CN102902011A - Array waveguide grating with insensitive temperature - Google Patents

Abstract

The invention discloses an array waveguide grating with an insensitive temperature. The array waveguide grating comprises an input waveguide zone, an input slab waveguide zone, an array waveguide zone, an output slab waveguide zone and an output waveguide zone which are connected in sequence, wherein the array waveguide zone is embedded with at least two temperature compensation media to realize at least two-order temperature compensation. By adopting the technical scheme provided by the invention, the temperature characteristics of the traditional array waveguide grating can be notably improved, and the temperature insensitiveness of the array waveguide grating can be realized. Meanwhile, as the array waveguide provided by the invention adopts the structural design of a concentric circle, the embedded temperature compensation media are distributed vertically to the array waveguide, thereby effectively reducing scattering loss, realizing symmetry between input and output, and reasonably reducing the overall size of an array waveguide grating device.

Description

A kind of temperature-insensitive array waveguide grating

Technical field

The present invention relates to the optical communication technique field, particularly a kind of temperature-insensitive array waveguide grating.

Background technology

Array waveguide grating (Arrayed Waveguide Grating, AWG) is that a kind of being used for synthesized and separated the sub-device of different wave length, and it can pass through the light of specific wavelength to output port selectively from input port.When being used for by from several entrances and/or to the different wave length light wave of several outlets the time, AWG plays the effect of wavelength multiplexing and/or demodulation multiplexer, is used for synthetic and/or decomposes the different wave length energy.Compare with traditional light multiplexing demultiplexing device spare, AWG has a lot of advantages, and such as favorable expandability, loss is little, and stability is high.Under the driving that cost constantly descends, a lot of equipment are used the merchant and are begun to consider to replace traditional devices with it, and have begun progressively to put it into commercial operation.However, AWG also exists a lot of problems needs further to solve.

In the practical application, AWG must effectively work in a quite wide temperature range.The variation of ambient temperature can cause the variation of thermal expansion and refractive index, thereby so that the light path of Waveguide array change.Different waveguides has different length in the array, and the light path of different waveguide will cause that with different number change the centre wavelength of AWG is drifted about, affect its work, this has limited the widespread use of AWG largely, and therefore, market increases day by day fast to the demand of temperature-insensitive AWG.More common solution is that introducing temperature regulating device and external circuit carry out steady temperature control at present.But will introduce like this power supply and other active equipments, increase on the one hand the complicacy of cost and system, on the other hand, can not put up with for pure optical device group (such as PON etc.).Therefore, need to develop from array waveguide grating device the device of temperature-insensitive.Such as, the scheme by mobile output waveguide, introduce the scheme of the clad material of negative temperature coefficient, scheme etc. by the stress changes refractive index.2009, NTT company has reported the silicon based silicon dioxide AWG of refringence 1.5%, 40 passages, channel spacing 100GHz, the researchist has inserted a kind of medium in Waveguide array, realized the single order temperature compensation, in-5-65 ℃ scope, wave length shift reaches 30pm, insertion loss 1.3-1.9dB, crosstalk-32dB added losses 0.2dB.But this structure has only realized the single order temperature compensation, and structure neither be symmetrical completely, light wave is to plunder the angle outgoing by medium, therefore can introduce large scattering loss, in addition, medium is inserted into the size that also can cause array waveguide grating device in the straight Waveguide array and increases.

Summary of the invention

The purpose of this invention is to provide a kind of temperature-insensitive array waveguide grating, realize at least second-order temperature compensation, by optimizing structure design, implementation structure is symmetrical, to obtain less scattering loss and less array waveguide grating device size.

To achieve these goals, the present invention proposes a kind of temperature-insensitive array waveguide grating, it is characterized in that, this grating comprises: the input waveguide district 1 that connects successively, input waveguide zone 2, Waveguide array district 3, output waveguide zone 4 and output waveguide district 5, wherein:

Described input waveguide district 1 is used for light wave is input to described input waveguide zone 2;

Described input waveguide zone 2 is used for described input waveguide district 1 is propagated each strip array waveguide 7 that the light wave of coming is coupled into described Waveguide array district 3;

Described Waveguide array district 3 comprises many strip arrays waveguide 7, is used for introducing phase differential between the light wave that different Waveguide arrays 7 are propagated, and embeds at least two kinds of temperature compensation media 6 in described some strip array waveguides 7 to realize at least second-order temperature compensation;

Described output waveguide zone 4 is used for the light wave that described Waveguide array district 3 propagates the out of phase of coming is interfered stack;

Described output waveguide district 5 is used for exporting described output waveguide zone 4 and propagates the different wave length ripple of coming.

