CN105676560A

CN105676560A - Controllable full-light optical random logic gate

Info

Publication number: CN105676560A
Application number: CN201610170114.XA
Authority: CN
Inventors: 钟东洲; 许葛亮; 罗伟
Original assignee: Wuyi University Fujian
Current assignee: Wuyi University Fujian
Priority date: 2016-03-22
Filing date: 2016-03-22
Publication date: 2016-06-15
Anticipated expiration: 2036-03-22
Also published as: CN105676560B

Abstract

The present invention relates to a photonic device, specifically a controllable all-optical random logic gate, including a tunable continuous laser, a first optical isolator, an optical attenuator, a beam splitter, a main vertical cavity surface emitting laser, a second optical isolator, The first polarizing beam splitter, the periodic pole lithium niobate crystal, the third optical isolator, the second polarizing beam splitter, the third polarizing beam splitter, the optical amplifier, the surface emitting laser from the vertical cavity, the fourth polarizing beam splitting A first plane mirror, a first half-wave plate and a second half-wave plate are connected in parallel between the beam splitter and the main vertical cavity surface-emitting laser; there is also a first polarizing beam splitter and a periodic polar lithium niobate crystal A second plane mirror, a first Faraday rotator, and a third half-wave plate are connected in parallel; a fourth half-wave plate and a second Faraday rotator are also connected in parallel between the second polarizing beam splitter and the third polarizing beam splitter; periodic A transverse electric field E ₀ is applied to the lithium niobate crystal. The logic gate realizes all-optical random logic gate operation and delay storage.

Description

Controllable all-optical random logic gate

技术领域technical field

本发明涉及光子设备，具体为可控的全光随机逻辑门。The invention relates to a photonic device, in particular to a controllable all-optical random logic gate.

背景技术Background technique

由于垂直腔半导体激光器(VCSEL)的有源腔为对称的圆柱形，它比较容易激射两个线性偏振光。当光的偏振方向沿有源腔的坐标轴的X轴方向时称为X偏振光，偏振方向沿Y轴的光Y轴称为Y偏振光，且X偏振光与Y偏振光相互垂直。改变泵浦电流、注入能量，或者改变失谐的注入光能导致偏振转换和偏振双稳态的产生。在最近相关的报道中，使用光注入激光器中的偏振转换和偏振双稳态，不同类型的光电逻辑门以及全光逻辑门运算可以被获得。例如，在自由运行的VCSEL系统中，逻辑输入通过泵浦电流来编译，逻辑输出通过VCSEL发射的两线性偏振光来解码，可以得到随机逻辑“或”门，“或非”门以及“与非”门；在相干光注入VCSEL中，逻辑输入通过注入光强来编译，逻辑输出通过VCSEL发射的两线性偏振光来解码，可以获得逻辑“与”门和“或”门；在可调谐光注入VCSEL中，逻辑输入通过外部光频率失谐来编译，逻辑输出通过激光器输出的两线性偏振光来解码，可以实现全光随机逻辑“或”门。然而，在上述的方法中，一些重要的参数(如泵浦电流，光注入能量和失谐的注入光)的轻微变化会改变输出偏振的状态。同时，由于偏振转换的不稳定，导致了在上述方法中的逻辑门有很差的稳定性。另外，由于全光数字逻辑信号在延时存储方面存在一定的技术困难，因此，上述的基本的逻辑门运算只能应用于组合逻辑光子设备，但是不能推广应用于时序逻辑光子设备。Since the active cavity of a vertical cavity semiconductor laser (VCSEL) is a symmetrical cylinder, it is relatively easy to excite two linearly polarized lights. When the polarization direction of the light is along the X-axis direction of the coordinate axis of the active cavity, it is called X-polarized light, and the light whose polarization direction is along the Y-axis Y-axis is called Y-polarized light, and the X-polarized light and Y-polarized light are perpendicular to each other. Changing the pump current, injecting energy, or changing the detuned injected light energy results in polarization switching and polarization bistability. In related recent reports, different types of optoelectronic logic gates as well as all-optical logic gate operations can be obtained using polarization switching and polarization bistability in light injection lasers. For example, in a free-running VCSEL system, the logic input is coded by pumping current, and the logic output is decoded by two linearly polarized light emitted by the VCSEL, resulting in random logic OR gates, NOR gates, and NAND gates. "gate; in the coherent optical injection VCSEL, the logic input is compiled by the intensity of the injected light, and the logic output is decoded by the two linearly polarized lights emitted by the VCSEL, and the logic "AND" gate and "OR" gate can be obtained; in the tunable optical injection In the VCSEL, the logic input is compiled through external optical frequency detuning, and the logic output is decoded through the two linearly polarized lights output by the laser, which can realize an all-optical random logic "OR" gate. However, in the aforementioned methods, slight changes in some important parameters (such as pump current, optical injection energy, and detuned injected light) will change the state of the output polarization. At the same time, the logic gates in the above method have poor stability due to the instability of the polarization conversion. In addition, because all-optical digital logic signals have certain technical difficulties in delayed storage, the above-mentioned basic logic gate operations can only be applied to combinatorial logic photonic devices, but cannot be applied to sequential logic photonic devices.

