting an IQ modulator as the electro-optical modulator 6 in fig. 1, see fig. 4, and it can be known from fig. 4 that the IQ modulator needs two binary code modulation signals; if the mach-zehnder modulator is selected as the electro-optical modulator 6, only one binary code is needed to modulate a signal, as shown in fig. 5; the combination of the electro-optical modulators is selected to be two electro-optical modulators, see fig. 6, 601 being the optical intensity modulator and 602 being the optical phase modulator.

The alternative scheme is four: referring to fig. 7, unlike the apparatus provided in the present embodiment, the optical splitter 2 and the photodetector 3 are omitted, the pulse laser source 1 is directly connected to the pattern generator 4, and the pattern generator is triggered by the internal clock of the pulse laser source to generate a binary code modulation signal synchronized with the optical pulse sequence.

An embodiment of an optical pulse train repetition frequency multiplication control method is provided, fig. 8 is a schematic flowchart of the optical pulse train repetition frequency multiplication control method, and the steps of the optical pulse train repetition frequency multiplication control method include:

step S10, outputting an initial optical pulse sequence according to a preset repetition frequency and a preset pulse width;

step S20, amplitude modulation is carried out on the initial optical pulse sequence to obtain an intermediate optical pulse sequence;

step S30, inputting the intermediate optical pulse sequence into a dispersion medium whose dispersion value satisfies the condition of time domain talbot effect, so as to convert the intermediate optical pulse sequence into a target optical pulse sequence with repetition frequency multiplication, and outputting the target optical pulse sequence.

The pulse laser source generates an initial optical pulse sequence according to a preset repetition frequency and a preset pulse width, the pulse laser source inputs the initial optical pulse sequence into an amplitude modulation module, the amplitude modulation module modulates the amplitude of the initial optical pulse sequence to obtain an intermediate optical pulse sequence, the amplitude modulation module inputs the intermediate optical pulse sequence into a dispersion medium, the dispersion medium provides a dispersion value to meet a time domain Talbot effect condition, and the intermediate optical pulse sequence is converted into a target optical pulse sequenceThe time-domain Talbot effect condition isβ₂Is the group velocity dispersion value of the dispersive medium and z is the length of the dispersive medium.

As shown in FIG. 9, the pulse width (pulse width) of the initial pulse width sequence output by the pulsed laser source is Δ T, and the repetition period is T₀Repetition frequency (repetition frequency) of f₀. The amplitude modulation module modulates the amplitude of the initial pulse sequence to obtain an intermediate optical pulse sequence, as shown in fig. 10, where N represents the total number of amplitude coefficients of the intermediate optical pulse sequence in one modulation period, and N also represents the multiple of repetition frequency, C_nDenotes the nth amplitude coefficient by | C_n|²Indicating the intensity of the nth light pulse. When the repetition multiplication factor N is 2, the amplitude in the intermediate optical pulse train is C_n＝1(n＝1，2)，C_n1 (n-3, 4) with a repetition period of 4T₀(ii) a When the repetition frequency multiplication multiple is greater than or equal to 3, the amplitude of the intermediate optical pulse sequence is C₁＝1，C_n2/(2-N) (N2, 3, …, N) with a repetition period NT₀. The intermediate optical pulse train shown in FIG. 10 was input to a dispersion medium to obtain the target optical pulse train shown in FIG. 11, whose repetition period was T₀N, pulse width Δ t, repetition frequency Nf₀The target optical pulse sequence is an optical pulse sequence with flat intensity and frequency doubling.

In some embodiments, the target optical pulse train is input to an optical amplifier and the power of the target optical pulse train is adjusted, for example, the medium target optical pulse train shown in fig. 11 is input to the optical amplifier, resulting in the optical pulse train shown in fig. 12.

In some embodiments, step S20 further includes:

step a, dividing the initial optical pulse sequence into a first optical pulse sequence and a second optical pulse sequence;

step b, generating a clock signal corresponding to the first optical pulse sequence, and generating a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal;

and c, modulating the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain an intermediate optical pulse sequence.

The initial optical pulse sequence enters the optical splitter and is divided into two paths, namely a first optical pulse sequence and a second optical pulse sequence, the first optical pulse sequence is input into the photoelectric detector, the photoelectric detector generates a clock signal corresponding to the first optical pulse sequence, the code pattern generator generates a binary code modulation signal synchronous with the second optical pulse sequence according to the clock signal, and the photoelectric modulator adjusts the amplitude of the second optical pulse sequence according to the binary code modulation signal to obtain a middle optical pulse sequence.

In some embodiments, after step c, further comprising:

and c1, when the binary code modulation signal and the second optical pulse sequence are judged to be misaligned in the time domain according to the intermediate optical pulse sequence, adjusting the time delay of the second optical pulse sequence until the intermediate optical pulse sequence after the binary code modulation signal and the second optical pulse sequence are aligned in the time domain is generated.

The intermediate optical pulse sequence may have a situation that the second optical pulse sequence and the binary code modulation signal are misaligned in the time domain, at this time, the optical delay line precisely adjusts time domain dislocations between the second optical pulse sequence and the binary code modulation signal, and the electro-optical modulator outputs the intermediate optical pulse sequence in which the second optical pulse sequence and the binary code modulation signal are aligned in the time domain.

In the embodiment, the initial optical pulse sequence is output according to the preset repetition frequency and the preset pulse width, the amplitude modulation is performed on the initial optical pulse sequence to obtain the intermediate optical pulse sequence, and then the intermediate optical pulse sequence is input into the dispersion medium to obtain the target optical pulse sequence with smooth intensity and repetition frequency multiplication, so that the flexible adjustment of the repetition frequency multiplication is realized.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.