Preferably, each strip array waveguide 7 comprises: the first tapered transmission line 8 that connects successively, the first straight wave guide 9, the first curved waveguide 10, the second straight wave guide 11, the second tapered transmission line 12, be used for embedding at least two kinds of temperature compensation media 6 to realize at least wide waveguide 13 of second-order temperature compensation, triconic waveguide 14, the 3rd straight wave guide 15, the second curved waveguide 16, the 4th straight wave guide 17 and the 4th tapered transmission line 18, wherein: described the first tapered transmission line 8 links to each other with described input waveguide zone 2, is used for reducing the coupling loss of light wave between described input waveguide zone 2 and the described Waveguide array district 3; Described the first straight wave guide 9, described the first curved waveguide 10 and described the second straight wave guide 11 are all for wave travels; Described the second tapered transmission line 12 is used for forming transition on the width between described the second straight wave guide 11 and the described wide waveguide 13 to reduce loss; Described wide waveguide 13 is used for embedding at least two kinds of temperature compensation media 6; Described triconic waveguide 14 is used for forming transition on the width between described the 3rd straight wave guide 15 and the described wide waveguide 13 to reduce loss; Described the 3rd straight wave guide 15, described the second curved waveguide 16 and described the 4th straight wave guide 17 are used for wave travels; Described the 4th tapered transmission line 18 links to each other with described output waveguide zone 4, is used for reducing the coupling loss of light wave between described Waveguide array district 3 and the described output waveguide zone 4.

Preferably, be manufactured with filling slot 20 in the described wide waveguide 13 to place described temperature compensation medium 6.

Preferably, adopt the mode of spin coating or dipping that described temperature compensation medium 6 is embedded in the described filling slot 20.

Preferably, adopt the mode of heat curing or photocuring that described temperature compensation medium 6 is fixed in the described filling slot 20.

Preferably, the n rank temperature coefficient of described temperature compensation medium 6 is opposite with the n rank temperature coefficient of the sandwich layer 19 of its Waveguide array that will compensate 7, and the n rank absolute value temperature coefficient of described temperature compensation medium 6 is greater than the n rank absolute value temperature coefficient of its described sandwich layer 19 that will compensate decades of times at least, wherein, n is positive integer.

Preferably, the wide waveguide 13 of each strip array waveguide 7 is the concentric structure setting, and each temperature compensation medium 6 of embedding is vertical with the wide waveguide of each bar 13 respectively.

Preferably, the circular arc radius of curvature R of described wide waveguide 13 is determined by the minimum bend loss Bloss of this wide waveguide 13: Bloss=c ₁* exp (a ₁* R), wherein, a ₁, c ₁Be arithmetic number; The crooked subtended angle A of described wide waveguide 13 is determined along the length d on the optical propagation direction in this wide waveguide 13 by described temperature compensation medium 6: A=c ₂* d, wherein, c ₂Be arithmetic number.

Preferably, be equidistant arrangement between the wide waveguide 13 of each bar, the spacing of adjacent wide waveguide 13 satisfies the solution coupling condition shown in the following formula:

$P=\left\{0.5\right[\left\{0.5\right[\&Integral;(E_1^{*}\&times;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">H</figure-callout>}}_2+{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">E</figure-callout>}}_2\&times;$ ${H_1^{*})\mathrm{dS}\}}^2/\{\&Integral;(E_1\&times;H_1^{*})\mathrm{dS}\&Integral;({\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">E</figure-callout>}}_2\&times;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">H</figure-callout>}}_2^{*})\mathrm{dS}\},$ Wherein, E ₁, E ₂, H ₁, H ₂Be respectively the Electric and magnetic fields intensity of two adjacent wide waveguides 13, CT is crosstalking between the adjacent wide waveguide 13, and S is the cross-sectional area of wide waveguide 13, ^*Conjugation is got in expression.