发明内容Contents of the invention

针对上述技术问题，本发明提供一种可控的全光随机逻辑门，通过控制外加电场与两逻辑输入的逻辑关系，可以实现可控的不全光随机逻辑门，如“非”门、“与”门、“与非”门、“或”门、“异或”门、“或非”门、“异或非”门运算及其延时存储。In view of the above technical problems, the present invention provides a controllable all-optical random logic gate, by controlling the logical relationship between the applied electric field and the two logic inputs, a controllable non-optical random logic gate, such as "NOT" gate, "AND " gate, "NAND" gate, "OR" gate, "XOR" gate, "NOR" gate, "XNOR" gate operation and its delay storage.

本发明通过如下技术方案实现：The present invention realizes through following technical scheme:

可控的全光随机逻辑门，依次包括：可调谐连续激光器、第一光隔离器、光学衰减器、分束器、主垂直腔表面发射激光器、第二光隔离器、第一偏振分束器、周期性极铌酸锂晶体、第三光隔离器、第二偏振分束器、第三偏振分束器、光学放大器、从垂直腔表面发射激光器、第四偏振分束器；Controllable all-optical random logic gates, in sequence: tunable CW laser, first optical isolator, optical attenuator, beam splitter, main vertical cavity surface emitting laser, second optical isolator, first polarizing beam splitter , Periodic polar lithium niobate crystal, third optical isolator, second polarizing beam splitter, third polarizing beam splitter, optical amplifier, vertical cavity surface emitting laser, fourth polarizing beam splitter;

所述的分束器和主垂直腔表面发射激光器之间还并联有第一平面镜、第一半波片和第二半波片；A first plane mirror, a first half-wave plate and a second half-wave plate are also connected in parallel between the beam splitter and the main VCSEL;

所述的第一偏振分束器与周期性极铌酸锂晶体之间还并联有第二平面镜、第一法拉第旋转器、第三半波片；A second plane mirror, a first Faraday rotator, and a third half-wave plate are also connected in parallel between the first polarizing beam splitter and the periodic polar lithium niobate crystal;

所述的第二偏振分束器与第三偏振分束器之间还并联有第四半波片、第二法拉第旋转器；A fourth half-wave plate and a second Faraday rotator are also connected in parallel between the second polarization beam splitter and the third polarization beam splitter;

周期性极铌酸锂晶体上加有横向电场E₀。A transverse electric field E ₀ is applied to the periodic polar lithium niobate crystal.

本发明提供的可控的全光随机逻辑门，实现了全光随机逻辑门运算及其延时存储，具体能够实现“非”门、“与”门、“与非”门、“或”门、“异或”门、“或非”门、“异或非”门运算及其延时存储。该可控的全光随机逻辑门的运算速度比电光逻辑门的运算速度要快，而且这些装置可以推广应用于时序光子逻辑设备。The controllable all-optical random logic gate provided by the present invention realizes all-optical random logic gate operation and its delay storage, and can specifically realize "NOT" gate, "AND" gate, "AND-NOT" gate, and "OR" gate , "Exclusive OR" gate, "NOR" gate, "Exclusive OR" gate operation and its delay storage. The operation speed of the controllable all-optical random logic gate is faster than that of the electro-optic logic gate, and these devices can be popularized and applied to sequential photonic logic devices.

附图说明Description of drawings

图1为本发明的结构示意图；Fig. 1 is a structural representation of the present invention;

图2为实施例在不同外加电场的作用下偏振双稳态滞后回归线；Fig. 2 is the polarization bistability hysteresis regression line of the embodiment under the effect of different applied electric fields;

图3为实施例逻辑“非”门、“异或”门、“异或非”门运算及其延时存储；Fig. 3 is embodiment logical " NOT " gate, " exclusive OR " gate, " exclusive OR NOT " gate operation and delay storage thereof;

图4为实施例罗辑“与”门、“与非”门、“或”门和“或非”门运算及其延时存储。Fig. 4 is the logic "AND" gate, "NAND" gate, "OR" gate and "NOR" gate operation and its delay storage in the embodiment.

具体实施方式detailed description

以下结合附图对本发明内容做进一步说明：Below in conjunction with accompanying drawing, content of the present invention will be further described:

如图1所示，可控的全光随机逻辑门，依次包括：可调谐连续激光器1、第一光隔离器2、光学衰减器3、分束器4、主垂直腔表面发射激光器5、第二光隔离器6、第一偏振分束器7、周期性极铌酸锂晶体8、第三光隔离器9、第二偏振分束器10、第三偏振分束器11、光学放大器12、从垂直腔表面发射激光器13、第四偏振分束器14；As shown in Fig. 1, the controllable all-optical random logic gate sequentially includes: a tunable continuous laser 1, a first optical isolator 2, an optical attenuator 3, a beam splitter 4, a main vertical cavity surface emitting laser 5, a second Two optical isolators 6, a first polarizing beam splitter 7, a periodic polar lithium niobate crystal 8, a third optical isolator 9, a second polarizing beam splitter 10, a third polarizing beam splitter 11, an optical amplifier 12, From a vertical cavity surface emitting laser 13, a fourth polarizing beam splitter 14;