Preferably, the length along optical propagation direction on of same temperature compensation medium 6 in the wide waveguide 13 of difference is unequal, but equates along the length difference on the light wave propagation direction between adjacent wide waveguide 13.

Preferably, described sandwich layer 19 and each temperature compensation medium 6 determined by grating equation along the length difference on the optical propagation direction in adjacent wide waveguide 13, and the differential form of described grating equation is: d (n _cΔ L+n ₁Δ L ₁+ n ₂Δ L ₂+ ...+n _NΔ L _N)/dT=0, wherein, n ₁, n ₂... n _NAnd n _cThe refractive index that represents respectively the sandwich layer 19 of the 1st to N temperature compensation medium 6 and Waveguide array 7, Δ L ₁, Δ L ₂... Δ L _NAnd Δ L represent respectively the 1st to N temperature compensation medium 6 and sandwich layer 19 in adjacent wide waveguide 13 along the length difference on the optical propagation direction, the number N of temperature compensation medium 6 〉=2, T represents temperature.

Preferably, described temperature compensation medium 6 in wide waveguide 13 along the minimum length d on the optical propagation direction _MinMinimum precision by photoetching and etching decides maximum length d _MaxThe maximal value that the extra loss that is brought by embedding temperature compensation medium 6 allows decides.

Preferably, described temperature compensation medium 6 in wide waveguide 13 along the minimum length d on the optical propagation direction _Min, temperature compensation medium 6 in wide waveguide 13 along the maximum length d on the optical propagation direction _Max, wide waveguide 13 minimum concentric circles radius R _Min, wide waveguide 13 maximum concentric circles radius R _Max, same temperature compensation medium 6 between adjacent wide waveguide 13 along the length difference Δ L on the light wave propagation direction _Un, the poor D of neighboring concentric radius of a circle _rBetween satisfy following relation:

Preferably, in the described Waveguide array district 3, the length difference Δ L ' between the adjacent array waveguide 7 is determined by the grating equation of array waveguide grating central wavelength lambda:

$(n_c+\frac{n_1{\mathrm{\&Delta;L}}_1}{\mathrm{\&Delta;L}}+\frac{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">n</figure-callout>}}_2{\mathrm{\&Delta;<figure-callout\; id="2"\; label="L"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}{\mathrm{\&Delta;L}}+......+\frac{n_N{\mathrm{\&Delta;L}}_N}{\mathrm{\&Delta;L}}){\mathrm{\&Delta;L}}^{\&prime;}=\mathrm{m\&lambda;},$ That is: n ' _cΔ L '=m λ, wherein, λ represents the centre wavelength of array waveguide grating, m represents diffraction progression.

Preferably, the employed waveguide material of described array waveguide grating be silicon based silicon dioxide, silicon-on-insulator, indium phosphide, lithium niobate or low-loss polymkeric substance one of them.

The present invention fills at least two kinds of temperature compensation media to realize at least second-order temperature compensation in the Waveguide array of array waveguide grating, can improve significantly the temperature characterisitic of conventional AWG, realizes the temperature-insensitive of AWG; By the optimal design waveguide layout, Waveguide array vertical distribution relative to the temperature compensation medium can effectively reduce scattering loss, and the device input and output have symmetry, reduced the size of array waveguide grating device.

Description of drawings

Fig. 1 is the structural representation of temperature-insensitive array waveguide grating of the present invention;

Fig. 2 is the sectional view of filling slot according to an embodiment of the invention;

Fig. 3 is the sectional view after the temperature compensation medium embeds according to an embodiment of the invention;

Fig. 4 is the wide waveguide detail view in according to an embodiment of the invention Waveguide array district;

The analog transmission spectrum that Fig. 5 is the conventional arrays waveguide optical grating under 20 ℃ and 60 ℃ of temperature;

The analog transmission spectrum that Fig. 6 is temperature-insensitive grating of the present invention under 20 ℃ and 60 ℃ of temperature.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in more detail.

Fig. 1 is the structural representation of temperature-insensitive array waveguide grating of the present invention, as shown in Figure 1, a kind of temperature-insensitive array waveguide grating provided by the invention comprises: the input waveguide district 1 that connects successively, input waveguide zone 2, Waveguide array district 3, output waveguide zone 4 and output waveguide district 5, wherein:

Described input waveguide district 1 is used for light wave is input to input waveguide zone 2;

Described input waveguide zone 2 is used for input waveguide district 1 is propagated each strip array waveguide 7 that the light wave of coming is coupled into Waveguide array district 3;

Described Waveguide array district 3 is used for introducing phase differential between the light wave that different Waveguide arrays 7 are propagated;

The light wave that described output waveguide zone 4 is propagated the out of phase of coming for pair array wave guide zone 3 is interfered stack, the purpose of spatially separating to reach the different wave length ripple;

Described output waveguide district 5 is used for output output waveguide zone 4 and propagates the different wave length ripple of coming;

Described Waveguide array district 3 comprises many (such as 55) Waveguide arrays 7, each strip array waveguide 7 comprises: the first tapered transmission line 8, the first straight wave guide 9, the first curved waveguide 10, the second straight wave guide 11, the second tapered transmission line 12, wide waveguide 13, triconic waveguide 14, the 3rd straight wave guide 15 that connect successively, the second curved waveguide 16, the 4th straight wave guide 17 and the 4th tapered transmission line 18, wherein, described the first tapered transmission line 8 links to each other with described input waveguide zone 2, is used for reducing to input the coupling loss of light wave between waveguide zone 2 and the Waveguide array district 3; Described the first straight wave guide 9, described the first curved waveguide 10 and described the second straight wave guide 11 are all for wave travels; Described the second tapered transmission line 12 is used for forming transition on the width between the second straight wave guide 11 and the wide waveguide 13 to reduce loss; Described wide waveguide 13 is used for embedding at least two kinds of temperature compensation media 6 to realize at least second-order temperature compensation; Described triconic waveguide 14 is used for forming transition on the width between the 3rd straight wave guide 15 and the wide waveguide 13 to reduce loss; Described the 3rd straight wave guide 15, described the second curved waveguide 16 and described the 4th straight wave guide 17 are used for wave travels; Described the 4th tapered transmission line 18 links to each other with described output waveguide zone 4, is used for reducing the coupling loss of light wave between Waveguide array district 3 and the output waveguide zone 4.

Be manufactured with filling slot 20 in the described wide waveguide 13 to place described temperature compensation medium 6, particularly, adopt the mode of spin coating or dipping that temperature compensation medium 6 is embedded in the filling slot 20, adopt the mode of heat curing or photocuring that temperature compensation medium 6 is fixed in the filling slot 20, the sectional view of described filling slot as shown in Figure 2, the sectional view after described temperature compensation medium embeds is as shown in Figure 3.

(n is 1 to the n of described temperature compensation medium 6,2,3, ... etc. positive integer) the rank temperature coefficient is opposite with the n rank temperature coefficient of the sandwich layer 19 of its Waveguide array that will compensate 7, and the n rank absolute value temperature coefficient of temperature compensation medium 6 is greater than the n rank absolute value temperature coefficient of the sandwich layer 19 of its Waveguide array that will compensate 7 decades of times at least.

Embed temperature compensation medium 6 and can cause added losses in wide waveguide 13, the factor that affects described added losses comprises: the number N of temperature compensation medium 6, temperature compensation medium 6 in wide waveguide 13 along the refractive index n of the length d on the optical propagation direction, temperature compensation medium 6 _i, i=1 ... between N, the adjacent temperature compensation medium 6 apart from l.

For the scattering loss that reduces array waveguide grating device and the size of optimizing array waveguide grating device, the concentric structure setting is adopted in the wide waveguide 13 of each strip array waveguide 7, and be equidistant arrangement between the wide waveguide 13 of each bar, each the temperature compensation medium 6 that embeds is vertical with the wide waveguide of each bar 13 respectively, as shown in Figure 4, among Fig. 4, l _MaxBe the distance on maximum concentric circles between the adjacent temperature compensation medium 6, l _MinBe the distance on minimum concentric circles between the adjacent temperature compensation medium 6.