所述的分束器4和主垂直腔表面发射激光器5之间还并联有第一平面镜15、第一半波片16和第二半波片17；A first plane mirror 15, a first half-wave plate 16 and a second half-wave plate 17 are also connected in parallel between the beam splitter 4 and the main VCSEL 5;

所述的第一偏振分束器7与周期性极铌酸锂晶体8之间还并联有第二平面镜18、第一法拉第旋转器19、第三半波片20；A second plane mirror 18, a first Faraday rotator 19, and a third half-wave plate 20 are also connected in parallel between the first polarizing beam splitter 7 and the periodic polar lithium niobate crystal 8;

所述的第二偏振分束器10与第三偏振分束器11之间还并联有第四半波片21、第二法拉第旋转器22；A fourth half-wave plate 21 and a second Faraday rotator 22 are connected in parallel between the second polarization beam splitter 10 and the third polarization beam splitter 11;

周期性极铌酸锂晶体8上加有横向电场E₀23。A transverse electric field E ₀ 23 is applied to the periodic polar lithium niobate crystal 8 .

工作原理：working principle:

主垂直腔表面发射激光器5和从垂直腔表面发射激光器13的工作波长均为850nm，阈值电流为6.8mA，其温度精确控制在±0.01℃。第一光隔离器2的作用是确保可调谐连续激光器1发出的光单向注入主垂直腔表面发射激光器5。第二光隔离器6的作用是避免从第一偏振分束器7的光反馈注入到主垂直腔表面发射激光器5。第三光隔离器9保证从周期性极铌酸锂晶体8输出的光单向注入到从垂直腔表面发射激光器13。放置在可调谐连续激光器1右边的光学衰减器3用来调谐光注入的能量。放在从垂直腔表面发射激光器13的左边光学放大器12是增强从垂直腔表面发射激光器13的注入光强。外加的横向电场E₀23沿着周期性极铌酸锂晶体8坐标系的x轴方向。可调谐连续激光器1发出x偏振光，其被分离成两束光，一束直接注入到主垂直腔表面发射激光器5中，另一束被第一半波片16和第二半波片17转化成e偏振光，再注入到主垂直腔表面发射激光器5中。固定一定的泵浦电流，主垂直腔表面发射激光器5激射x偏振光和y偏振光，它们被第一偏振分束器7分离。从第一偏振分束器7分离的x偏振光被认为是周期性极铌酸锂晶体8中0光的初始输入，因为它是沿着0光的偏振方向。当通过第一法拉第旋转器19和第三半波片20，使从第一偏振分束器7分离的y偏振光与e光的偏振方向平行时，它考虑为周期性极铌酸锂晶体8中e光的初始输入。在外加横向电场E₀23的作用下，x和y偏振光在周期性极铌酸锂晶体8中经历电光幅度调制。从周期性极铌酸锂晶体8输出0光，在延迟时间T后，作为x偏振光，通过第三偏振分束器11和光学放大器12后，注入到从垂直腔表面发射激光器13。并且它被考虑为逻辑输出X₁。输出e光，首先通过延时T后，再通过第四半波片21和第二法拉第旋转器22。这时，它的偏振方向沿着y偏振方向。在这种条件下，它作为y偏振光，通过第三偏振分束器11和光学放大器12后，注入到从垂直腔表面发射激光器13。另外，它被定义为逻辑输出Y₁。从垂直腔表面发射激光器13输出的x偏振光和y偏振光分别考虑为逻辑输出X₂和Y₂。Both the main VCSEL 5 and the slave VCSEL 13 have an operating wavelength of 850nm, a threshold current of 6.8mA, and their temperatures are precisely controlled at ±0.01°C. The function of the first optical isolator 2 is to ensure that the light emitted by the tunable CW laser 1 is unidirectionally injected into the main VCSEL 5 . The function of the second optical isolator 6 is to prevent the optical feedback from the first polarizing beam splitter 7 from being injected into the main VCSEL 5 . The third optical isolator 9 ensures that the light output from the periodic polar lithium niobate crystal 8 is unidirectionally injected into the vertical cavity surface emitting laser 13 . The optical attenuator 3 placed on the right side of the tunable continuous laser 1 is used to tune the energy of the light injection. The optical amplifier 12 placed on the left side of the vertical cavity surface emitting laser 13 is to enhance the injection light intensity from the vertical cavity surface emitting laser 13 . The applied transverse electric field E ₀ 23 is along the x-axis direction of the periodic polar lithium niobate crystal 8 coordinate system. The tunable CW laser 1 emits x-polarized light, which is split into two beams, one beam is directly injected into the main VCSEL 5, and the other beam is converted by the first half-wave plate 16 and the second half-wave plate 17 into e-polarized light, and then injected into the main vertical cavity surface emitting laser 5. With a certain pumping current fixed, the main VCSEL 5 excites x-polarized light and y-polarized light, which are separated by the first polarization beam splitter 7 . The x-polarized light separated from the first polarizing beam splitter 7 is considered as the initial input of the zero light in the periodic polar lithium niobate crystal 8 because it is along the polarization direction of the zero light. When the y-polarized light separated from the first polarizing beam splitter 7 is parallel to the polarization direction of the e light through the first Faraday rotator 19 and the third half-wave plate 20, it is considered as a periodic polar lithium niobate crystal 8 The initial input of e-light in the middle. Under the action of the external transverse electric field E ₀ 23 , the x- and y-polarized light undergoes electro-optic amplitude modulation in the periodic polar lithium niobate crystal 8 . 0 light is output from the periodic polar lithium niobate crystal 8, after a delay time T, it is used as x-polarized light, and after passing through the third polarizing beam splitter 11 and the optical amplifier 12, it is injected into the vertical cavity surface emitting laser 13. And it is considered as logic output X ₁ . The output e light first passes through the time delay T, and then passes through the fourth half-wave plate 21 and the second Faraday rotator 22 . At this time, its polarization direction is along the y polarization direction. Under this condition, it passes through the third polarizing beam splitter 11 and the optical amplifier 12 as y-polarized light, and injects it into the surface emitting laser 13 from the vertical cavity. Additionally, it is defined as logic output Y ₁ . The x-polarized light and y-polarized light output from the vertical cavity surface emitting laser ₁₃ are considered as logical outputs X2 and _Y2 , respectively.