Definite principle of the position of the center of circle O of described concentric structure is to make the length difference of adjacent wide waveguide 13 satisfy grating equation, reduces again the overall dimensions of array waveguide grating device as far as possible; The circular arc radius of curvature R of described wide waveguide 13 is determined by the minimum bend loss Bloss of wide waveguide 13: Bloss=c ₁* exp (a ₁* R) (a ₁, c ₁Be arithmetic number); The crooked subtended angle A of described wide waveguide 13 is determined along the length d on the optical propagation direction in this wide waveguide 13 by temperature compensation medium 6: A=c ₂* d (c ₂Be arithmetic number); Spacing between the adjacent wide waveguide 13 satisfies the coupling condition of separating:

$P=\left\{0.5\right[\&Integral;\left\{0.5\right[(E_1^{*}\&times;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">H</figure-callout>}}_2+{\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">E</figure-callout>}}_2\&times;{H_1^{*})\mathrm{dS}\}}^2/\{\&Integral;(E_1\&times;H_1^{*})\mathrm{dS}\&Integral;({\mathrm{<figure-callout\; id="2"\; label="E"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">E</figure-callout>}}_2\&times;{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">H</figure-callout>}}_2^{*})\mathrm{dS}\},$ Wherein, E ₁, E ₂, H ₁, H ₂Be respectively the Electric and magnetic fields intensity of two adjacent wide waveguides 13, CT is crosstalking between the adjacent wide waveguide 13, and S is the cross-sectional area of wide waveguide 13, ^*Conjugation is got in expression.

The length along optical propagation direction on of same temperature compensation medium 6 in the wide waveguide 13 of difference is unequal, but between adjacent wide waveguide 13 along the length difference Δ L on the light wave propagation direction _UnEquate; Wherein, temperature compensation medium 6 in wide waveguide 13 along the minimum length d on the optical propagation direction _MinBy the minimum precision of photoetching and etching (the minimum precision of common photoetching is about 0.5 μ., the minimum precision of ICP etching is about 1.0 μ .) decide maximum length d _MaxAdded losses by temperature compensation medium 6 is introduced namely embed the extra loss that temperature compensation medium 6 brings, the maximal value that allows (as, 0.4dB) decide; Wherein, temperature compensation medium 6 in wide waveguide 13 along the minimum length d on the optical propagation direction _Min, temperature compensation medium 6 in wide waveguide 13 along the maximum length d on the optical propagation direction _Max, wide waveguide 13 minimum concentric circles radius R _Min, wide waveguide 13 maximum concentric circles radius R _Max, same temperature compensation medium 6 between adjacent wide waveguide 13 along the length difference Δ L on the light wave propagation direction _Un, the poor D of neighboring concentric radius of a circle _rBetween need to satisfy following relation:

$\frac{d_{\min }}{R_{\min }}=\frac{d_{\max }}{R_{\max }}=\frac{{\mathrm{\&Delta;L}}_{\mathrm{un}}}{D_r}.$

The sandwich layer 19 of Waveguide array 7, each temperature compensation medium 6 determined by grating equation along the length difference on the optical propagation direction in adjacent wide waveguide 13, and the differential form of described grating equation is:

D (n _cΔ L+n ₁Δ L ₁+ n ₂Δ L ₂+ ...+n _NΔ L _N)/dT=0, wherein, n ₁, n ₂... n _NAnd n _cThe refractive index that represents respectively the sandwich layer 19 of the 1st to N temperature compensation medium 6 and Waveguide array 7, Δ L ₁, Δ L ₂... Δ L _NAnd Δ L represent respectively the 1st to N temperature compensation medium 6 and Waveguide array 7 sandwich layer 19 in adjacent wide waveguide 13 along the length difference on the optical propagation direction, the number N of temperature compensation medium 6 〉=2, T represents temperature.

In addition, the important feature parameter of array waveguide grating, the length difference Δ L ' between the adjacent array waveguide 7, namely in Waveguide array district 3, light wave can be determined by the grating equation of array waveguide grating central wavelength lambda along the length difference on the direction of propagation:

$(n_c+\frac{n_1{\mathrm{\&Delta;L}}_1}{\mathrm{\&Delta;L}}+\frac{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">n</figure-callout>}}_2{\mathrm{\&Delta;<figure-callout\; id="2"\; label="L"\; filenames="HDA00002218135700031.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}{\mathrm{\&Delta;L}}+......+\frac{n_N{\mathrm{\&Delta;L}}_N}{\mathrm{\&Delta;L}}){\mathrm{\&Delta;L}}^{\&prime;}=\mathrm{m\&lambda;},$ That is: n ' _cΔ L '=m λ, wherein, λ represents the centre wavelength of array waveguide grating, m represents diffraction progression.