激光器的一些重要参数如下：主垂直腔表面发射激光器5与从垂直腔表面发射激光器13有相同的泵浦电流，即μ_M＝μ_S＝1.2；主垂直腔表面发射激光器5的X偏振和Y偏振的注入光强度：K_Mx＝K_My＝10ns^-1；从激光器的X偏振和Y偏振的注入光强度：K_Sx＝K_Sy＝5K_Mx；外部光振幅：E_inj＝0.6。这里，假设频率失谐值Δω＝dω₁+dω₂(dω₁，dω₂均为方波)，并且用来编译成两个逻辑输入。针对频率失谐dω₁，逻辑输入定义为A₁；针对失谐dω₂，逻辑输入定义为A₂。在这个条件下，逻辑输入有四个序列：(0，0)，(0，1)，(1，0)和(1，1)。对于(0，1)和(1，0)，有相同的频率失谐Δω_∏。因此，四个逻辑输入序列可以用三个标准频率失谐(Δω_I，Δω_∏，Δω_III)来编译，这里，代表(0，0)，代表(1，1)。对于逻辑非门设计，逻辑输入A₁用频率失谐dω₁来编译。假定当dω₁＝75GHz时，A₁＝1；假如dω₁＝-140GHz，A₂＝0。对于其它逻辑门，Δω_∏被设定为-65radGHz，考虑为215radGHz。逻辑输出解码如下：周期性极铌酸锂晶体8只输出X偏振光，记X₁＝1，Y₁＝0，输出Y偏振光，则X₁＝0，Y₁＝1；从VCSEL只输出X偏振光，X₂＝1，Y₂＝0，若从垂直腔表面发射激光器13输出Y偏振光，则X₂＝0，Y₂＝1。Some important parameters of the laser are as follows: the main VCSEL 5 has the same pumping current as the slave VCSEL 13, namely μ _M = μ _S = 1.2; the X polarization and Y of the main VCSEL 5 Polarized injected light intensity: K _Mx =K _My =10 ns ^-1 ; X-polarized and Y-polarized injected light intensity from the laser: K _Sx =K _Sy =5K _Mx ; external light amplitude: E _inj =0.6. Here, it is assumed that the frequency detuning value Δω=dω ₁ +dω ₂ (dω ₁ , dω ₂ are both square waves), and is used to compile into two logic inputs. For frequency detuning dω ₁ , the logic input is defined as A ₁ ; for detuning dω ₂ , the logic input is defined as A ₂ . In this condition, the logical input has four sequences: (0,0), (0,1), (1,0) and (1,1). For (0,1) and (1,0), there is the same frequency detuning Δω _Π . Therefore, four logical input sequences can be compiled with three standard frequency detunings (Δω _I , Δω _∏ , Δω _III ), here, stands for (0, 0), stands for (1, 1). For _a NOT gate design, the logic input A1 is compiled with frequency detuning _dω1 . Assume that when dω ₁ =75GHz, A ₁ =1; if dω ₁ =-140GHz, A ₂ =0. For other logic gates, Δω _∏ is set to -65radGHz, Consider 215radGHz. The logic output is decoded as follows: 8 periodic polar lithium niobate crystals only output X polarized light, record X ₁ =1, Y ₁ =0, output Y polarized light, then X ₁ =0, Y ₁ =1; only output from VCSEL For X polarized light, X ₂ =1, Y ₂ =0, if the VCSEL 13 outputs Y polarized light, then X ₂ =0, Y ₂ =1.

基于众所周知的垂直腔表面发射激光器的自旋反转模型，考虑外部光注入，得到主垂直腔表面发射激光器的速率方程组如下：Based on the well-known spin-inversion model of VCSELs and considering external light injection, the rate equations for the main VCSEL are obtained as follows:

$\begin{matrix} \frac{{dE E}_{Mx Mx} ((t t))}{dt dt} = = k k ((11 + + ia ia)) [[{N N}_{M m} ((t t)) {E E.}_{Mx Mx} ((t t)) + + {in in}_{M m} ((t t)) {E E.}_{My My} ((t t)) - - {E E.}_{Mx Mx} ((t t))]] - - i i (({γ γ}_{p p} + + Δω Δω)) {E E.}_{Mx Mx} \\ - - {γ γ}_{a a} {E E.}_{MX MX} + + \sqrt{{β β}_{sp sp} {γ γ}_{e e} {N N}_{M m}} {ξ ξ}_{x x} + + {K K}_{Mx Mx} {E E.}_{inj inj},, \end{matrix} - - - - - - ((11))$