By above relational expression, just can determine each structural parameters of temperature-insensitive array waveguide grating.

The employed waveguide material of described array waveguide grating be silicon based silicon dioxide, silicon-on-insulator, indium phosphide, lithium niobate or low-loss polymkeric substance one of them.

If the AWG waveguide material adopts silicon based silicon dioxide, refringence is 0.75% (that is: waveguide under-clad layer refractive index is 1.4452, and the sandwich layer refractive index is 1.4558, and the top covering refractive index is 1.4552), and port number is 8, and channel spacing is 100GHz.This temperature-insensitive array waveguide grating comprises: the input waveguide district 1 that connects successively, input waveguide zone 2, Waveguide array district 3, output waveguide zone 4 and output waveguide district 5; Each strip array waveguide 7 in Waveguide array district 3 comprises: the first tapered transmission line 8 that connects successively, the first straight wave guide 9, the first curved waveguide 10, the second straight wave guide 11, the second tapered transmission line 12, be used for embedding wide waveguide 13, triconic waveguide 14, the 3rd straight wave guide 15 of two kinds of temperature compensation media 6, the second curved waveguide 16, the 4th straight wave guide 17 and the 4th tapered transmission line 18, wherein, the first tapered transmission line 8 links to each other with input waveguide zone 2, and the 4th tapered transmission line 18 links to each other with output waveguide zone 4; Make filling slot 20 in wide waveguide 13, be used for embedding the first temperature compensation medium 21 polyolefin and the second temperature compensation medium 22 silicones; Polyolefinic single order temperature coefficient is-3.65*10 ^-4, the single order temperature coefficient of silicones is-3.7*10 ^-4, the single order temperature coefficient of sandwich layer 19 silicon dioxide of Waveguide array 7 is 1.0*10 ^-5, the single order temperature coefficient of two media is opposite with the single order temperature coefficient of sandwich layer 19 silicon dioxide, and absolute value is greater than the single order temperature coefficient of sandwich layer 19 silicon dioxide more than 30 times; The second-order temperature coefficient of silicones is 1.5*10 ^-7, the second-order temperature coefficient of sandwich layer 19 silicon dioxide of Waveguide array 7 is 1.0*10 ^-7, polyolefinic second-order temperature coefficient is-4.0*10 ^-6, polyolefinic second-order temperature coefficient is opposite with the second-order temperature coefficient of silicones and silicon dioxide, and absolute value more than 20 times, is about 40 times of sandwich layer 19 silicon dioxide second-order temperature coefficients greater than silicones second-order temperature coefficient.

The wide waveguide 13 of each bar is the concentric structure setting, and the first temperature compensation medium polyolefin 21 of embedding and the second temperature compensation medium silicones 22 are all vertical with wide waveguide 13; Be equidistant arrangement between the wide waveguide 13 of each bar, the spacing of adjacent wide waveguide 13 satisfies the coupling condition of separating; The length along optical propagation direction on of same temperature compensation medium 6 in the wide waveguide 13 of difference is unequal, equates along the length difference on the light wave propagation direction between adjacent wide waveguide 13.

Silicon based silicon dioxide AWG by conventional 8 passages of simulation calculation, channel spacing 100GHz and the AWG structure of the present invention's proposition are transmission spectrum under 20 ℃ and 60 ℃ in environment temperature, can find out, be changed to by 20 ℃ in environment temperature under 60 ℃ the condition, drift has occured in the spectral line (as shown in Figure 5) of conventional AWG, and the AWG structure that the present invention proposes is changed to by 20 ℃ in temperature under 60 ℃ the condition, spectral line (as shown in Figure 6) does not drift about, having realized temperature compensation, is temperature-insensitive.And, Waveguide array of the present invention adopts the concentric structure design, so that the temperature compensation medium vertical distribution relative to Waveguide array that embeds reduced scattering loss effectively, realized that input and output are symmetrical, and reasonably reduced the array waveguide grating device overall dimensions.

Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of making, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (15)

1. temperature-insensitive array waveguide grating, it is characterized in that, this grating comprises: the input waveguide district (1) that connects successively, input waveguide zone (2), Waveguide array district (3), output waveguide zone (4) and output waveguide district (5), wherein:

Described input waveguide district (1) is used for light wave is input to described input waveguide zone (2);

Described input waveguide zone (2) is used for described input waveguide district (1) is propagated each strip array waveguide (7) that the light wave of coming is coupled into described Waveguide array district (3);

Described Waveguide array district (3) comprises many strip arrays waveguide (7), be used between the light wave that different Waveguide arrays (7) are propagated, introducing phase differential, embed at least two kinds of temperature compensation media (6) in described some strip array waveguides (7) to realize at least second-order temperature compensation;

Described output waveguide zone (4) is interfered stack for the light wave of described Waveguide array district (3) being propagated the out of phase of coming;

Described output waveguide district (5) is used for exporting described output waveguide zone (4) and propagates the different wave length ripple of coming.

2. temperature-insensitive array waveguide grating according to claim 1, it is characterized in that, each strip array waveguide (7) comprising: the first tapered transmission line (8) that connects successively, the first straight wave guide (9), the first curved waveguide (10), the second straight wave guide (11), the second tapered transmission line (12), be used for embedding at least two kinds of temperature compensation media (6) to realize at least wide waveguide (13) of second-order temperature compensation, triconic waveguide (14), the 3rd straight wave guide (15), the second curved waveguide (16), the 4th straight wave guide (17) and the 4th tapered transmission line (18), wherein:

Described the first tapered transmission line (8) links to each other with described input waveguide zone (2), is used for reducing the coupling loss of light wave between described input waveguide zone (2) and the described Waveguide array district (3);

Described the first straight wave guide (9), described the first curved waveguide (10) and described the second straight wave guide (11) are all for wave travels;

Described the second tapered transmission line (12) is used for transition on formation width between described the second straight wave guide (11) and the described wide waveguide (13) to reduce loss;

Described wide waveguide (13) is used for embedding at least two kinds of temperature compensation media (6);

Described triconic waveguide (14) is used for transition on formation width between described the 3rd straight wave guide (15) and the described wide waveguide (13) to reduce loss;

Described the 3rd straight wave guide (15), described the second curved waveguide (16) and described the 4th straight wave guide (17) are used for wave travels;

Described the 4th tapered transmission line (18) links to each other with described output waveguide zone (4), is used for reducing the coupling loss of light wave between described Waveguide array district (3) and the described output waveguide zone (4).

3. temperature-insensitive array waveguide grating according to claim 2 is characterized in that, is manufactured with filling slot (20) in the described wide waveguide (13) to place described temperature compensation medium (6).

4. temperature-insensitive array waveguide grating according to claim 3 is characterized in that, adopts the mode of spin coating or dipping that described temperature compensation medium (6) is embedded in the described filling slot (20).

5. temperature-insensitive array waveguide grating according to claim 3 is characterized in that, adopts the mode of heat curing or photocuring that described temperature compensation medium (6) is fixed in the described filling slot (20).

6. temperature-insensitive array waveguide grating according to claim 2, it is characterized in that, the n rank temperature coefficient of described temperature compensation medium (6) is opposite with the n rank temperature coefficient of the sandwich layer (19) of its Waveguide array that will compensate (7), and the n rank absolute value temperature coefficient of described temperature compensation medium (6) is greater than the n rank absolute value temperature coefficient of its described sandwich layer (19) that will compensate decades of times at least, wherein, n is positive integer.

7. temperature-insensitive array waveguide grating according to claim 2, it is characterized in that, the wide waveguide (13) of each strip array waveguide (7) is the concentric structure setting, and each temperature compensation medium (6) of embedding is vertical with the wide waveguide of each bar (13) respectively.

8. temperature-insensitive array waveguide grating according to claim 7 is characterized in that, the circular arc radius of curvature R of described wide waveguide (13) is determined by the minimum bend loss Bloss of this wide waveguide (13):

Bloss＝c ₁*exp(-a ₁*R)，

Wherein, a ₁, c ₁Be arithmetic number;

The crooked subtended angle A of described wide waveguide (13) is upward determined along the length d on the optical propagation direction in this wide waveguide (13) by described temperature compensation medium (6):

A＝c ₂*d，

Wherein, c ₂Be arithmetic number.