$\begin{matrix} \frac{{dE E}_{My My} ((t t))}{dt dt} = = k k ((11 + + ia ia)) [[{N N}_{M m} ((t t)) {E E.}_{My My} ((t t)) - - {in in}_{M m} ((t t)) {E E.}_{Mx Mx} ((t t)) - - {E E.}_{My My} ((t t))]] - - i i (({γ γ}_{p p} + + Δω Δω)) {E E.}_{Mx Mx} \\ + + {γ γ}_{a a} {E E.}_{My My} + + \sqrt{{β β}_{sp sp} {γ γ}_{e e} {N N}_{M m}} {ξ ξ}_{y the y} + + {K K}_{My My} {E E.}_{inj inj},, \end{matrix} - - - - - - ((22))$

$\frac{{dN dN}_{M m} ((t t))}{dt dt} = = - - {γ γ}_{e e} [[{N N}_{M m} ((11 + + {| | {E E.}_{Mx Mx} | |}^{22} + + {| | {E E.}_{My My} | |}^{22}))]] + + {γ γ}_{e e} {μ μ}_{M m} - - {iγ iγ}_{e e} {n no}_{M m} (({E E.}_{My My} {E E.}_{Mx Mx}^{* *} - - {E E.}_{Mx Mx} {E E.}_{My My}^{* *})),, - - - - - - ((33))$

$\frac{{dn dn}_{M m} ((t t))}{dt dt} = = - - {γ γ}_{s the s} {n no}_{M m} - - {γ γ}_{e e} {n no}_{M m} (({| | {E E.}_{Mx Mx} | |}^{22} + + {| | {E E.}_{My My} | |}^{22})) - - {iγ iγ}_{e e} {N N}_{M m} (({E E.}_{My My} {E E.}_{Mx Mx}^{* *} - - {E E.}_{Mx Mx} {E E.}_{My My}^{* *})),, - - - - - - ((44))$

这里，下标M指的是主垂直腔表面发射激光器，下标x和y分别表示xandy线性偏振分量；E是慢变振幅；N是在介带和导带之间的反转粒子数；N为上旋和下旋辐射载流子数差；k是场损耗速率；γ_e是N的衰减速率；γ_s是自旋反转弛豫速率；a线宽增强因子；γ_a和γ_p分别表示各向异性光场振幅损耗速率和有源介质线性双折射效应；μ_M主垂直腔表面发射激光器的归一化泵浦电流；噪声强度参量D定义为β_sp是自发辐射因子；ξ_x和ξ_y分别为两个高斯噪声，他们的时间关系是<ξ_i(t)ξ_j ^*(t)>＝2δ_ijδ(t-t’).K_Mx(K_My)是x(y)偏振分量注入强度；E_inj是注入光场振幅；注入光场失谐ω_inj是注入光场的角频率；参考频率定义为(ω_x+ω_y)/2，ω_xa和分别是独立运行垂直腔表面发射激光器的x和y偏振分量的角频率。Here, the subscript M refers to the main vertical cavity surface emitting laser, and the subscripts x and y represent the xandy linear polarization component, respectively; E is the slowly varying amplitude; N is the number of inversion particles between the medium band and the conduction band; N is the difference between up-spin and down-spin radiation carriers; _k is the field loss rate; γ _e is the decay rate of N; γ _s is the spin inversion relaxation rate; _a linewidth enhancement factor; Represents the anisotropic optical field amplitude loss rate and the linear birefringence effect of the active medium; the normalized pump current of the _μM main vertical cavity surface emitting laser; the noise intensity parameter D is defined as β _sp is the spontaneous emission factor; ξ _x and ξ _y are two Gaussian noises respectively, and their time relationship is <ξ _i (t)ξ _j ^* (t)>=2δ _ij δ(t-t').K _Mx (K _My ) is the injection intensity of the x(y) polarization component; E _inj is the amplitude of the injection light field; the detuning of the injection light field ω _inj is the angular frequency of the injected light field; the reference frequency Defined as (ω _x +ω _y )/2, ω _x a and are the angular frequencies of the x- and y-polarized components of a vertical-cavity surface-emitting laser operating independently, respectively.

如图1所示，x偏振分量沿周期性极化铌酸锂晶体o光方向传播，y偏振分量通过第一法拉第旋转器19和第一半波片16与e光平行。在这些条件下，x和y偏振分量考虑为晶体的o光和e光初始输入。因此有As shown in FIG. 1 , the x-polarized component propagates along the o-light direction of the periodically polarized lithium niobate crystal, and the y-polarized component passes through the first Faraday rotator 19 and the first half-wave plate 16 parallel to the e-light. Under these conditions, the x and y polarization components are considered as the initial input of o-light and e-light to the crystal. Therefore there are