9. temperature-insensitive array waveguide grating according to claim 7 is characterized in that, is equidistant arrangement between the wide waveguide of each bar (13), and the spacing of adjacent wide waveguide (13) satisfies the solution coupling condition shown in the following formula:

$\mathrm{CT}={\log }_{10}^P,$

$P=\left\{0.5\right[\&Integral;\left\{0.5\right[(E_1^{*}\&times;H_2+E_2\&times;{H_1^{*})\mathrm{dS}\}}^2/\{\&Integral;(E_1\&times;H_1^{*})\mathrm{dS}\&Integral;(E_2\&times;H_2^{*})\mathrm{dS}\},$

Wherein, E ₁, E ₂, H ₁, H ₂Be respectively the Electric and magnetic fields intensity of two adjacent wide waveguides (13), CT is crosstalking between the adjacent wide waveguide (13), and S is the cross-sectional area of wide waveguide (13), ^*Conjugation is got in expression.

10. temperature-insensitive array waveguide grating according to claim 7, it is characterized in that, the length along optical propagation direction on of same temperature compensation medium (6) in the wide waveguide of difference (13) is unequal, but equates along the length difference on the light wave propagation direction between adjacent wide waveguide (13).

11. temperature-insensitive array waveguide grating according to claim 10, it is characterized in that, described sandwich layer (19) and each temperature compensation medium (6) are gone up in adjacent wide waveguide (13) and are determined by grating equation along the length difference on the optical propagation direction, and the differential form of described grating equation is:

D (n _cΔ L+n ₁Δ L ₁+ n ₂Δ L ₂+ ...+n _NΔ L _N)/dT=0, wherein, n ₁, n ₂... n _NAnd n _cRepresent that respectively the 1st arrives the refractive index of the sandwich layer (19) of N temperature compensation medium (6) and Waveguide array (7), Δ L ₁, Δ L ₂... Δ L _NReach Δ L and represent that respectively the 1st is upper along the length difference on the optical propagation direction in adjacent wide waveguide (13) to N temperature compensation medium (6) and sandwich layer (19), the number N of temperature compensation medium (6) 〉=2, T represents temperature.

12. temperature-insensitive array waveguide grating according to claim 7 is characterized in that, described temperature compensation medium (6) is upper along the minimum length d on the optical propagation direction in wide waveguide (13) _MinMinimum precision by photoetching and etching decides maximum length d _MaxThe maximal value that the extra loss that is brought by embedding temperature compensation medium (6) allows decides.

13. temperature-insensitive array waveguide grating according to claim 7 is characterized in that, described temperature compensation medium (6) is upper along the minimum length d on the optical propagation direction in wide waveguide (13) _Min, temperature compensation medium (6) is upper along the maximum length d on the optical propagation direction in wide waveguide (13) _Max, wide waveguide (13) minimum concentric circles radius R _Min, wide waveguide (13) maximum concentric circles radius R _Max, same temperature compensation medium (6) between adjacent wide waveguide (13) along the length difference Δ L on the light wave propagation direction _Un, the poor D of neighboring concentric radius of a circle _rBetween satisfy following relation:

$\frac{d_{\min }}{R_{\min }}=\frac{d_{\max }}{R_{\max }}=\frac{{\mathrm{\&Delta;L}}_{\mathrm{un}}}{D_r}.$

14. temperature-insensitive array waveguide grating according to claim 1, it is characterized in that, in the described Waveguide array district (3), the length difference Δ L ' between the adjacent array waveguide (7) is determined by the grating equation of array waveguide grating central wavelength lambda:

$(n_c+\frac{n_1{\mathrm{\&Delta;L}}_1}{\mathrm{\&Delta;L}}+\frac{n_2{\mathrm{\&Delta;L}}_2}{\mathrm{\&Delta;L}}+......+\frac{n_N{\mathrm{\&Delta;L}}_N}{\mathrm{\&Delta;L}}){\mathrm{\&Delta;L}}^{\&prime;}=\mathrm{m\&lambda;},$ That is: n ' _cΔ L '=m λ, wherein, λ represents the centre wavelength of array waveguide grating, m represents diffraction progression.

15. temperature-insensitive array waveguide grating according to claim 1 is characterized in that, the employed waveguide material of described array waveguide grating be silicon based silicon dioxide, silicon-on-insulator, indium phosphide, lithium niobate or low-loss polymkeric substance one of them.

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