这里，U_x和U_y分别表示o光和e光振幅；是Planck常数；S_A是光斑的有效面积；V是垂直腔表面发射激光器有源层体积；υ_c为真空中的光速；T_L＝2n_gυ_c/L_v是光在激光腔内一次循环时间；ω₀是从主垂直腔半导体激光器发射激光脉冲的中心频率；n₁和n₂分别是o光和e光的未扰动的折射率。由于相位失配，二阶非线性效应非常弱。因此，两线性偏振分量在周期性极铌酸锂晶体8中的线性电光效应耦合波方程的解析解为：Here, U _x and U _y represent the o-light and e-light amplitudes, respectively; is the _Planck constant; _S _A is the effective area of the spot; _V is the volume of the active layer of the vertical cavity surface emitting laser; _υ _c is the speed of light in vacuum; time; _ω0 is the center frequency of the laser pulse emitted from the main vertical cavity semiconductor laser; _n1 and _n2 are the unperturbed refractive indices of o-light and e-light, respectively. Due to the phase mismatch, the second-order nonlinear effects are very weak. Therefore, the analytical solution of the coupled wave equation for the linear electro-optic effect of the two linearly polarized components in the periodic polar lithium niobate crystal 8 is:

U_x，y(L，t)＝ρ_x，y(L，t)exp(iβ₀L)exp[iφ_x，y(L，t)](6)U _{x, y} (L, t) = ρ _{x, y} (L, t) exp(iβ ₀ L) exp[iφ _{x, y} (L, t)] (6)

这里：here:

${φ φ}_{x x,, y the y} ((L L,, t t)) = = {tan the tan}^{- - 11} [[\frac{&PlusMinus; &PlusMinus; {γU γU}_{x x,, y the y} ((00,, t t)) - - {d d}_{1,3 1,3} {U u}_{y the y,, x x} ((00,, t t))}{ν ν {U u}_{x x,, y the y} ((00,, t t))} tan the tan ((νL νL))]],, - - - - - - ((88))$

并且：and:

${β β}_{00} = = \frac{Δk Δk - - {d d}_{22} - - {d d}_{44}}{22},, - - - - - - ((99))$

$ν ν = = \sqrt{\frac{{((Δk Δk + + {d d}_{22} - - {d d}_{44}))}^{22} + + 44 {d d}_{11} {d d}_{33}}{22}},, - - - - - - ((1010))$

$γ γ = = \frac{{d d}_{44} - - {d d}_{22} - - Δk Δk}{22},, - - - - - - ((1111))$

这里，系数d₁，d₂，d₃和d₄详见参考文献：J.Zamora-Munt，andC.Masoller，“NumericalimplementationofaVCSEL-basedstochasticlogicgateviapolarizationbistability，”OptExpress18(16)，16418-16429(2010)；L是晶体长度；波矢失配Δk＝k_x-k_y+K₁，K₁＝2π/Λ是晶体的第一阶倒格矢，Λ是极化周期，k_x和k_y分别表示x和y偏振分量在中心频率处的波矢。这里，考虑K₁接近波矢失配量k_x-k_y，由于相位失配，忽略哪些对线性电光效应无影响的分量。Here, the coefficients d ₁ , d ₂ , d ₃ and d ₄ are detailed in references: J.Zamora-Munt, and C.Masoller, "Numerical implementation of a VCSEL-based stochastic logic gate via polarization bistability," OptExpress18(16), 16418-16429(2010); L is the crystal Length; wavevector mismatch Δk=k _x _-ky +K ₁ , K ₁ =2π/Λ is the first-order reciprocal lattice vector of the crystal, Λ is the polarization period, k _x and ky represent x and _y polarization respectively The wave vector of the component at the center frequency. Here, considering that K ₁ is close to the wave vector mismatch k _x _-ky , due to the phase mismatch, those components that have no influence on the linear electro-optic effect are ignored.

当两个经历线性电光调制的偏振分量首先延时τ，然后注入到从垂直腔表面发射激光器时，有：When the two polarization components undergoing linear electro-optic modulation are first delayed by τ and then injected into a surface emitting laser from a vertical cavity, we have:

其中，E_px和E_py分别为经历电光调制的x和y偏振分量的振幅。在这个条件下，延时光注入的从垂直腔表面发射激光器的速率方程组被描述为：where _Epx and _Epy are the amplitudes of the x- and y-polarized components undergoing electro-optic modulation, respectively. Under this condition, the rate equations for delayed light injection from a VCSEL are described as:

$\begin{matrix} \frac{d d {N N}_{S S} ((t t))}{dt dt} = = - - {γ γ}_{e e} {{{N N}_{S S} ((t t)) - - {μ μ}_{S S} + + {N N}_{S S} ((t t)) (({| | {E E.}_{Sx S x} ((t t)) | |}^{22} + + {| | {E E.}_{Sy Sy} | |}^{22})) \\ + + {in in}_{S S} ((t t)) [[{E E.}_{Sy Sy} ((t t)) {E E.}^{* *}_{Sx S x} ((t t)) - - {E E.}_{Sx S x} ((t t)) {E E.}^{* *}_{Sy Sy} ((t t))}},, \end{matrix} - - - - - - ((1414))$

$\begin{matrix} \frac{d d {N N}_{S S} ((t t))}{dt dt} = = - - {γ γ}_{s the s} {n no}_{S S} ((t t)) - - {γ γ}_{e e} {{{n no}_{S S} ((t t)) (({| | {E E.}_{Sx S x} ((t t)) | |}^{22} + + {| | {E E.}_{Sy Sy} | |}^{22})) \\ + + {iN i}_{S S} ((t t)) [[{E E.}_{Sy Sy} ((t t)) {E E.}^{* *}_{Sx S x} ((t t)) - - {E E.}_{Sx S x} ((t t)) {E E.}^{* *}_{Sy Sy} ((t t))}},, \end{matrix} - - - - - - ((1515))$

这里下标S指的是从垂直腔表面发射激光器；是主和从垂直腔表面发射激光器之间的中心频率失谐；K_Sx(K_Sy)是x(y)偏振分量注入强度；μ_S是归一化泵浦电流。Here the subscript S refers to the laser emitting from the vertical cavity surface; is the center frequency detuning between the main and slave VCSELs; K _Sx (K _Sy ) is the x(y) polarization component injection intensity; μ _S is the normalized pump current.

从图1可以看见，当从垂直腔表面发射激光器受到来自于周期性极化铌酸锂晶体输出光强注入时，从垂直腔表面发射激光器发射的x(y)偏振分量与带有延时注入光中的x(y)偏振分量有广义混沌同步，即It can be seen from Figure 1 that when the vertical cavity surface emitting laser is injected with the output light intensity from the periodically poled lithium niobate crystal, the x (y) polarization component emitted from the vertical cavity surface emitting laser is consistent with the delayed injection The x(y) polarization components in light have generalized chaotic synchronization, namely

I_Sx(t)≈C₁I_Px(t-τ)(16)I _Sx (t)≈C ₁ I _Px (t-τ)(16)

I_Sy(t)≈C₂I_Py(t-τ)(17)I _Sy (t)≈C ₂ I _Py (t-τ)(17)

如图2给出了针对外加电场E₀＝0kV/mm和E₀＝85kV/mm，偏振双稳态滞后回归线，这个双稳态曲线是频率失谐与两线性偏振光强之间的函数。其中，点线表示为X偏振光，实线为Y偏振光。轨迹(a)和(b)表示在两个不同外加电场作用下，PPLN晶体输出的偏振双稳态环；轨迹(c)和(d)表示在两个不同外加电场作用下，从VCSEL输出的偏振双稳态环。箭头所示的三个频率失谐dω用来编译逻辑输入。Fig. 2 shows the hysteresis regression line of the polarization bistable state for the applied electric fields E ₀ =0kV/mm and E ₀ =85kV/mm, and this bistable state curve is a function between the frequency detuning and the light intensity of the two linear polarizations. Wherein, the dotted line represents X polarized light, and the solid line represents Y polarized light. Trajectories (a) and (b) represent the polarization bistable rings output from the PPLN crystal under two different applied electric fields; traces (c) and (d) represent the output from the VCSEL under two different applied electric fields Polarized bistable rings. The three frequency detuning dω indicated by the arrows are used to code the logic input.

表1给出了逻辑非运算的输入与输出的逻辑关系，以及外加电场与逻辑输入的逻辑关系。逻辑输入用频率失谐dω₁来编译，其定义为A₁。外加电场逻辑符号用e来表示。当逻辑信号e为“0”时，表示外加电场E₀为0kV/mm，当它为1时，外加电场E₀为85kV/mm；当逻辑信号e与逻辑输入A2相同时，由表1可知： $Y_{1} = \overset{&OverBar;}{A_{1}}, Y_{2} = \overset{&OverBar;}{A_{2}} .$ Table 1 shows the logic relationship between the input and output of the logic NOT operation, and the logic relationship between the external electric field and the logic input. The logic input is coded with a frequency detuning dω ₁ defined as A ₁ . The logical symbol of the applied electric field is represented by e. When the logic signal e is " ₀ ", it means that the applied electric field E0 is 0kV/mm; when it is 1, the applied electric field E0 is _85kV /mm; when the logic signal e is the same as the logic input A2, it can be seen from Table 1 : $Y_{1} = \overset{&OverBar;}{A_{1}}, Y_{2} = \overset{&OverBar;}{A_{2}} .$

表1Table 1

表2给出了逻辑异或，以及异或非运算的输入与输出的逻辑关系，以及外加电场与逻辑输入的逻辑关系。逻辑输入用三个标准频率失谐(Δω_I，Δω_∏，Δω_III)来编译，逻辑输出X₁和Y₁通过PPLN输出的一定比例和延时两线性偏振光强来解码，逻辑输出X₂和Y₂通过从VCSEL输出的两线性偏振光强来解码。由表2可知：Y₁＝A1⊙A2，Y₂＝A1⊙A2。Table 2 shows the logic relationship between logic XOR and XOR operation input and output, and the logic relationship between external electric field and logic input. The logic input is compiled with three standard frequency detuning (Δω _I , Δω _∏ , Δω _III ), the logic output X ₁ and Y ₁ are decoded by a certain ratio and delay of the PPLN output of two linearly polarized light intensities, and the logic output X ₂ and _Y2 are decoded by the two linearly polarized light intensities output from the VCSEL. It can be seen from Table 2: Y ₁ =A1⊙A2, Y ₂ =A1⊙A2.

表2Table 2

图3显示了逻辑“非”、“异或”、“异或非”门运算及其延时存储。外加电场，从VCSEL输出的X、Y偏振光强度，以及周期性极化铌酸锂晶体输出的一定比例和延时的X、Y偏振光强度的时间变化轨迹。(a)：点线：逻辑输入dω2；虚点线：逻辑输入dω1；实线：外加电场E₀。(b)外加电场E₀为0kV/mm；虚点线；三个标准频率失谐Δω_I，Δω_∏，Δω_III。(c)外加电场E₀为0kV/mm；虚点线：三个标准频率失谐Δω_I，Δω_∏，Δω_III。Figure 3 shows the logic "not", "exclusive or", "exclusive or not" gate operations and their delayed storage. Applied electric field, X, Y polarized light intensity output from VCSEL, and the time variation trajectory of X, Y polarized light intensity output by periodically poled lithium niobate crystal in a certain proportion and time delay. (a): dotted line: logic input dω2; dotted line: logic input dω1; solid line: external electric field E ₀ . (b) Applied electric field E ₀ is 0kV/mm; dotted line; three standard frequency detuning Δω _I , Δω _∏ , Δω _III . (c) The applied electric field E ₀ is 0kV/mm; dotted line: three standard frequency detuning Δω _I , Δω _Π , Δω _III .

表3给出了逻辑与，以及逻辑与非输入与输出的逻辑关系，以及外加电场与逻辑输入的逻辑关系。逻辑输入用三个标准频率失谐(Δω_I，Δω_∏，Δω_III)来编译，逻辑输出X₁和Y₁通过PPLN输出的一定比例和延时两线性偏振光强来解码，逻辑输出X₂和Y₂通过从VCSEL输出的两线性偏振光强来解码。从表3可得：X₁＝A1·A2，X₂＝A1·A2， Table 3 shows the logic relationship between logic and, logic and non-input and output, and the logic relationship between external electric field and logic input. The logic input is compiled with three standard frequency detuning (Δω _I , Δω _∏ , Δω _III ), the logic output X ₁ and Y ₁ are decoded by a certain ratio and delay of the PPLN output of two linearly polarized light intensities, and the logic output X ₂ and _Y2 are decoded by the two linearly polarized light intensities output from the VCSEL. It can be obtained from Table 3: X ₁ =A1·A2, X ₂ =A1·A2,

表3table 3

表4给出了逻辑与，以及逻辑与非输入与输出的逻辑关系，以及外加电场与逻辑输入的逻辑关系。逻辑输入用三个标准频率失谐(Δω_I，Δω_∏，Δω_III)来编译，逻辑输出X₁和Y₁通过PPLN输出的一定比例和延时两线性偏振光强来解码，逻辑输出X₂和Y₂通过从VCSEL输出的两线性偏振光强来解码。由表4可得：X₁＝A1+A2，X₂＝A1+A2， Table 4 shows the logic relationship between logic and, logic and non-input and output, and the logic relationship between external electric field and logic input. The logic input is compiled with three standard frequency detuning (Δω _I , Δω _∏ , Δω _III ), the logic output X ₁ and Y ₁ are decoded by a certain ratio and delay of the PPLN output of two linearly polarized light intensities, and the logic output X ₂ and _Y2 are decoded by the two linearly polarized light intensities output from the VCSEL. It can be obtained from Table 4: X ₁ =A1+A2, X ₂ =A1+A2,

表4Table 4

图4显示了逻辑与，与非，或，以及或非运算及其延时存储。外加电场，从VCSEL输出的X、Y偏振光强度，以及周期性极化铌酸锂晶体输出的一定比例和延时的X、Y偏振光强度的时间变化轨迹。图中，虚点线：三个标准频率失谐Δω_I，Δω_∏，Δω_III；黑色实线：外加电场E₀。Figure 4 shows the logical AND, NAND, OR, and NOR operations and their delayed storage. Applied electric field, X, Y polarized light intensity output from VCSEL, and the time variation trajectory of X, Y polarized light intensity output by periodically poled lithium niobate crystal in a certain proportion and time delay. In the figure, dotted line: three standard frequency detuning Δω _I , Δω _∏ , Δω _III ; black solid line: external electric field E ₀ .

Claims

1. controlled full light random logic door, it is characterized in that: include successively: tunable continuous wave laser (1), first optoisolator (2), optical attenuator (3), beam splitter (4), main Vcsel (5), second optoisolator (6), first polarization beam apparatus (7), periodically pole lithium columbate crystal (8), 3rd optoisolator (9), second polarization beam apparatus (10), 3rd polarization beam apparatus (11), optical amplifier (12), from Vcsel (13), 4th polarization beam apparatus (14),

The first plane mirror (15), the first half-wave plate (16) and the second half-wave plate (17) also it is parallel with between described beam splitter (4) and main Vcsel (5);

The second plane mirror (18), the first Faraday rotator (19), the 3rd half-wave plate (20) also it is parallel with between described the first polarization beam apparatus (7) and periodicity pole lithium columbate crystal (8);

The 4th half-wave plate (21), the second Faraday rotator (22) also it is parallel with between described the second polarization beam apparatus (10) and the 3rd polarization beam apparatus (11);

Periodically added with transverse electric field E on pole lithium columbate crystal (8)₀(23)。